Thanks so much for watching everybody, and thanks to our sponsor - head to www.Brilliant.org/CoolWorlds to learn more! Let me know down below which resolution you prefer, and if there are any other apparent cosmic paradoxes that keep *you* awake at night?
as always, your videos make me regret not studying astrophysics at university... you are one of my favourite scientists in the world! love your story-telling style
The Sun is indeed white if viewed in space, but when we view it usually appears yellow due to several effects, I didn’t really want to get into the nuance of this as it’s mostly irrelevant to the video so we’ll just stick with the colour most people see!! (I posted a more detailed explanation about this as a separate comment)
You can't even imagine how many times I have refered to your videos while discussing the universe with people (sober or not). Cool Worlds has become my favourite channel and made me even more interested in the universe and everything about it!
when I was young, I was enthralled to sit and listen to Carl Sagan for hours. Now there is David Kipping to take his place and enthrall my sense of intrigue and wonderment. Keep up the good work David
Yep. Totally Sagan reincarnate. It's something in the voice, mannerisms, presentation, wording, structure...je ne sais quoi. Calm, clear and therapeutic. Only some have it by sheer luck and it can't be faked. Needs to go mainstream badly and replace that dirty manc accent of cox on TV.
My guess is that most red dwarf stars' heliospheres are not powerful enough to shield their planets from the highly-energetic interstellar medium. It's probably something like standing underneath an umbrella in a rainstorm as opposed to standing underneath a full roof. Planets orbiting red dwarfs might be close enough to their star to hold liquid water and maybe even a stable climate, and might even be sufficiently shielded from the interstellar medium. But at that range, those planets are probably close enough to their red dwarf to feel the wrath of its problematic mood swings that red dwarfs are notorious for.
It's also likely that any planet in a red dwarf's 'goldie locks' zone will be tidealy locked to their sun and will have one side always facing the sun.
My favorite theory is that the red dwarf stars have an equal probability of hosting life with our sun, but that it takes longer for that life to initially emerge. As mentioned, red dwarfs are unstable at the beginning, and the universe is only 13 billion years old. Perhaps yellow stars are simply more conducive to creating life more early in the span of the universe.
"The universe is only 13 billion years old." This idea is being challenged, because the Universe is expanding at such a rate that there are parts of the Universe we cannot ever see (from Earth) due to the amount of space being created. Literally, beyond the furthest reaches of the Universe we can see, more space is being added than light can traverse, so the light never reaches us. Thus we have no idea how big our Universe actually is, or how old, since we literally can't see that far back. Remember, when we look up into the sky, we are also looking into the past: we see the moon as it was 1 second ago, the Sun 8 minutes ago, the star Alpha Centauri as it was 4.3 years ago, as it takes that long for light from those objects to reach us. 13 billion years is about how far we can "see" - anything further away, we literally can't see because the light can't reach us. So that 13 billion number is actually a minimum, based on current available observation. The Universe could be 80 trillion years old, for all we know.
Fascinating work, thank you. But how does the age of the universe affect this? It seems to me that considering our earth is about one third the age of the universe, it doesn't matter that red dwarfs can last so much longer than our sun. They only have lasted at most 3 times as long, and on average something like 1.5 times as long. -Adrian in Australia
Even worse, the early red dwarfs (and their possible planets) were formed long before there were heavy elements with which to form planets… and life. In fact, the era when there were significant heavy elements was approximately when the Sun formed. The only stars we should be comparing with are the other stars formed in that era. Lifespan of the red dwarfs is thus irrelevant.
@@jursamaj This is exactly right and a well known fact whenever considering life formation. To be more precise we need a high enough density of phosphorus to allow for organic chains. Second there is likely no chance for photosynthesis at infrared (or it would have likely evolved on Earth by now). Third there is a mess with tidal locking and tidal forces
You could think of life span as a fuel tank, the star dies when it runs out of fuel, the ages of these stars are simply calculated by the rate at which they use energy not by direct observation.
And just to answer a common question I’m seeing: isn’t the Sun white? First, the Sun appears yellowish to us when we usually look at it due to a combination of effects such as safe viewing elevations and Rayleigh scattering. So culturally we think of the Sun as yellow. In space it would look closer to white though. A second complication is that when an astronomer says “white dwarf” they’re actually referring to a post main sequence stellar remnant, the Sun is not (yet) a white dwarf so we can’t use that language to describe it because it implies a very different object! For this reason FGKs tend to be referred to as yellow dwarfs (orange for later K types). I didn’t really want to spend too long explaining this in the video because it’s frankly irrelevant to the topic but enough if you asked about this that I wanted to clear it up!
Am I wrong for thinking all stars would look more or less white because they emit the entire spectrum of visible light, it's just which wavelength is the most prevalent that gives them their "colour"?
My guess is that planets in the Goldilocks zone of red dwarves would be tidal locked (no seasons, no day/night cycle) and would have no or tiny moons (no tides). That's a tough recipe for life, let alone intelligence to emerge.
There's also the possibility that planets in the Goldilocks zone would suffer solar winds powerful enough to sterilize surface life such as cyanobacteria.
@@weltraumameisenbaer8789 IO's orbit is pretty elliptical and irregular, and the tides are a result of that and the tug of war between Jupiter and the other 3 Galilean moons upon it. By definition, any planet would have cleared its orbit and thus would not have a 3 body problem going on. The orbit would be circular and regular and would not have any other outside influence on it. What you are describing would be something more akin to an asteroid belt body rather than a planet.
Temporal paucity, but the opposite of what you proposed. All red dwarf systems are young now. Even the oldest are barely to 5% of their lifespans. Our system didn't evolve intelligence till our star was at 80% of it's stable lifespan, and red dwarfs take even longer to settle down.
this is my thought also. the solar system is 5~ billion years old in a supposedly 14~ billion year old universe. We are so early to the scene it's not funny. You can't even compare red dwarfs fairly because red dwarfs might live for 100 trillion years but we haven't even come close to that figure yet so their lifespan increase is negligible. I think it's pretty likely that the first 5-10 billion years of the universe were probably more inhospitable for life due to just way more crap going on, so it seems reasonable to me that we could actually be part of the first generation of life. That's not an implication we are the *first* life, just part of the early generations of it, which also explains our loneliness because the light from other early generation life can't reach us yet. It's all speculation of course, but to me this seems more feasible than not.
@@empty5013 this makes the most sense to me. We exist all as vibrations of crazy ass particles and quarks. We are an example of when things go right for life it will find a way. We mustn’t let the future and possibly other reality frequency vibrating beings out there down!
I was under the impression that these M dwarf stars flare so frequently and the habitable zones are so close, it would either completely strip any atmosphere away and/or cause it to become tidally locked. I thought this made the idea of habitable planets around them to be a complete no-go? Would an Earth-sized planet with an Earth-equivalent magnetic field be able to stop an M dwarf star from stripping its atmosphere away from such a close orbit?
@@frankkolmann4801 Not to mention the glaring issue with the 1 percent statistic in the video - while it's true that red dwarf stars have the time advantage with a lifespan of up to trillions of years, Dr. Kipping pointed out in the video that the universe has not even _existed_ for trillions of years, hardly having passed 10 billion years of age. The time advantage that red dwarfs have for evolution hasn't even _had time_ to come into play yet, since most yellow (technically white) dwarfs are still very much alive and in the main sequence. Again as said in the video, at the current point in the universe, there are only 5 times as many main sequence red dwarfs as yellow dwarfs. This brings the red sky paradox chances back up to 1 in 5 for us at this point in the universe's history, even with all else being equal, making Resolution 1 look much more likely again (although a yellow-sky alien in a trillion years would have much more to think about!) Then you add in what you and OP said, and suddenly there are even more factors indicating that a red dwarf civilization would not be so likely after all, and might be quite rare indeed... at least, for now. {{ More below, about additional alien paradoxes related to the red sky paradox}} That brings up the obvious but lesser "orange sky paradox" questioning why we live around a G type sun-like star instead of an orange K-type, which is the relatively mellow, fairly long-lived halfway point between us and the M-type red dwarfs. These stars are less likely to be turbulent for their home planets than the red dwarves, meaning they might have a slight numbers advantage that isn't cancelled out by their absence of a habitable zone. But again, their time advantage has not yet taken place, so this is not likely to cause a significant gap yet. And as a way to wrap this whole argument of mine up: We can't make accurate theories about the accuracy of the cosmological principle or the differences between ourselves and aliens, due to our sample size of... us. Unless we're the only aliens in the universe or one among very few, that's not a very good sample size for any study. Which naturally leads into the Fermi Paradox - why _haven't_ we found anyone else? Well, for all the debating we've done about the Fermi Paradox, many have based their assumptions around a flawed premise - that if aliens were out there, even fairly close and rather loud, we would have already and quite easily picked them up. This is simply not true, not even assuming that they're broadcasting in the right frequencies and with sufficient strength for us to pick them up. Refer to the universal constant that terrorizes sci-fi authors, xenobiology theorists, and rocket scientists everywhere - the speed of light. The first radio broadcast ever sent by humanity was sent 127 years ago. Naturally, this means it has traveled 127 light-years. Even assuming the weak and muddled signal hasn't dissolved into background static over that distance, it's only reached the closest 6,000 or so stars to us, and if there's an alien race with about the same technology as us 100 light years away that received the signal 20-something years ago and blasted something back, we won't know about it for another 73 years at best! Look at the fact that the Milky Way is about 100,000 light years across, and you realize it'll likely be a different geologic era before we get a reply to something we shot out into the cosmos, and twice as long before we can be sure they've received our message back. Forget deciphering the alien message - it'll be almost as difficult to figure out what WE sent so long ago! This applies the other way around, too - for us to discover aliens 500 light years away, they have to have shot a signal strong enough to detect, directly at us, 500 years ago. Considering that a signal that strong and focused would be a pretty big task even for us now, that raises the question of just how long ago we really expect aliens to have _had_ such advanced tech, or if that'd be so rare that nobody in range would have developed it yet. This difficulty goes up by orders of magnitude if we ever expect to have a Star Trek future of hopping from planet to planet and meeting a vast variety of different species face-to-face in our travels: such journeys would take thousands of years, and by the time Captain Kirk's ship would have returned, the descendants of his crew could have evolved to become just as alien to us as we were to Neanderthals!
Bro, not all red dwarfs are flare stars! Plus YOU COULD ACTUALLY LIVE IN A FLARE STAR IF YOU HAVE A STRONG MAGNETIC FIELD AND GRAVITY. In fact, red dwarf stars do have a habitable zone uncultured swine.
@@frankkolmann4801 "Red dwarf stars have no habitable zone." That's not entirely true. The larger the star, the larger the habitable zone, but the shorter the life span of the star. This is why we don't look for intelligent life in blue supergiant systems, because the star itself only lasts for millions of years, not the requisite billions+ for evolution of intelligent life as we know it. Further, our own Sun is considered a G-type star, technically a "yellow dwarf", one size in range larger from red dwarfs. This is just to put the discussion in perspective. As covered in this video at 3:24, red dwarf stars have a range of sizes. If we were to go hunting for intelligent life in red dwarf systems, if I were to choose, I would target the larger red dwarfs, closer to the 1/2 the size of the Sun category, rather than the tinier red dwarfs closer to the size of Jupiter. Why? The habitable zone point brought up in this thread. The smaller stars _effectively_ have no habitable zone (too small in range that the odds of a planet being placed just right make looking for them almost a fool's errand.) Then there is the additional factor that makes looking for life on such stars moot. What is that additional factor? As a star ages during its main phase (the longest phase, where it burns hydrogen for energy), its nuclear reaction and heat output goes up to compensate for the increase in helium in its core. Our own Sun is 30% brighter now than it was 5 billion years ago, if I recall correctly. As the energy output increases, so does the habitable zone "range" - but the habitable zone also moves further away from the star. 5 billion years ago, Venus was more ideally placed in the habitable zone as back then the zone was a little closer to the Sun due to the lowered energy output. As of now, Earth is ideally placed. In a red dwarf system (assuming this star is half the size of our Sun as an example), a planet just outside the habitable zone at formation 10 billion years ago might be ideally placed in it today, with life only now starting to thrive on it.
you are likely right see my reply to too cool worlds lab, and the reference that supports exactly what you said. who is likely no Red sky paradox, several publications support that m dwarf exoplanet would require a huge magnetosphere to keep an atmosphere especially in the nearby habitable zone. if we can agree mars never had any intelligent life, what is believed to have had water, and had its atmosphere stripped away, studies CME-solar winds have estimated m dwarf exoplanets require magnetosphere many times earths not to have its atmosphere stripped away like mars.
Great video, as always - but is the time really an important part of the equation (for now) since our universe has "only" a few billions years? And heavier elements are even more recent? I mean, aren't most red sky worlds just as young as Earth?
I was thinking this too. What does it matter if they can last trillions of years? The universe isn't that old yet. Moreover, I'm a geologist, and I have a running intuition that says that the window for lie to develop on a world is relatively short after it's creation (on a timescale of billions of years). Either the world is going to go snowball and not develop life (in the case of red dwarfs this is even worse, since they are most energetic when young), or it will go hothouse like venus (more common around sunlike stars where the sun's power gradually ramps up). At least in earth's case, it seems that the earth's temperate climate has been stabilised by feedback loops of CO2 and O2 that life itself is responsible for. For Earth, life seems like it was necessary to prevent it turning into a second venus.
@@Phoenixash-delfuego algorithms and payed for advertising 🤦♂️ theres years old vids from people i follow ive never seen but youtube keeps throwing tik tok shite at me lol
@@roydoncrerar2852 my thoughts exactly. Too many people nowadays are so addicted to themselves & to the mindless egotistical content of others (esp on social media) that they literally can't see beyond that. Since I was a kid I've always paused in wonder to look up at the moon every time I see it in the sky. Our original Cool World. The only celestial body that we can see as a sphere with details on, & my introduction as a child to the Universe beyond. How many people do that these days? Far too few in my opinion. Channels like this will hopefully change that...
Like others, watching your videos I find myself wondering whether I should have become an astrophysicist instead of a philosopher! Simply wonderful stuff.
The solution for your dilemma is quite simple in my opinion. The spectrum of red dwarf is shifted toward less energetic wavelengths. We all are familiar with the necessity of light to excite reactions and we know that life form began in the sea - well - the spectrum of absorption in the ocean is the lowest around 400nm which is also the heights peak of the sun (the emission of red dwarf is 1000nm - which is almost completely absorbed by the oceans themselves). My assumptions are that in order to create life one needs both a solution (i.e. water which allows for chaotic environment) and an exiting force for interatomic/molecular reactions/interactions - a wavelength around 400nm is equivalent to ~3.1eV which is more than enough to allow for redox reactions as well as band gap excitations.
works for me. To be honest this just seems as a desperate grab for content. This isn't a paradox, it's just a question, a question with what I suspect will be a trivial answer. Case and point the explanation given by Nir Ophek
We don't "know" that life "began" in the sea. Are you serious with that statement??? There's no evidence whatsoever that life came from non-living material, ever. It's mind boggling where scientists and other people get off saying stuff like that when it's never something that's been observed and there's no evidence for at all. What the hell is wrong with our scientists these days? Abiogenesis is the dumbest thing holding humanity back from actually progressing in our knowledge, it's so ridiculous and frustrating.
Wow I just realized he barely uses any cuts/edits, if any. Usually youtubers have a cut every 5 seconds. Just a naturally talented speaker. Great video as always. Never thought about this question until now, and now I'm intrigued!
He often cuts to a diagram or visual aid while talking. Clever editing can hide a lot of things, but it does seem as though the scripts are incredibly well rehearsed.
Well, he does give lectures as a professor and as a speaker so I'm guessing he's used to it. I personally like it better with out cuts even if there is a mistake. It's just RUclips, not an actual TV show in LA or something. lol.
Could it be that red dwarfs being smaller have habitable zones closer that makes exposition to solar phenomena being hazardous places to develope life (as we know it)?
That was my thinking...and also because of that many planets within the habitable zones of these starts would be tidally locked, making them virtually uninhabitable. Though they say habitability within the "twilight zones" of those planets could be possible, it seems unlikely that life could persevere in such a small sliver of an entire planet.
@@100percentSNAFU I agree with the 2 commenters above..all the radiation, solar eruptions, solar wind, and being tidally locked dont spell out a good chance of life..i.e. proxima b
Life is much more resilient than we tend to think. Even if tidally locked and bombarded with radiation, an underground ocean would be able to host life.
Yes, this video is a joke. Red dwarfs are much more active than our sun, making life harder. And as you said planets would also have to he closer to be in the habitable zone resulting in even more exposure to dangerous radiation. This video was pretty pointless im ngl.
Does he seriously not address this in the video? With a title such as this one I’d assume these basic factors would be looked at. But it seems like (what I’m getting from the comments) is that he went out of his way to present it as much more of a paradox than it is. He even responded to a comment by saying “you make a good point and I have no rebuttal but I’m stubborn so I still don’t agree with you.”
I had always assumed it was widely accepted that red dwarfs were just way to active and due to the proximity between the stars and planets causing tidal locks, no life like ours would be able to evolve. That or our kind of life simply cannot exist beyond a system like ours.
I've seen a few people respond with this which is what I originally thought aswell. Makes you wonder why this guy would totally ignore this possibility?..
@@himynameis3664 From an optimistic standpoint, he simply ignores it to make the arguments for such a paradox more convincing. From a pessimistic standpoint, his simply trying to click bait people who don't know any better.
@@musicheaven1679 Yeah, after watching the entirety of the vid I think he did kind of mention it but he glossed over it so quick I nearly missed it. And for something that pretty much resolves the "paradox" it shouldn't be glossed over.
The thing that makes me most skeptical about red dwarfs being able to support life is that most red dwarfs’ habitability zone is so close that the planet would be tidally locked and you might only get a ring of temperate conditions between the hot and cold sides. It seems so unlikely to work out just right. However, “eyeball planets” as they are called are really cool to imagine in like a sci-fi setting and I hope I am wrong.
I went camping the other night up in the mountains near Mt. St. Helens in Washington State and thought a lot about the last video about how big the universe is while I was up there. There's nothing quite like staring up in the sky on a clear night with no light pollution and pondering the universe. It's a magical experience.
Yup. Both of those look like subtypes of resolution II. I'd have been happier to have the tidal locking problem at least mentioned in the video... I'll be happier about knowing what explanation is plausible when we can at least detect water vapor (or its absence!) in the atmospheres of these worlds (as an index of how bad the flare damage is) and preferably to also detect oxygen. One other possible resolution to the Fermi paradox as a whole might be from the expected water abundance on superearths. Some of the models predict oceans hundreds of kilometers deep on most of them. Perhaps near-Earth-mass worlds are mostly divided between waterless, lifeless worlds and ocean worlds with plenty of life, but no dry land, or land animals, or technology. Worlds with just the right amount of water to spawn life but also with dry land and fire-wielding technologists might be exceedingly rare.
Red dwarves will, eventually, calm down and flaring will stop. Plenty of them are already pretty timid. In my opinion, it's just too early. In older universe planets around them could boom with life. We are most likely one among the first few odd civilizations in the universe, and also incredibly lucky.
@@Mandrak789 heres a thought experiment. We are refugees of a much older race of beings, a progenitor race that evolved in a much younger universe cast adrift in the universe after their home world/local star cluster expired. This progenitor race had the technology to manipulate the orbits of planets, being directly resposible for tidal locking and sun/moon cycles to create the conditions for us to exist on this planet to their specifications. They then left and continued to seed life in other locations, the only trace of them existing left in ancient structures and myth and our genetics..
@@livinglight9915 ah yes that's one of my fav scenarios, although it must be worked out in details to be believable; lot of plot holes there unfortunatelly
@@Mandrak789 I see conflicting reports on how much red dwarves settle down. E.g. www.universetoday.com/148709/even-older-red-dwarf-stars-are-pumping-out-a-surprising-amount-of-deadly-radiation-at-their-planets/ says Barnard's star, 10-12 billion years old, is still flaring 25% of the time. The other question is, even if the flaring eventually stops, if planets' atmospheres were stripped by the flaring, is there any mechanism to replenish them? Hopefully we'll eventually be able to observe the atmospheres and see what survived or was replenished - or not.
It really pains me when people plug in 20% for the fraction of stars with habitable planets in the Drake Equation given the Red Sky Paradox. Thanks for this brilliant work which sheds direct sunlight (Ha!) on this matter.
If Life can only arise around G type stars then ~7% becomes the upper bound for the fraction of stars with habitable planets. (not an unreasonable assumption). Also...if my aunt had balls she'd be my uncle but she doesn't(as far I know) so she's not.
I think its because those people are afraid to accept the fact that its highly likely they're not the most intelligent species in the Universe. Especially if some of them have the technology to travel through interstellar space in order to come visit us, and observe us as we do animals in the wild or the zoo.
Maybe they should split habitable zone into suitable for life to evolve vs us being already evolved being able to live there. From what i understand brown dwarfs have VERY violent activity. Like way way waaaaaay more violent then our sun. In fact, if you look all the other solar systems we've discovered so far and compare them to ours, our solar system is STRIKINGLY orderly. Not saying it was constructed, but if thats what it takes to get life to evolve, then life is probably REALLY rare.
Maybe there is something I’m missing here, but haven’t we just not had enough time for this to play out yet? The universe is “only” ~14 billion years old. How could red stars enjoy a time factor of 20 when there hasn’t been enough time yet for them to outlive stars like the sun (lifespan of about 10 billion years) by that amount?
Excellent video as always, but I'm wondering how the age of the universe factors in. If the universe is only 13.7 billion years old, then why does it matter that red dwarfs can last for trillions of years? It would seem that while the universe is still relatively young, the likelihood of life and civilizations evolving around any type of star with habitable planets would be more or less equal. In half a trillion years there may be far more civilizations around red dwarfs than other stars, but at this stage they haven't had that advantage yet. What am I missing?
I think that when we're talking about the fermi paradox we're talking about why we're seemingly the only life in the universe. If we're the first planet with intelligent life, and there's an X% chance for life to arise per year, it would stand to reason that there being 5x as many red dwarfs, and their longer life spans make it more likely for any original life developed between now and the end of the universe to find themselves looking up at a red dwarf sun. So the question is why are we so early to arise here instead of around a red dwarf say a trillion years from now. We could have developed at any point in the future of the universe as well, which is why the long lifetimes of red dwarfs are relevant and might be more likely sources for original life to develop far into the future. I tend to think we just got lucky and are one of the first intelligent species in the universe, but that there will be many more, and many/most of them will be around red dwarf suns.
Do your solutions take into account the metallicity of stars that form at different points in time in the universe's history? If stars only formed with enough metals to spawn in the last 4 or 5 billion years then it could nullify the time factor for red dwarfs at this point in time, as it would mean red dwarfs with enough metals to form life haven't existed long enough to have a time advantage over M type stars that formed in the same period.
Yeah, we really are almost as soon as we could have been on a cosmic scale. The entire universe is barely three times as old as our solar system, and you have to take into account that metals and heavier elements just didn't exist at first. It's pretty crazy to think about. Life has existed on Earth as soon as it was possible, and an habitable planet like Earth existed as soon as it could. We are merely wotnessing the dawn of life and civilisation in the universe.
@@leirbag1595 Very excellent points. The Red Sky Paradox doesn't even mention tidal locking (which is huge) and greatly downplays solar flares. So I doubt it considers what you mention, which is something else that likely nullifies it. Sad, but this "paradox" does not appear to be any better than the Drake equation. But, anyway, I've seen and read some really interesting stuff that DO account for the age of stars / presence of metals and when life first began on Earth that do seem to indicate that life began pretty damn quick, pretty much as early as it possibly could have. Which helps towards the case that life may actually be very prevalent in the universe. Now, intelligent life is a totally different thing though - intelligence may be rare even if life is very common. We have no way of knowing how common intelligence is, and probably won't for quite some time.
@@Me__Myself__and__I Multicellular life needed a billion years before it was able to form on Earth, so we will likely only witness intelligent life on planets which are consistently habitable. Though to address tye solar flares and tidal lockings around red stars, an underground lifeform would be sufficiently protected from the former and might evolve to resist them, and a tidal lock, while unquestionably shitty, leaves an habitable zone with an unending twilight. The conditions on a planet like that would be much more difficult than usual, but given that these worlds would have more time to develop, they might still develop life. Intelligent life should still be extremely rare, especially human-level intelligence. Goven how long it took for us to appear and how specific our evolutionary path was, most worlds would likely just not recreate them. Otherwise, yeah there is definitely life out there. Even just in the solar system, there are three other places than Earth that I can think of that ccould be hosting life, plus others which could in the future.
@@leirbag1595 I don't recall the exact details, but multi-cellular life did not take a billion years. Early earth had issues such as asteroid impacts, high temperature, etc. that would have precluded life at the beginning. Once you subtract that time out life took less time to develope. The thing with Red / M Dwarves is that they haven't really had all that much more time. This video says 20x, but the universe isn't old enough to allow that. Plus, the earlier generations of stars didn't have enough heavy elements available yet. So when you discount the 15x+ time of red dwarves (that hasn't yet occurred) and the earlier timeframe where there weren't yet enough heavy elements - M Dwarves really haven't had much additional time over our star in the present day.
Thanks, I wanted to write the same. There is no star in the Universe that is much older than 3 times the age of the sun. The factor of 20x is wrong. I was shocked when he mentioned it.
He tries to shift the argument and say that you can't limit it to one point in time. Okay, but that demolishes the argument because I can just as easily say you can't limit it to one point in space. If you limit the argument to why present-day humans exist around a G type star, then it has to be PRESENT DAY. He can't have it both ways.
I love how you've been thinking of so many topics in astronomy that others seem to ignore, like red dwarf planet's odds of having life, and exomoons. Keep up the great work!
So cool! Would really give funds for your research. If I would have...I WOULD...definitely! No doubt! Hopefully people will! However...I'll self-fund mine. Biology is as important as discovering the "skies". Awesome work! AWESOME! My passion since I was a child has always been reaching for the stars. Knowing what's out there! I'll work consistently, as much as I can...not to reach for the stars, but to try to extend human lifespan..so then to reach for the starts. Reaching for the stars is the ultimate GOAL! Congrats on your work! Columbia University rockz!!
Good question! I think you’re sort of imagining that universe is 13.8 Gyr old and we can only exist if that’s that old and no older. Of course we could emerge whenever in the universe (so long as we have habitable conditions) so the setup here is somewhat misplaced
@@CoolWorldsLab I really appreciate your prompt reply, I am aware of the fairly recent doubt cast upon the age of the universe but we exist now and life which evolves in the future is beyond our ability to predict or interact with. Feel a bit stupid, like I'm missing something that should be obvious :)
I was a little confused by this being a layperson and all - although M Dwarves might live 20 x longer eventually, they may only have been around for say 5 x longer so far? So it might be that we are just talking 5 x 5 rather than 5 x 20 which is a fair difference...
@@krest2848 My friend, I'm still confused. Given that our solar system is roughly one third the age of the universe and that life couldn't have developed around population II stars, surely the only factor worth considering is that M Dwarves are more abundant? Not their slower fusion rate.
@@krest2848 I'm glad I'm not crazy and someone else in the comments came to this realization! If we took the logic at 3:29 to the extreme and said that M-Dwarves live forever, they would be infinitely more likely to support life even though the universe is only ~13 billion years old. This is unless he meant that M-Dwarves *have* existed on average 20 times longer than our type of star.
Why are we born as humans? There are so many other species around, that the odds are that we would have been born as ... well as an insect, because insects are the most common species on earth. What do I want to say: Red dwarf stars are much more common, but that doesn't mean, that we must live around one.
While your conclusion is arguable but your analogy misses the mark. You weren't "born human" so much as you developed the cognitive ability to recognise you are human. You are (or appear to be) externalising your sense of self (mind, spirit, what have you) and assuming it is in some way transferable. You (your sense of 'you' anyway) did not exist before you body and you will cease to exist after it, assuming of course that we ignore any theological or spiritual beliefs (i.e. afterlife, reincarnation etc). A better analogy for your point might be something along the principle of- 'just because you have a billion options does not mean you won't fall into the most unexpected one'. This point that you are making was his very first point in the video as well mind you; so I suspect without realising it you have resonated with the first possible explanation to the question: it just so happened the way that it did. Not having a go; just providing some alternative insight.
While some of the other solutions may modify the liklihood, you could always reintroduce the paradox by making the premises more specific. For instance by only including G type stars, or in an a very tight brightness range. At some point you will trigger Resolution 1 because you are only born in one very specific place. Consider, Why was I not born outside of Europe/United Kingdom/Scotland/Glasgow/Specific hospital?
yeah, that's exactly what I thought. Most people on Earth live in Asia, but still a lot of us were born in villages or small towns that are tens of thousands less likely than Pekin, for example
Resolution 2 is the one that I immediately thought of, because red dwarfs tend to send out a lot more flares and the habitable zones tend to be a lot closer to the stars and habitable planets are thus more vulnerable to those flares.
Despite almost endless life of the M-dwarfs, planets in this environment has a strong limitation. You see, the life can emerge only in geologicaly active planet {plate tectonics}. But no planet can be active more than 6-8 bln yrs. The metal core, which produce a magnetic field is inevitably freeze and a planet die...
That’s a great suggestion and one a couple of colleagues discussed with me too whilst working on this. A couple of issues are that first we don’t really know how long planets can remain geologically active, super Earths may last far longer for example. Nor is it clear to what degree this is crucial for life. Second, this doesn’t really explain why Ms are less habitable than FGKs, although it would certainly attenuate the temporal advantage effect.
My thought too. The 10 billion year half life of Thorium 232 should keep a planet geologically active longer than 6-8 billion years, but not orders of magnitude longer. The trillion year lifetime of the star doesn't help.
@@jimbaerg1100 I agree with you, but don't forget -- before 2-3 of bln yrs Thorium will decay, the convection in mantle will ceased. So, continents will stop moving. And then a metal liquid core gets so thick, that magnetic field will disappear. All of this means -- the planet is dead!
If I learned that life can't arise on planets orbiting M type stars.....I'm not going to be surprised. If I learned that life can't arise on planets which don't have large moons.....I'm not going to be surprised. If I learned that life can't arise on planets tidally locked to their suns.......I'm not going to be surprised. I can keep going on and on. Life being rare and apparently not existent in the rest of the galaxy is not a paradox to me anymore than seeing the Power Ball jackpot climb past 1 billion dollars is. A lot of tickets were sold and somebody "should have won already" but sometimes strange shit happens. Maybe we are the strange shit,
That's my thinking, and the only thing that makes sense. Life can only arise on the absolute singular conditions of our planet, with our sun, our moon, our orbit, our position in space and time. Any single alteration to these conditions and life does not arise.
@@Arvandor81 So you (we really) are the chosen one, it "make sense" as it's the safest way to think about it, also kind of gives you (us) that very nice sense of pride/accomplishment, "We are IT, and only we!" For all we know you might be right, but I see it as likely as that the universe is really infinte and as such has infinte versions of Earth and infinte Earth itself, on each of the exact same infinite versions of Earth, there's the exact same you and me, and they (we?) are typing in the comments of yet another amazing video from Prof. Kipping.
@@demonbox7780 I disagree with Kipping about the consequences of an infinite universe. Consider this thought experiment. Imagine a very large bin holding balls. The bin contains an infinite number of white balls and one black ball. If you were to randomly draw a ball from the bin it is possible you can draw the black ball because the black ball exists. The probability you draw the black ball is zero. After an infinite number of tries is it guaranteed you'd draw the black ball even once? In this thought experiment all the balls in the bin represent the landscape of all possible universes. The single black ball represents this exact universe. The white balls represent all other possible universes that are not this exact universe. The act of drawing a ball is the process by which the multi-verse takes a possible universe and makes it an actual universe. Why is it that infinite possibilities require everything that can happen to happen an infinite number of times? Why can't certain configurations of matter occur just once?
@@demonbox7780 Perhaps, but as another science video I watched recently pointed out, belief in an infinite universe is not falsifiable, and thus is not scientific.
@@richmigala2539 Because give infinte chances (both spatially and temporally), and also that one black ball will be infinite, so you'll eventually end up draw it out an infinte amount of times. I do not personally believe that's the "configuration" of the universe btw, just stated that from my very ingorant point of view is as likely, if not more likely than, life only happened and will only happen on Earth. Using the ball analogy, at this very moment we are in a situation where, we blindly picked one ball out of a bin containing trillions of balls, we touched them so we know there are A LOT, just don't know how many and what they actually look like and contain. That ball is the Solar system, we opened it and inside there are 9 smaller balls, our star and planets, out of these smaller balls we are pretty confident only 1 has at it's core the elements to create life, but we haven't had a chance to open the remining 7 balls so can't be 100% sure. Now how can we confidently say that's the ONLY ball who could muster life in the whole bin?
Besides for what was mentioned in the video, there's another problem with using a 20x multiplicative factor of how likely it should be to find ourselves living around a red dwarf. So ok, on average red dwarf stars live 20x longer than sun-like stars. However the universe is extremely young, I believe it's not even 14 billion years old, i think it's like 13.7 billion years. From what I could find, a sun like star (specifically G2, which admittedly is more narrow than the range of "sun-like" stars used in the video, but that's the classification of the sun) will fuse hydrogen (be in the main sequence phase of life) for about 10 billion years. That is over 70% the age of the universe. There just hasn't been enough time for sun like stars to be born and die and go through multiple generations for the 20x longer lifespan of red dwarfs to contribute to the likelihood of finding us (or any civilization) living around them by anywhere close to 20x. Sure red dwarves may live 20x longer on average, but there hasn't even been enough time for 1.5 generations of sun like stars to be born and die, let alone 20 generations.
We need more scientific papers like the one discussed here. If someone can write about a statistical uncertainty and get published. Then so many more ideas can be brought to life with solid research that any journal browsing can supply information for. I like the guy before this video, but now I can enjoy it as well.
The more I watch, the more curious I become about the universe. I am a medical student who is deeply bonded into Astro and theoretical physics, love your work.
@@JustinOhio But do ask if red-dwarf systems are unlikely to gestate life not only because of hostile stellar conditions , but because the Earth-like planets age and die .
I would like to add a thought to solution III: The significance of the longevity of red dwarfs may depend on the point of time at which our galaxy and our neighborhood within that galaxy became friendly to complex life. If it was very active in the beginning - e.g. many supernovas, many quasar jets or other radiation events - evolution of complex life on early red dwarfs would be been difficult. And red dwarfs which were born before lots of the more heavy elements emerging from such supernovas arrived could miss some of ingredients fostering the evolution of complex life. So the early red dwarfs in general would not be good targets for the search for life. Maybe it is even only "our" generation of stars (meaning stars with roughly the same age as our sun) which we should target - and then it is only the quantity, not the longevity of red dwarfs in this generation we should incorporate in our calculations.
Were red dwarfs common in the early universe (12-13bill yrs ago) ? Or did they only become the most abundant type of star later in its evolution, say 5-10billion yrs ago? Curious to know, as it would have certain implications to the paradox as noted above... ie that red dwarfs born early in the universe's history would be poor candidates for finding life as they wouldn't have the necessary ingredients. Wonder if there exists a population iii red dwarf somewhere out there?
And then you can further reduce the quantity of red dwarfs as relevant because they suffer a lot more negatives for the evolution of complex (key word here) life. Tidal locking, solar flares, many factors that red dwarfs are more likely to experience than yellow stars because of the proximity of their Goldilocks zone. Could life still evolve in those conditions? Absolutely. But they’re very harsh to the evolution of _complex_ life. So the fact that we, complex life, find ourselves around a yellow star at a calm and safe distance rather than around a red dwarf as we get bombarded with solar winds and coronal ejections is not really a paradox anymore
My question is, are we asking the right questions? "Where is everybody?" assumes life intelligent enough to generate techno-signatures. I can imagine, given enough time, life being everywhere that there is the energy and chemicals to support it. Maybe looking at types of stars and (our definition of) habitable zones is not going to solve anything. Perhaps life is everywhere, and the real question is what leads life to the intelligence necessary to generate those techno-signatures. There was clearly some evolutionary pressure for our ancestors to develop the intelligence to understand counting numbers and being able to communicate that concept to others. Apex predators don't need to count, vegetarians with no predators don't need to count. Well, not beyond six or seven anyway. I've picked counting only as an example, I don't know what would have been important. Maybe our specialness is not about our sun or our planet, but the very specific conditions that made it so intelligence would be a SIGNIFICANT evolutionary advantage. Without those conditions in our past we would be sitting in trees, perhaps even rulers over the carnivores of the Earth with sticks and stones. But we're not throwing sticks and stones at lions and tigers, we're here at our computers thinking and communicating these very abstract thoughts. As far as I can find, we, collectively still don't really know how our ancestors made that leap. Julian Jaynes has some interesting ideas on what might have happened after that leap, but not what the evolutionary pressure was that took our brains up to that point.
Interesting there is speculation that a gamma ray burst causes the evolution of human. A cosmic event causes prolonged droughts in Africa forcing homonids to travel long distances too find food. This favors the smartest to survive because making the wrong decisions on where to go leads to starvation.
@@kazedcat I think the real answer is way more complex and involves the evolution of human conciousness. I do not believe that intelligence resulted soley from the need for survival. I believe true intelligence arose from the expansion of conciousness/self awareness. Self awareness is actually detrimental to instincts and survival and takes a back seat in a fight or flight situation. Conciousness and intelligence is something that arises after basic survival needs are taken care of. We could go one step further and consider that there are different forms of intelligence, being logical intelligence, and the other being emotional / creative intelligence. The right / left brain paradigm. One is derived from the need for practicality whilst the other is derived from introspection and self awareness. Intelligence that brings about any real advancement encompases both.
But the answer could also be a lot simpler; we do not yet know the length of time a civilisation will 'live', especially through its growing technological phase. Perhaps many civilisations have already existed on other planets and perished. Perhaps they did not escape their dying planets. Perhaps they wiped each other out before space travel, you get the idea. The rate we are going we aren't far enough away from such a fate ourselves.
@@qwert_au Statistically improbable. Not only that, most arguments that touch on technology are tainted with bias and assumptions. Realistically our current level of advancement is extremely low to what it could be. Just another 1000 years of advancement there is an extreme probability that not only will we be colonising our solar system but also managing intersteller and intergalactic travel. It also hinges off the assumption that we will wipe ourselves out within the next 1000 years which is extremely pesimistic and partly a result of our inherent nature to catastrophise everything.
First time watching your channel, just found it with this video. Great production here and fascinating subject matter. Definitely a well earned subscription!
Fascinating...I'll give, in my opinion, the very best compliment I can. Your video's always make me think and give me a desire to go learn more, as much as I can on the subject. This video does that like almost all your videos do. Thx 4 the upload
"Red Sky" is not a paradox. Labeling it a paradox diminishes the significance of the word. It's kind of like saying "It's a paradox I was not born in Asia; there are far more people in that region, so how did I end up being born in North America?"
Honestly your probability theory on intelligent life was accurate to my own theories. What counts as intelligent life is still debated on, but I still give life a high probability. When I found out about tons of life around volcanoes underwater, I grew a lot more curious about how life truly works. I agree that there simply isn't enough information out there yet. Having said that, I'm truly excited to see what James Webb discovers. I feel like it's going to do a lot of interesting things to change our perception of the universe. I love Hubble, but I'm stoic for what James Webb will do. Also if/when Starship launches, it will be a lot easier getting even better satellites than even James Webb. What is important though is James Webb. I've studied a lot about astrologists and reasonable theories and some felt off. I respect their work because it kept us thinking, but already JW has challenged them as well. With complete regard to M stars having life, it's impossible to truly predict accurately. The best thing I can think of is looking for a specific one to try and study more thoroughly than Hubble. There is a lot of data in contradictory to what we're figuring out in months with the JW satellite. I'm excited, even if it's bad news.
Thank you so much for your uploads. It's extremely refreshing to be given well thought-out facts that aren't accompanied with a presenter who also tries to be a comedian to retain my attention... My attention (and probably most people's who enjoy videos like this) is retained by your format.
M-dwarf spectra are similar to incandescent light bulbs. Plants can survive under that light, but not very well. There's just not enough blue for them to thrive. That said, plants on Earth are adapted to use white G-class daylight, not orange M-class daylight.
I very much so hope that the first life we do find is on a planet that we would never expect life to be on such as a gas planet just to prove to humanity that we are being too closed minded about how life can form.
I love this channel, it’s got the same kind of flair and standards as David Attenborough or even Brian cox, gives us so much info but leaves us questioning even more, coming away from this channel leaves you in awe of the universe a little more each time
It being a coincidence is plenty satisfying an explanation for me... the amount of coincidences and cosmic flukes that surround us at all times is astounding. As I see it, it isn't at all difficult to add one more to the list.
I have also seen studies suggesting that ultraviolet light is crucial in creating/evolving RNA like molecules. Red dwarfs just don't have as much ultraviolet light.
This was also my immediate question about the likelihood of lifeforms not only being created in the first place, but having enough of the right amount and type of radiation to continue to evolve and ultimately survive across the number of generations it would take to become complex organisms. The initial creation of life could possibly happen all the time in these habitable worlds, but they simply don't survive long enough to become intelligent. This paradox asks why we, as the infinitely complex organisms that the human species has become, did not emerge on a planet orbiting a red star. Well, we are only able to survive the amount of ultraviolet radiation that we receive from the sun because of the ozone layer of our atmosphere shielding us and bringing the amount of radiation down to a level that is tolerable for not only us, but that feeds the plantlife that sustains the animals we prey upon. However, this amount of radiation is also something of a 'goldilocks' attribute of our planet, because it also not too low. Too little radiation, and the plantlife would not be able to generate enough energy through photosynthesis. So ultimately, the problem of proper radiation exposure is one that occurs repeatedly along the temporal scale for the potential of producing intelligent life. All of the elements have to be just right, and that lessens the possibility of it occurring even more.
Universe is still very young so the longevity part can be thrown out of the equation for now. I believe that with our current knowledge it’s extremely egocentric to call our sun not being a red dwarf a paradox/logical contradiction. Assuming that red dwarf systems are much more habitable then for all we know there might be a lot more, even hundred times more red dwarf star systems with life than there are yellow dwarf star systems with life. If the equations in this video are true then this would mean that ratio is as expected and we are just ones on the smaller side of that ratio. So just because our earth is located in this particular star system type does not create a universe paradox, at least not as far as we know yet with our current tech.
Yes. I came here to say this same thing. Additionally, our sun is a third generation star. First generation stars would have only had hydrogen to work with. Therefore no rocky planets could have existed (I think some helium and even lithium is speculated to have been generated during the big bang, but my point stands). This means that first generation red dwarves would have had no life just like first generation suns like ours. In fact I just found an article that says that the first generation of stars were probably all very large. The downside of this is that the stars probably burned out over the course of millions of years and therefore generation 2 would have been over 13 billion years ago already. Second generation stars would have had more heavy elements. But is is possible here that the number of heavier elements would have been lower. This may have allowed life to form, but it is possible that advanced civilizations could not have come about. I'm just speculating a bit here because I haven't ever found a clear explanation of the generations of stars, even with the article I'm mentioning. The likelihood of red dwarves forming during this time period would have been higher, but we can likely ignore these stars. The article I was reading said that it is possible that "2nd generation stars" could still be forming today. Third generation stars, like our sun, apparently come after these first two generations, but it sounds like, from the article, that they actually could be many generations later, we just can't really tell the difference once we get this far in. But if we assume that advanced civilization must come from third generation stars, then that limits the amount of time that the universe has been capable of generating suns that, in turn, have been capable of generation advanced civilizations. Add to that the fact that it takes time for the suns to collect their elements which means there could be millions or even billions of years between the death of one generation of star till the next generation is capable of coming together. Then the fact that the planets take time to coalesce as well. It also sounds like, based upon other websites I found, that red dwarves take longer to become stable. In the end, the amount of time red dwarves have had to foster life that could evolve into intelligent species which could, in turn, harbor advanced civilizations might not be any longer than our sun has been around. In other words, it is my opinion that the longevity of red dwarves actually works against them. There might be more, but the older they are the less likely they are of being capable of creating advanced civilizations. We could ask this question reasonably in 50 billion years, but at this time in the history of the universe, suns like ours might be the only places that advanced civilizations COULD form.
The intensity with which you work, evident from your published papers, is inspirational. I look up to you and your videos for that among other highly intriguing astrophysical material.
Everything i've researched on the subject seems to indicate that m class starts aren't particularly suitable for complex life, k class stars seems like a better option to focus on.
But as the universe is only 13.8 billion years old, the longevity of red dwarfs won't come into calculation as we are making observation at the age of 13.8 B and not 100 T. So, the chance will be 1 to 5 and this explains coincidence. Please correct me if I am wrong.
Well, I’d probably toss that honor to mathematics, from whose womb came physics and chemistry, high-achieving and well-behaved, respectively, and followed by engineering, off to war again, and of course, geology, with his head in the sand, and biology, evolution, anthropology and medicine perennially too young to worry about the future. But they’re all darlings, to a fault. (Not a bit like their father, thank god.)
What so many people don't seem to TRULY understand, is for us here on Earth, life and all that it is has little to do with the star other than that the sun is a handy source of energy - but not until life here learned how to utilize it. There is some ongoing cutting edge studies which is shining light on the growing, mounting probability that terrestrial life is FAR more deeply connected to THIS planet than we generally conceive. Which is to say that the physical syntax allowing us to be here is of a very different order than the thought, logic, and linguistic syntax we have been using to try and apprehend the circumstances of life here. Put overly simply, and from a different angle, and perspective, we don't live on a star. We live on a Planet which we are part of. This planet like ALL planets is involved in a very complex intercourse with many MANY factors, chemically, electromagnetically, quantum mechanically, just to name the tip of the iceberg - And like all planets and stars our situation is very unique, and one of a kind. I would stake anything on a wager that we will come to realize this the very hard way if at ALL. So to me there is no paradox, and no surprise concerning our star. Microbes out number humans millions to one and they have and will for as long as life exists during which time human form has been only one fraction of an eyeblink compared to a full lifespan - why was I born as the human I am? Yet we must realize that We too have likely been around for millions perhaps billions of years in various forms as adaptation and evolution shaped and reshaped our form and species, until finally going for broke here we are at the brink of extinction and too stupid to accept our stupidity may very well prove far more formidable a foe than all other existential threats we know of combined and X 10. I AM being optimistic and positive. Things are a lot worse these days than almost everyone may think. Unfortunately. If we live out our natural lifespans - those alive NOW - it will be a fucking miracle, and realistically about as much as we should expect in ANY event.
As a kid I remember "Pinocchio's paradox," which starts with Pinocchio saying, "my nose will grow now..." If you're not familiar with it, let that statement sink in, and let the imagination run with it.❤😃
We're looking at habitable zone and stable star, but we should be looking at shielding Jupiter and a stabilizing moon as well, if we ever think about finding complex lives in exoplanets.
Yeah, but these are just Earth based, human philosophies. I mean Jupiter may shield us from SOME things, but space is HUUUUGE. Global killing asteroids can come from SOOOO MANY angles in space, that even Jupiter can't block them all. And having a stabilizing moon. Sure, but more Earth based assumptions. Human life may have done just fine even without the moon being apart of our system. There's just no way to prove tha the moon guarantees us any better successful survival and evolution than being without one. Being in the sun's Goldilocks zone is 99% of the reason why Earth has life on it.
@@blackSUAAAVE i'd disagree with certain points. In my opinion when it comes to probability, proximity to projectiles increases the odds of it teaching us so most of near earth object usually originate from oort cloud or from asteroid belt rather than from outside solar system so i still feel Jupiter plays a major role in reducing mass extinction asteroid event though that's not fool proof, we've had many mass extinctions in past to explain that. I'll rephrase my thoughts about moon, a planet with a stable rotary axis is needed for complex lives to evolve, for us it's provided by moon, (for exoplanets it's very difficult to bet on its axis) constant shift of axis will destabilize life from evolving to complex forms.
@@MrDocAKS - Yeah, but we don't have examples of 'almost life...but they didn't have a moon' planetary systems out there. Sure, it a bunch of Earth like planets were out there, but were barren because they just couldn't quite get the same things we have here on Earth...YES. I would buy the idea that a moon is necessary for life as we know it. If a planet sits in the Goldilocks zone of a stable star, and that planet has liquid water, a magnetic core, an atmosphere, has seasons, it's going to have some form of life on it. Jupiter doesn't even cover 1% of the sky, so how can it be this guardian angel that's keeping Earth protected like a rugged bouncer at a night club? I'm not saying space isn't violent and chaotic. It is, but that's early stages of solar system formation stuff. Once it reaches a point of measurable stabilization, i.e. 2-3 billion years or so into forming itself, all the planetary bombardment of celestial bodies really thin out. Orbits stabilize, the planets 'clean up' around themselves, i.e. pull in or eject smaller bodies around them. Once they clean up, they start to...improve, and evolve. There is life out there in the universe. We humans are just not advanced enough to discover it yet. Some planets only have plant life on it. Some planets have plants and animals. Some have plants, animals, aquatic animals, and yes...sentient beings. Whether or not all of these sentient planets have moons or not is immaterial. There's more than one way to have life on a planet. Having a moon is only one way for it to happen.
I guess I don't understand what the longevity of red dwarves has to do with the emergence of life at this point in our universe's existence. If we were somehow looking backward at the end of time, long after all the stars had burned out, and THEN we found that life only emerged on this one Yellow dwarf star that burnt out 1000x faster than it's red dwarf counterparts, then we could say in retrospect, perhaps longevity isn't a factor. But right now, Universe = 13.5 y/o give or take, Sun/Earth = 4.5 billion y/o give or take, Bernard's star = 10 billion y/o give or take, Alpha Centauri 5 billion y/o give or take. 5 billion years is nothing to sneeze at, but in the grand scheme of things EVERY star that has ever existed, even those that have collapsed or exploded was/is a baby compared to how old these baby red dwarves will become. It's sort of like putting Mozart next to a million other 8 year olds and wonder why the only musical prodigy was born in Vienna.
Another gem of a video. You really do 'hit the nail on the head' with these. Even the 'ads/sponsor thanks' are relevant. The comments below are thought provoking too. It is great the way you avoid lurid speculation/cheap sensationalism and present statistics and astronomy in a way that is far more fascinating than science fiction. Keep going!
I think you overestimated the time advantage of M stars given that the current age of the universe is only 13.8 billion years old. When factoring that in, the time advantage of M stars only gives about 2x the advantage in frequency at the current time, but will grow through time. When factoring this in I think you're only talking about 90-10 advantage for life around M stars, which is significant, but not crazy odds.
Our sun is a third generation star if I remember correctly, which means we have all those heavier elements created in previous supernovas as building blocks from when earth formed. Considering life here on earth is contingent upon having a big variety of chemical elements, perhaps life has a much harder time - or simply cannot - form around a “first generation” star, because there aren’t enough of those needed elemental building stones in the protoplanetary cloud? If an m-dwarf star can live much longer, perhaps many of them are still these old “first generation” stars, whose planets are thus created from this first protoplanetary disk, before any supernova has occurred. This would mean that those planets don’t have enough of those metals and heavier matter that can only be created in supernovas. If this is indeed the case, that “first generation” stars cannot have life, then perhaps the apparent abundance of red dwarves caused by their longevity is actually to the red dwarves’ _disadvantage_ when it comes to creating life. I imagine this would mean that the amount of red dwarves that actually have suitable rocky planets aren’t as abundant as our initial sample size suggests, if many or all of the first-generation (and perhaps also second-generation) stars can be discounted. Is this a reasonable conclusion, professor David, or is there something fundamental that I’m missing? 😅
Im so intrigued by astronomy and alike. Your videos are awesome i love it. Its literally like crack. Keep up the videos man ive gotten through so many rough times with these astrological videos its unreal. Thank you
I have been evangelizing your videos to all my friends and forcing them on my boyfriend. I love exploring concepts related to the universe, it's what got me into physics and engineering. The Cool Worlds channel is the single best science channel out there. P.S. can you put out the background music for purchase or on something like Spotify? I'd love to listen to it at work while coding/problem solving. Thanks professor Kipling! Keep up the awesome work.
There's one aspect that is rarely discussed and seems to me like a major factor but it may as well be that I just don't understand the problem behind Fermi's paradox. So, why do you expect to see any alien life right now in the first place? We barely can pick up shadows of a small fraction of planets orbiting other stars. Or is it that people's expectations of alien life got skewed by SciFi so much that they get cranky for not seeing death stars zooming around, chasing Enterprise type vessels. I guess we (humans) are so damn important, we're waiting for that official invitation to the galactic federation. All that while we still fail to apply realisting expectations to the current state of knowledge according to which interstellar travel is nearly impossible (for humans at least). Currently the best and fastest known way of information propagation is with c and if you travelled out 100 lyrs out with the best realistically sized antenna would you be able to receive, recognize and understand early human radio signals? I think there's the step 1 of answering the question and only when we actually gain data coverage we can consider paradoxes within.
Isn't the biggest problem the fact that most planets in red dwarf systems in there habitable zone are tidally locked to their star? As stars get bigger, the habitable zone grows so less of a chance for tidal locking. Tidal locking doesn't preclude the development of life, but it does make it harder for complex life to develop. When we say "life" don't we really mean life with advanced civilizations capable of space travel? It's not that scientists wouldn't love to study a planet with green goo life on it, but that's not what we are really wanting to find. If it hadn't been for a timely asteroid impact, earth would still be a dinosaur planet. Our large moon gave us seasons. That may or may not be a big reason for the development of advanced civilizations. Even if intelligent life develops, how often does it get stuck at some low technological level? If it does develop advanced technology, how often does it destroy itself due to war or accident? Also, how often do cosmic events and asteroid impacts require life to start over? Finally, we may just be the first ones. In order for our complex biology to happen star had to live and die many times to produce all the elements we take for granted. As this video explains, it may just be too soon for life to develop around most smaller stars.
David breaks everything down into common sense and awareness, he has really opened my mind to all possibilities. Thank you Cool Worlds Lab for all you do!!!!!
This channel is just wonderful. After 2-3 years out of university i am reading a scientific paper again (at 11pm on a thursday). Even thou i studied social science, the cosmos and astronomy is still my favorit subject since my childhood. Thank you CoolLabs and Prof. Kipping! It is truly a joy to watch your videos
First of all, love your channel! Thanks for the great content; it's super accessible and digestible! I'm a bit confused on an aspect of the red sky paradox and was wondering if you could help clarify my thinking. Since the universe is roughly 14 billion years old, I'm inclined to think the difference in lifespan between Sun-like stars and M-dwarfs has no effect on the probability of finding life around either of these two types of stars at this point in time in the universe (since the time advantage of M-dwarfs hasn't kicked in yet). This leads me to the following questions: 1. For any life that happens to exist in this period, would the chances of existing around a Sun-like start fall back to 1 in 5? 2. Would this viewpoint then reframe the paradox to more of "why do we exist this early in the universe?" rather than "why do we live around a Sun-like star"?
Thanks for watching. The current age of the universe is only relevant if you assume that civilizations can only emerge in times ranging from the Big Bang until now, if they can emerge whenever in cosmic history then this dissolves. Great question though!
@@CoolWorldsLab Thanks, that helped provoke some thoughts that let to me figuring out where my confusion lies (although it's taken me quite a while to actually figure it out, and please correct me if I'm wrong at all). So most of the video is spent drawing conclusions about the topic of civilizations emerging at any time in the Universe. The end of the video uses the conclusions to help decide where future life-hunting telescopes should be pointed. However, if we are searching for life, we can only look at the present and past, which should then mean the age of the universe is relevant, and the civilizations we are looking for are equally likely on Sun-like stars and M-dwarfs.
I think you are correct that it would revert to 1 in 5 If it is taken as a given that the universe is 14 billion years old. This, however is not the assumption, as when we find ourselves in the universe, one looks at the universe's entire history as the substrate for the relative probability of our existence. Mind bending and counterintuitive to be sure.
@@CoolWorldsLab Assuming that civilizations can only emerge in a small window of time is correct. We exist now, not in the future. What counts is the conditions now. (And not too far in the past either, time was needed to build enough heavy elements). Imagine you are an early human, 200,000 years ago, living in Ethiopia. You wonder why you are living in Ethiopia, given that the vast majority of people who will ever live, will live somewhere other than Ethiopia. It's because, at the time, everyone lived in Ethiopia. You might be able to wonder why you are living at the *time* you are living, but the question of the *place* you are living is already answered. And wondering why you are living *when* you are living is just the ancient question of "why am I me, rather than somebody else." This is not really answerable, and certainly isn't scientific.
I cannot believe the quality of the content that David uploads. And not only is the quality beyond amazing, the channel is also consistent with its uploads. And people wonder why less and less of us watch tv. There's no tv station that offers content this incredible.
You failed to mention that red dwarfs planents in their habitable zones have orbits that result in planents being tidally locked. This, along with the heavy radiation flares and coronal mass ejections (CMEs) associated with red dwarfs are serious factors in regards to intelligent life arising around this star class. The tidal locking means no protective magnetophere from any cosmic radiation, including the additional radiation exposure from cosmic rays.
Potential resolution: The fermi paradox and red sky paradox both account for the statistical probability of life by examining planets conisdered within a habitable zone. It would seem they do not account for the likelihood that human level inteligence would form. Could it be possible that the earth exists within a zone where life is possible but also that life is exposed to such high levels of mutagenic radiation that evolution and mutation becomes accelerated. A potential solution to the fermi and red sky paradox is that human level intelligence is very uncommon due to a very strict celestial circumstance that allows intelligence to form within a fast enough time scale. Its not unlikely for intelligent life to develop around m dwarfs, we were just early to the party.
You guys are really smart. In a funny way. You are creative, and funny enough this lets you make a new step in physics. Discovering statistical possibilities of living planets in a galaxy. Exciting!! :)
I never really understood the argument of "how can we be here if it's so unlikely". Let me demonstrate that with lottery: the chances of winning a lottery are 1 in... a lot. Several millions? Let's say a million. This means that no one has a real chance of winning... yet someone always wins. We won the "yellow star lottery", unlikely as it may be.
If we are to apply Fermi paradox to ourselves. Wouldn't it make more sense why our star is a yellow star? As in we beat the odds in comparison to "possible" intelligent life forms emerging. I feel like sometimes simple answers to intuitive questions fairs best.
This doesn't factor into the Red Sky Paradox, but I have also been fascniated by the sheer luck that we live at the perfect time on Earth that the moon and sun are the same apparent size in our sky, despite the sun being millions of times larger than our moon. And because of that we can witness a total solar eclipse, on our own planet.
Thanks so much for watching everybody, and thanks to our sponsor - head to www.Brilliant.org/CoolWorlds to learn more! Let me know down below which resolution you prefer, and if there are any other apparent cosmic paradoxes that keep *you* awake at night?
You content is like the old school stuff you'd find in the late 90s on the learning or discovery Channel before they found reality TV!
Haha thanks!
as always, your videos make me regret not studying astrophysics at university... you are one of my favourite scientists in the world! love your story-telling style
I thought our star was white, not yellow.
The Sun is indeed white if viewed in space, but when we view it usually appears yellow due to several effects, I didn’t really want to get into the nuance of this as it’s mostly irrelevant to the video so we’ll just stick with the colour most people see!! (I posted a more detailed explanation about this as a separate comment)
You can't even imagine how many times I have refered to your videos while discussing the universe with people (sober or not). Cool Worlds has become my favourite channel and made me even more interested in the universe and everything about it!
So many of the best conversations about the universe happen with friends!
Always not sober, at least for me
@@CoolWorldsLab Indeed
@@WildZeratul I can relate
Can you guys clarify if our sun is white or yellow?
when I was young, I was enthralled to sit and listen to Carl Sagan for hours. Now there is David Kipping to take his place and enthrall my sense of intrigue and wonderment. Keep up the good work David
Right❤️
👏👏
I feel like the most fortunate person just to have exposure to both of these incredible gents during my lifetime 😁
A perfect post. Well said. 1,000 applause.
Yep. Totally Sagan reincarnate. It's something in the voice, mannerisms, presentation, wording, structure...je ne sais quoi. Calm, clear and therapeutic. Only some have it by sheer luck and it can't be faked. Needs to go mainstream badly and replace that dirty manc accent of cox on TV.
My guess is that most red dwarf stars' heliospheres are not powerful enough to shield their planets from the highly-energetic interstellar medium. It's probably something like standing underneath an umbrella in a rainstorm as opposed to standing underneath a full roof.
Planets orbiting red dwarfs might be close enough to their star to hold liquid water and maybe even a stable climate, and might even be sufficiently shielded from the interstellar medium. But at that range, those planets are probably close enough to their red dwarf to feel the wrath of its problematic mood swings that red dwarfs are notorious for.
It's also likely that any planet in a red dwarf's 'goldie locks' zone will be tidealy locked to their sun and will have one side always facing the sun.
So basically the Trappist system?
@@Icetea-2000 or Proxima B
True. No need to guess. Habitable zone is not habitable at all.
@@KennethScharf you can live on the pole
My favorite theory is that the red dwarf stars have an equal probability of hosting life with our sun, but that it takes longer for that life to initially emerge. As mentioned, red dwarfs are unstable at the beginning, and the universe is only 13 billion years old. Perhaps yellow stars are simply more conducive to creating life more early in the span of the universe.
I don't think you can have Earth like life around an M star. Maybe simple microbial life, fungus. that's about it.
"The universe is only 13 billion years old." This idea is being challenged, because the Universe is expanding at such a rate that there are parts of the Universe we cannot ever see (from Earth) due to the amount of space being created. Literally, beyond the furthest reaches of the Universe we can see, more space is being added than light can traverse, so the light never reaches us. Thus we have no idea how big our Universe actually is, or how old, since we literally can't see that far back. Remember, when we look up into the sky, we are also looking into the past: we see the moon as it was 1 second ago, the Sun 8 minutes ago, the star Alpha Centauri as it was 4.3 years ago, as it takes that long for light from those objects to reach us. 13 billion years is about how far we can "see" - anything further away, we literally can't see because the light can't reach us. So that 13 billion number is actually a minimum, based on current available observation. The Universe could be 80 trillion years old, for all we know.
Fascinating work, thank you. But how does the age of the universe affect this? It seems to me that considering our earth is about one third the age of the universe, it doesn't matter that red dwarfs can last so much longer than our sun. They only have lasted at most 3 times as long, and on average something like 1.5 times as long. -Adrian in Australia
I had the exact same thought
Even worse, the early red dwarfs (and their possible planets) were formed long before there were heavy elements with which to form planets… and life. In fact, the era when there were significant heavy elements was approximately when the Sun formed. The only stars we should be comparing with are the other stars formed in that era. Lifespan of the red dwarfs is thus irrelevant.
We could be early
@@jursamaj This is exactly right and a well known fact whenever considering life formation. To be more precise we need a high enough density of phosphorus to allow for organic chains. Second there is likely no chance for photosynthesis at infrared (or it would have likely evolved on Earth by now). Third there is a mess with tidal locking and tidal forces
You could think of life span as a fuel tank, the star dies when it runs out of fuel, the ages of these stars are simply calculated by the rate at which they use energy not by direct observation.
And just to answer a common question I’m seeing: isn’t the Sun white? First, the Sun appears yellowish to us when we usually look at it due to a combination of effects such as safe viewing elevations and Rayleigh scattering. So culturally we think of the Sun as yellow. In space it would look closer to white though. A second complication is that when an astronomer says “white dwarf” they’re actually referring to a post main sequence stellar remnant, the Sun is not (yet) a white dwarf so we can’t use that language to describe it because it implies a very different object! For this reason FGKs tend to be referred to as yellow dwarfs (orange for later K types). I didn’t really want to spend too long explaining this in the video because it’s frankly irrelevant to the topic but enough if you asked about this that I wanted to clear it up!
*enough of you
Thank you
Otoh you could just say that "G yellow dwarf" is just the name of the classification. Just like "pink" is the name of a pop star...
NERRRRRRRRRRRRRRRRDDDDD!!!
(Genius Envy)
Am I wrong for thinking all stars would look more or less white because they emit the entire spectrum of visible light, it's just which wavelength is the most prevalent that gives them their "colour"?
My guess is that planets in the Goldilocks zone of red dwarves would be tidal locked (no seasons, no day/night cycle) and would have no or tiny moons (no tides). That's a tough recipe for life, let alone intelligence to emerge.
That would be my resolution... that there is probably simple life but complex life needs another 50 or so billion years on red dwarves
There's also the possibility that planets in the Goldilocks zone would suffer solar winds powerful enough to sterilize surface life such as cyanobacteria.
there could still be tides. look at io
@@weltraumameisenbaer8789 IO's orbit is pretty elliptical and irregular, and the tides are a result of that and the tug of war between Jupiter and the other 3 Galilean moons upon it. By definition, any planet would have cleared its orbit and thus would not have a 3 body problem going on. The orbit would be circular and regular and would not have any other outside influence on it. What you are describing would be something more akin to an asteroid belt body rather than a planet.
right, i havent thought about the other moons. i thought it was just because of excentricity.
Temporal paucity, but the opposite of what you proposed. All red dwarf systems are young now. Even the oldest are barely to 5% of their lifespans. Our system didn't evolve intelligence till our star was at 80% of it's stable lifespan, and red dwarfs take even longer to settle down.
this is my thought also. the solar system is 5~ billion years old in a supposedly 14~ billion year old universe. We are so early to the scene it's not funny. You can't even compare red dwarfs fairly because red dwarfs might live for 100 trillion years but we haven't even come close to that figure yet so their lifespan increase is negligible. I think it's pretty likely that the first 5-10 billion years of the universe were probably more inhospitable for life due to just way more crap going on, so it seems reasonable to me that we could actually be part of the first generation of life. That's not an implication we are the *first* life, just part of the early generations of it, which also explains our loneliness because the light from other early generation life can't reach us yet.
It's all speculation of course, but to me this seems more feasible than not.
@@empty5013 this makes the most sense to me. We exist all as vibrations of crazy ass particles and quarks. We are an example of when things go right for life it will find a way. We mustn’t let the future and possibly other reality frequency vibrating beings out there down!
I was under the impression that these M dwarf stars flare so frequently and the habitable zones are so close, it would either completely strip any atmosphere away and/or cause it to become tidally locked. I thought this made the idea of habitable planets around them to be a complete no-go?
Would an Earth-sized planet with an Earth-equivalent magnetic field be able to stop an M dwarf star from stripping its atmosphere away from such a close orbit?
You found this information, how come a Phd astrophysicist did not? Red dwarf stars have no habitable zone.
@@frankkolmann4801 Not to mention the glaring issue with the 1 percent statistic in the video - while it's true that red dwarf stars have the time advantage with a lifespan of up to trillions of years, Dr. Kipping pointed out in the video that the universe has not even _existed_ for trillions of years, hardly having passed 10 billion years of age. The time advantage that red dwarfs have for evolution hasn't even _had time_ to come into play yet, since most yellow (technically white) dwarfs are still very much alive and in the main sequence.
Again as said in the video, at the current point in the universe, there are only 5 times as many main sequence red dwarfs as yellow dwarfs. This brings the red sky paradox chances back up to 1 in 5 for us at this point in the universe's history, even with all else being equal, making Resolution 1 look much more likely again (although a yellow-sky alien in a trillion years would have much more to think about!)
Then you add in what you and OP said, and suddenly there are even more factors indicating that a red dwarf civilization would not be so likely after all, and might be quite rare indeed... at least, for now.
{{ More below, about additional alien paradoxes related to the red sky paradox}}
That brings up the obvious but lesser "orange sky paradox" questioning why we live around a G type sun-like star instead of an orange K-type, which is the relatively mellow, fairly long-lived halfway point between us and the M-type red dwarfs. These stars are less likely to be turbulent for their home planets than the red dwarves, meaning they might have a slight numbers advantage that isn't cancelled out by their absence of a habitable zone. But again, their time advantage has not yet taken place, so this is not likely to cause a significant gap yet.
And as a way to wrap this whole argument of mine up: We can't make accurate theories about the accuracy of the cosmological principle or the differences between ourselves and aliens, due to our sample size of... us. Unless we're the only aliens in the universe or one among very few, that's not a very good sample size for any study. Which naturally leads into the Fermi Paradox - why _haven't_ we found anyone else?
Well, for all the debating we've done about the Fermi Paradox, many have based their assumptions around a flawed premise - that if aliens were out there, even fairly close and rather loud, we would have already and quite easily picked them up. This is simply not true, not even assuming that they're broadcasting in the right frequencies and with sufficient strength for us to pick them up. Refer to the universal constant that terrorizes sci-fi authors, xenobiology theorists, and rocket scientists everywhere - the speed of light.
The first radio broadcast ever sent by humanity was sent 127 years ago. Naturally, this means it has traveled 127 light-years. Even assuming the weak and muddled signal hasn't dissolved into background static over that distance, it's only reached the closest 6,000 or so stars to us, and if there's an alien race with about the same technology as us 100 light years away that received the signal 20-something years ago and blasted something back, we won't know about it for another 73 years at best! Look at the fact that the Milky Way is about 100,000 light years across, and you realize it'll likely be a different geologic era before we get a reply to something we shot out into the cosmos, and twice as long before we can be sure they've received our message back. Forget deciphering the alien message - it'll be almost as difficult to figure out what WE sent so long ago!
This applies the other way around, too - for us to discover aliens 500 light years away, they have to have shot a signal strong enough to detect, directly at us, 500 years ago. Considering that a signal that strong and focused would be a pretty big task even for us now, that raises the question of just how long ago we really expect aliens to have _had_ such advanced tech, or if that'd be so rare that nobody in range would have developed it yet. This difficulty goes up by orders of magnitude if we ever expect to have a Star Trek future of hopping from planet to planet and meeting a vast variety of different species face-to-face in our travels: such journeys would take thousands of years, and by the time Captain Kirk's ship would have returned, the descendants of his crew could have evolved to become just as alien to us as we were to Neanderthals!
Bro, not all red dwarfs are flare stars! Plus YOU COULD ACTUALLY LIVE IN A FLARE STAR IF YOU HAVE A STRONG MAGNETIC FIELD AND GRAVITY. In fact, red dwarf stars do have a habitable zone uncultured swine.
@@frankkolmann4801 "Red dwarf stars have no habitable zone." That's not entirely true.
The larger the star, the larger the habitable zone, but the shorter the life span of the star. This is why we don't look for intelligent life in blue supergiant systems, because the star itself only lasts for millions of years, not the requisite billions+ for evolution of intelligent life as we know it.
Further, our own Sun is considered a G-type star, technically a "yellow dwarf", one size in range larger from red dwarfs. This is just to put the discussion in perspective.
As covered in this video at 3:24, red dwarf stars have a range of sizes. If we were to go hunting for intelligent life in red dwarf systems, if I were to choose, I would target the larger red dwarfs, closer to the 1/2 the size of the Sun category, rather than the tinier red dwarfs closer to the size of Jupiter. Why? The habitable zone point brought up in this thread. The smaller stars _effectively_ have no habitable zone (too small in range that the odds of a planet being placed just right make looking for them almost a fool's errand.) Then there is the additional factor that makes looking for life on such stars moot.
What is that additional factor? As a star ages during its main phase (the longest phase, where it burns hydrogen for energy), its nuclear reaction and heat output goes up to compensate for the increase in helium in its core. Our own Sun is 30% brighter now than it was 5 billion years ago, if I recall correctly. As the energy output increases, so does the habitable zone "range" - but the habitable zone also moves further away from the star. 5 billion years ago, Venus was more ideally placed in the habitable zone as back then the zone was a little closer to the Sun due to the lowered energy output. As of now, Earth is ideally placed. In a red dwarf system (assuming this star is half the size of our Sun as an example), a planet just outside the habitable zone at formation 10 billion years ago might be ideally placed in it today, with life only now starting to thrive on it.
you are likely right see my reply to too cool worlds lab, and the reference that supports exactly what you said. who is likely no Red sky paradox, several publications support that m dwarf exoplanet would require a huge magnetosphere to keep an atmosphere especially in the nearby habitable zone. if we can agree mars never had any intelligent life, what is believed to have had water, and had its atmosphere stripped away, studies CME-solar winds have estimated m dwarf exoplanets require magnetosphere many times earths not to have its atmosphere stripped away like mars.
Great video, as always - but is the time really an important part of the equation (for now) since our universe has "only" a few billions years? And heavier elements are even more recent? I mean, aren't most red sky worlds just as young as Earth?
I was thinking this too. What does it matter if they can last trillions of years? The universe isn't that old yet.
Moreover, I'm a geologist, and I have a running intuition that says that the window for lie to develop on a world is relatively short after it's creation (on a timescale of billions of years). Either the world is going to go snowball and not develop life (in the case of red dwarfs this is even worse, since they are most energetic when young), or it will go hothouse like venus (more common around sunlike stars where the sun's power gradually ramps up). At least in earth's case, it seems that the earth's temperate climate has been stabilised by feedback loops of CO2 and O2 that life itself is responsible for. For Earth, life seems like it was necessary to prevent it turning into a second venus.
RUclips needs more of this, less of the mindless stuff.
How about both? A cat that is scared of cucumbers but can also fart the names of the stars in the sky.
@@Phoenixash-delfuego id watch that all day bruva
@@Phoenixash-delfuego algorithms and payed for advertising 🤦♂️ theres years old vids from people i follow ive never seen but youtube keeps throwing tik tok shite at me lol
How can anyone not find this stuff absolutely facinating???🤔
@@roydoncrerar2852 my thoughts exactly. Too many people nowadays are so addicted to themselves & to the mindless egotistical content of others (esp on social media) that they literally can't see beyond that. Since I was a kid I've always paused in wonder to look up at the moon every time I see it in the sky. Our original Cool World. The only celestial body that we can see as a sphere with details on, & my introduction as a child to the Universe beyond. How many people do that these days? Far too few in my opinion. Channels like this will hopefully change that...
Look, I've played my fair share of XCOM and I can tell you that 99% hit chance miss more than you might think :(
*heavy breathing*
Me: misses 4 99 percent chance shots
Enemy: lands 4 1 percent chances
Love to see notifications from this channel :)
That was quick!!
Samsies
Like others, watching your videos I find myself wondering whether I should have become an astrophysicist instead of a philosopher! Simply wonderful stuff.
The solution for your dilemma is quite simple in my opinion. The spectrum of red dwarf is shifted toward less energetic wavelengths. We all are familiar with the necessity of light to excite reactions and we know that life form began in the sea - well - the spectrum of absorption in the ocean is the lowest around 400nm which is also the heights peak of the sun (the emission of red dwarf is 1000nm - which is almost completely absorbed by the oceans themselves). My assumptions are that in order to create life one needs both a solution (i.e. water which allows for chaotic environment) and an exiting force for interatomic/molecular reactions/interactions - a wavelength around 400nm is equivalent to ~3.1eV which is more than enough to allow for redox reactions as well as band gap excitations.
works for me. To be honest this just seems as a desperate grab for content. This isn't a paradox, it's just a question, a question with what I suspect will be a trivial answer. Case and point the explanation given by Nir Ophek
‘nanometers’ and ‘electron volts’ are not compatible. @Nir Ophek.
The solution is very simple. You need to calculate for god.
We don't "know" that life "began" in the sea. Are you serious with that statement??? There's no evidence whatsoever that life came from non-living material, ever. It's mind boggling where scientists and other people get off saying stuff like that when it's never something that's been observed and there's no evidence for at all. What the hell is wrong with our scientists these days? Abiogenesis is the dumbest thing holding humanity back from actually progressing in our knowledge, it's so ridiculous and frustrating.
@@JustinOhio For you, this is the wrong channel!
Wow I just realized he barely uses any cuts/edits, if any. Usually youtubers have a cut every 5 seconds. Just a naturally talented speaker. Great video as always. Never thought about this question until now, and now I'm intrigued!
He often cuts to a diagram or visual aid while talking. Clever editing can hide a lot of things, but it does seem as though the scripts are incredibly well rehearsed.
Amateurs do 2 takes hahahaha
It’s just the way he produces the video. He puts a lot of cut screens in there. You only see his face during those long segments where he doesn’t cut.
Maybe he just knows what he’s talking about
Well, he does give lectures as a professor and as a speaker so I'm guessing he's used to it. I personally like it better with out cuts even if there is a mistake. It's just RUclips, not an actual TV show in LA or something. lol.
One of social media’s greatest pleasures is seeing Cool Worlds videos say “46 minutes ago”
8 hours ago
12 seconds ago
All of the above ;)
I have actually taken all of Coolworlds videos and joined them all together without the adverts etc, it took a 2 tb drive to do it !.
Could it be that red dwarfs being smaller have habitable zones closer that makes exposition to solar phenomena being hazardous places to develope life (as we know it)?
That was my thinking...and also because of that many planets within the habitable zones of these starts would be tidally locked, making them virtually uninhabitable. Though they say habitability within the "twilight zones" of those planets could be possible, it seems unlikely that life could persevere in such a small sliver of an entire planet.
@@100percentSNAFU I agree with the 2 commenters above..all the radiation, solar eruptions, solar wind, and being tidally locked dont spell out a good chance of life..i.e. proxima b
Life is much more resilient than we tend to think. Even if tidally locked and bombarded with radiation, an underground ocean would be able to host life.
Yes, this video is a joke. Red dwarfs are much more active than our sun, making life harder. And as you said planets would also have to he closer to be in the habitable zone resulting in even more exposure to dangerous radiation. This video was pretty pointless im ngl.
Does he seriously not address this in the video? With a title such as this one I’d assume these basic factors would be looked at. But it seems like (what I’m getting from the comments) is that he went out of his way to present it as much more of a paradox than it is. He even responded to a comment by saying “you make a good point and I have no rebuttal but I’m stubborn so I still don’t agree with you.”
I had always assumed it was widely accepted that red dwarfs were just way to active and due to the proximity between the stars and planets causing tidal locks, no life like ours would be able to evolve.
That or our kind of life simply cannot exist beyond a system like ours.
I've seen a few people respond with this which is what I originally thought aswell. Makes you wonder why this guy would totally ignore this possibility?..
@@himynameis3664 From an optimistic standpoint, he simply ignores it to make the arguments for such a paradox more convincing. From a pessimistic standpoint, his simply trying to click bait people who don't know any better.
@@musicheaven1679 Yeah, after watching the entirety of the vid I think he did kind of mention it but he glossed over it so quick I nearly missed it. And for something that pretty much resolves the "paradox" it shouldn't be glossed over.
The thing that makes me most skeptical about red dwarfs being able to support life is that most red dwarfs’ habitability zone is so close that the planet would be tidally locked and you might only get a ring of temperate conditions between the hot and cold sides. It seems so unlikely to work out just right. However, “eyeball planets” as they are called are really cool to imagine in like a sci-fi setting and I hope I am wrong.
It’s possible some can have a 3:2 resonance like Mercury.
I went camping the other night up in the mountains near Mt. St. Helens in Washington State and thought a lot about the last video about how big the universe is while I was up there. There's nothing quite like staring up in the sky on a clear night with no light pollution and pondering the universe. It's a magical experience.
Our hauntingly beautiful universe
Between the flares and tidally locked planets, I just don’t get the optimism for M dwarfs.
Yup. Both of those look like subtypes of resolution II. I'd have been happier to have the tidal locking problem at least mentioned in the video... I'll be happier about knowing what explanation is plausible when we can at least detect water vapor (or its absence!) in the atmospheres of these worlds (as an index of how bad the flare damage is) and preferably to also detect oxygen.
One other possible resolution to the Fermi paradox as a whole might be from the expected water abundance on superearths. Some of the models predict oceans hundreds of kilometers deep on most of them. Perhaps near-Earth-mass worlds are mostly divided between waterless, lifeless worlds and ocean worlds with plenty of life, but no dry land, or land animals, or technology. Worlds with just the right amount of water to spawn life but also with dry land and fire-wielding technologists might be exceedingly rare.
Red dwarves will, eventually, calm down and flaring will stop. Plenty of them are already pretty timid. In my opinion, it's just too early. In older universe planets around them could boom with life. We are most likely one among the first few odd civilizations in the universe, and also incredibly lucky.
@@Mandrak789 heres a thought experiment. We are refugees of a much older race of beings, a progenitor race that evolved in a much younger universe cast adrift in the universe after their home world/local star cluster expired. This progenitor race had the technology to manipulate the orbits of planets, being directly resposible for tidal locking and sun/moon cycles to create the conditions for us to exist on this planet to their specifications. They then left and continued to seed life in other locations, the only trace of them existing left in ancient structures and myth and our genetics..
@@livinglight9915 ah yes that's one of my fav scenarios, although it must be worked out in details to be believable; lot of plot holes there unfortunatelly
@@Mandrak789 I see conflicting reports on how much red dwarves settle down. E.g. www.universetoday.com/148709/even-older-red-dwarf-stars-are-pumping-out-a-surprising-amount-of-deadly-radiation-at-their-planets/ says Barnard's star, 10-12 billion years old, is still flaring 25% of the time. The other question is, even if the flaring eventually stops, if planets' atmospheres were stripped by the flaring, is there any mechanism to replenish them? Hopefully we'll eventually be able to observe the atmospheres and see what survived or was replenished - or not.
It really pains me when people plug in 20% for the fraction of stars with habitable planets in the Drake Equation given the Red Sky Paradox. Thanks for this brilliant work which sheds direct sunlight (Ha!) on this matter.
If Life can only arise around G type stars then ~7% becomes the upper bound for the fraction of stars with habitable planets. (not an unreasonable assumption). Also...if my aunt had balls she'd be my uncle but she doesn't(as far I know) so she's not.
I think its because those people are afraid to accept the fact that its highly likely they're not the most intelligent species in the Universe. Especially if some of them have the technology to travel through interstellar space in order to come visit us, and observe us as we do animals in the wild or the zoo.
@Smee Self it's equation with so many unknowns it doesn't help... all we've really got are observations
Maybe they should split habitable zone into suitable for life to evolve vs us being already evolved being able to live there. From what i understand brown dwarfs have VERY violent activity. Like way way waaaaaay more violent then our sun.
In fact, if you look all the other solar systems we've discovered so far and compare them to ours, our solar system is STRIKINGLY orderly.
Not saying it was constructed, but if thats what it takes to get life to evolve, then life is probably REALLY rare.
Orange dwarves are where it's at.
Maybe there is something I’m missing here, but haven’t we just not had enough time for this to play out yet? The universe is “only” ~14 billion years old.
How could red stars enjoy a time factor of 20 when there hasn’t been enough time yet for them to outlive stars like the sun (lifespan of about 10 billion years) by that amount?
Excellent video as always, but I'm wondering how the age of the universe factors in. If the universe is only 13.7 billion years old, then why does it matter that red dwarfs can last for trillions of years? It would seem that while the universe is still relatively young, the likelihood of life and civilizations evolving around any type of star with habitable planets would be more or less equal. In half a trillion years there may be far more civilizations around red dwarfs than other stars, but at this stage they haven't had that advantage yet. What am I missing?
I think that when we're talking about the fermi paradox we're talking about why we're seemingly the only life in the universe.
If we're the first planet with intelligent life, and there's an X% chance for life to arise per year, it would stand to reason that there being 5x as many red dwarfs, and their longer life spans make it more likely for any original life developed between now and the end of the universe to find themselves looking up at a red dwarf sun.
So the question is why are we so early to arise here instead of around a red dwarf say a trillion years from now. We could have developed at any point in the future of the universe as well, which is why the long lifetimes of red dwarfs are relevant and might be more likely sources for original life to develop far into the future.
I tend to think we just got lucky and are one of the first intelligent species in the universe, but that there will be many more, and many/most of them will be around red dwarf suns.
Do your solutions take into account the metallicity of stars that form at different points in time in the universe's history? If stars only formed with enough metals to spawn in the last 4 or 5 billion years then it could nullify the time factor for red dwarfs at this point in time, as it would mean red dwarfs with enough metals to form life haven't existed long enough to have a time advantage over M type stars that formed in the same period.
It could be that we are in very early history of civilizations! Perhaps M-dwarf civilizations will happen in 100 billion years!
Yeah, we really are almost as soon as we could have been on a cosmic scale.
The entire universe is barely three times as old as our solar system, and you have to take into account that metals and heavier elements just didn't exist at first.
It's pretty crazy to think about. Life has existed on Earth as soon as it was possible, and an habitable planet like Earth existed as soon as it could.
We are merely wotnessing the dawn of life and civilisation in the universe.
@@leirbag1595 Very excellent points. The Red Sky Paradox doesn't even mention tidal locking (which is huge) and greatly downplays solar flares. So I doubt it considers what you mention, which is something else that likely nullifies it. Sad, but this "paradox" does not appear to be any better than the Drake equation. But, anyway, I've seen and read some really interesting stuff that DO account for the age of stars / presence of metals and when life first began on Earth that do seem to indicate that life began pretty damn quick, pretty much as early as it possibly could have. Which helps towards the case that life may actually be very prevalent in the universe. Now, intelligent life is a totally different thing though - intelligence may be rare even if life is very common. We have no way of knowing how common intelligence is, and probably won't for quite some time.
@@Me__Myself__and__I Multicellular life needed a billion years before it was able to form on Earth, so we will likely only witness intelligent life on planets which are consistently habitable.
Though to address tye solar flares and tidal lockings around red stars, an underground lifeform would be sufficiently protected from the former and might evolve to resist them, and a tidal lock, while unquestionably shitty, leaves an habitable zone with an unending twilight. The conditions on a planet like that would be much more difficult than usual, but given that these worlds would have more time to develop, they might still develop life.
Intelligent life should still be extremely rare, especially human-level intelligence. Goven how long it took for us to appear and how specific our evolutionary path was, most worlds would likely just not recreate them.
Otherwise, yeah there is definitely life out there. Even just in the solar system, there are three other places than Earth that I can think of that ccould be hosting life, plus others which could in the future.
@@leirbag1595 I don't recall the exact details, but multi-cellular life did not take a billion years. Early earth had issues such as asteroid impacts, high temperature, etc. that would have precluded life at the beginning. Once you subtract that time out life took less time to develope.
The thing with Red / M Dwarves is that they haven't really had all that much more time. This video says 20x, but the universe isn't old enough to allow that. Plus, the earlier generations of stars didn't have enough heavy elements available yet. So when you discount the 15x+ time of red dwarves (that hasn't yet occurred) and the earlier timeframe where there weren't yet enough heavy elements - M Dwarves really haven't had much additional time over our star in the present day.
In engineering failure, even catastrophic, 1% is unlikely though not a fluke.
When put on the scale of the galaxy though?
I'll lean to the paucity
Confused how you can consider a factor of 20x longer in life _WHEN THE UNIVERSE HASN'T BEEN AROUND THAT LONG - ??_
Thanks, I wanted to write the same. There is no star in the Universe that is much older than 3 times the age of the sun. The factor of 20x is wrong. I was shocked when he mentioned it.
@@Keymaster Yes, and given what he said about the time to "settle down" of the red dwarfs (dwarves?), the relative advantage may be even less.
excellent point!
He tries to shift the argument and say that you can't limit it to one point in time. Okay, but that demolishes the argument because I can just as easily say you can't limit it to one point in space. If you limit the argument to why present-day humans exist around a G type star, then it has to be PRESENT DAY. He can't have it both ways.
I love how you've been thinking of so many topics in astronomy that others seem to ignore, like red dwarf planet's odds of having life, and exomoons. Keep up the great work!
So cool! Would really give funds for your research. If I would have...I WOULD...definitely! No doubt! Hopefully people will! However...I'll self-fund mine. Biology is as important as discovering the "skies". Awesome work! AWESOME! My passion since I was a child has always been reaching for the stars. Knowing what's out there! I'll work consistently, as much as I can...not to reach for the stars, but to try to extend human lifespan..so then to reach for the starts. Reaching for the stars is the ultimate GOAL! Congrats on your work! Columbia University rockz!!
I'm just an interested, uneducated layperson but is the universe old enough for the longevity of M Dwarves to be a factor?
Good question! I think you’re sort of imagining that universe is 13.8 Gyr old and we can only exist if that’s that old and no older. Of course we could emerge whenever in the universe (so long as we have habitable conditions) so the setup here is somewhat misplaced
@@CoolWorldsLab I really appreciate your prompt reply, I am aware of the fairly recent doubt cast upon the age of the universe but we exist now and life which evolves in the future is beyond our ability to predict or interact with. Feel a bit stupid, like I'm missing something that should be obvious :)
I was a little confused by this being a layperson and all - although M Dwarves might live 20 x longer eventually, they may only have been around for say 5 x longer so far?
So it might be that we are just talking 5 x 5 rather than 5 x 20 which is a fair difference...
@@krest2848 My friend, I'm still confused. Given that our solar system is roughly one third the age of the universe and that life couldn't have developed around population II stars, surely the only factor worth considering is that M Dwarves are more abundant? Not their slower fusion rate.
@@krest2848 I'm glad I'm not crazy and someone else in the comments came to this realization! If we took the logic at 3:29 to the extreme and said that M-Dwarves live forever, they would be infinitely more likely to support life even though the universe is only ~13 billion years old. This is unless he meant that M-Dwarves *have* existed on average 20 times longer than our type of star.
The only thing i didnt like about this video is that it's too short. Prof. Kipping thank you for all these contents you and your team are amazing!
YT likes 10 min videos
Why are we born as humans? There are so many other species around, that the odds are that we would have been born as ... well as an insect, because insects are the most common species on earth.
What do I want to say: Red dwarf stars are much more common, but that doesn't mean, that we must live around one.
While your conclusion is arguable but your analogy misses the mark.
You weren't "born human" so much as you developed the cognitive ability to recognise you are human. You are (or appear to be) externalising your sense of self (mind, spirit, what have you) and assuming it is in some way transferable.
You (your sense of 'you' anyway) did not exist before you body and you will cease to exist after it, assuming of course that we ignore any theological or spiritual beliefs (i.e. afterlife, reincarnation etc).
A better analogy for your point might be something along the principle of- 'just because you have a billion options does not mean you won't fall into the most unexpected one'.
This point that you are making was his very first point in the video as well mind you; so I suspect without realising it you have resonated with the first possible explanation to the question: it just so happened the way that it did.
Not having a go; just providing some alternative insight.
While some of the other solutions may modify the liklihood, you could always reintroduce the paradox by making the premises more specific. For instance by only including G type stars, or in an a very tight brightness range. At some point you will trigger Resolution 1 because you are only born in one very specific place. Consider, Why was I not born outside of Europe/United Kingdom/Scotland/Glasgow/Specific hospital?
yeah, that's exactly what I thought. Most people on Earth live in Asia, but still a lot of us were born in villages or small towns that are tens of thousands less likely than Pekin, for example
Resolution 2 is the one that I immediately thought of, because red dwarfs tend to send out a lot more flares and the habitable zones tend to be a lot closer to the stars and habitable planets are thus more vulnerable to those flares.
Despite almost endless life of the M-dwarfs, planets in this environment has a strong limitation. You see, the life can emerge only in geologicaly active planet {plate tectonics}. But no planet can be active more than 6-8 bln yrs. The metal core, which produce a magnetic field is inevitably freeze and a planet die...
That’s a great suggestion and one a couple of colleagues discussed with me too whilst working on this. A couple of issues are that first we don’t really know how long planets can remain geologically active, super Earths may last far longer for example. Nor is it clear to what degree this is crucial for life. Second, this doesn’t really explain why Ms are less habitable than FGKs, although it would certainly attenuate the temporal advantage effect.
My thought too. The 10 billion year half life of Thorium 232 should keep a planet geologically active longer than 6-8 billion years, but not orders of magnitude longer. The trillion year lifetime of the star doesn't help.
@@jimbaerg1100 I agree with you, but don't forget -- before 2-3 of bln yrs Thorium will decay, the convection in mantle will ceased. So, continents will stop moving. And then a metal liquid core gets so thick, that magnetic field will disappear. All of this means -- the planet is dead!
If I learned that life can't arise on planets orbiting M type stars.....I'm not going to be surprised.
If I learned that life can't arise on planets which don't have large moons.....I'm not going to be surprised.
If I learned that life can't arise on planets tidally locked to their suns.......I'm not going to be surprised.
I can keep going on and on. Life being rare and apparently not existent in the rest of the galaxy is not a paradox to me anymore than seeing the Power Ball jackpot climb past 1 billion dollars is. A lot of tickets were sold and somebody "should have won already" but sometimes strange shit happens. Maybe we are the strange shit,
That's my thinking, and the only thing that makes sense. Life can only arise on the absolute singular conditions of our planet, with our sun, our moon, our orbit, our position in space and time. Any single alteration to these conditions and life does not arise.
@@Arvandor81 So you (we really) are the chosen one, it "make sense" as it's the safest way to think about it, also kind of gives you (us) that very nice sense of pride/accomplishment, "We are IT, and only we!"
For all we know you might be right, but I see it as likely as that the universe is really infinte and as such has infinte versions of Earth and infinte Earth itself, on each of the exact same infinite versions of Earth, there's the exact same you and me, and they (we?) are typing in the comments of yet another amazing video from Prof. Kipping.
@@demonbox7780 I disagree with Kipping about the consequences of an infinite universe. Consider this thought experiment. Imagine a very large bin holding balls. The bin contains an infinite number of white balls and one black ball. If you were to randomly draw a ball from the bin it is possible you can draw the black ball because the black ball exists. The probability you draw the black ball is zero. After an infinite number of tries is it guaranteed you'd draw the black ball even once?
In this thought experiment all the balls in the bin represent the landscape of all possible universes. The single black ball represents this exact universe. The white balls represent all other possible universes that are not this exact universe. The act of drawing a ball is the process by which the multi-verse takes a possible universe and makes it an actual universe.
Why is it that infinite possibilities require everything that can happen to happen an infinite number of times? Why can't certain configurations of matter occur just once?
@@demonbox7780 Perhaps, but as another science video I watched recently pointed out, belief in an infinite universe is not falsifiable, and thus is not scientific.
@@richmigala2539 Because give infinte chances (both spatially and temporally), and also that one black ball will be infinite, so you'll eventually end up draw it out an infinte amount of times.
I do not personally believe that's the "configuration" of the universe btw, just stated that from my very ingorant point of view is as likely, if not more likely than, life only happened and will only happen on Earth.
Using the ball analogy, at this very moment we are in a situation where, we blindly picked one ball out of a bin containing trillions of balls, we touched them so we know there are A LOT, just don't know how many and what they actually look like and contain.
That ball is the Solar system, we opened it and inside there are 9 smaller balls, our star and planets, out of these smaller balls we are pretty confident only 1 has at it's core the elements to create life, but we haven't had a chance to open the remining 7 balls so can't be 100% sure.
Now how can we confidently say that's the ONLY ball who could muster life in the whole bin?
I always get excited when a new Cool Worlds video drops.
So do I. Exciting, informative and fascinating, and very well presented.
Besides for what was mentioned in the video, there's another problem with using a 20x multiplicative factor of how likely it should be to find ourselves living around a red dwarf. So ok, on average red dwarf stars live 20x longer than sun-like stars. However the universe is extremely young, I believe it's not even 14 billion years old, i think it's like 13.7 billion years. From what I could find, a sun like star (specifically G2, which admittedly is more narrow than the range of "sun-like" stars used in the video, but that's the classification of the sun) will fuse hydrogen (be in the main sequence phase of life) for about 10 billion years. That is over 70% the age of the universe. There just hasn't been enough time for sun like stars to be born and die and go through multiple generations for the 20x longer lifespan of red dwarfs to contribute to the likelihood of finding us (or any civilization) living around them by anywhere close to 20x. Sure red dwarves may live 20x longer on average, but there hasn't even been enough time for 1.5 generations of sun like stars to be born and die, let alone 20 generations.
We need more scientific papers like the one discussed here. If someone can write about a statistical uncertainty and get published. Then so many more ideas can be brought to life with solid research that any journal browsing can supply information for. I like the guy before this video, but now I can enjoy it as well.
The more I watch, the more curious I become about the universe. I am a medical student who is deeply bonded into Astro and theoretical physics, love your work.
Stay away from abiogenesis and you'll be just fine. It's a dead field of study that has made zero progress in like 60 years, quite literally.
@@JustinOhio
But do ask if red-dwarf systems are unlikely to gestate life not only because of hostile stellar conditions , but because the Earth-like planets age and die .
Yoooo same here dude!! 😎👊
I would like to add a thought to solution III: The significance of the longevity of red dwarfs may depend on the point of time at which our galaxy and our neighborhood within that galaxy became friendly to complex life. If it was very active in the beginning - e.g. many supernovas, many quasar jets or other radiation events - evolution of complex life on early red dwarfs would be been difficult. And red dwarfs which were born before lots of the more heavy elements emerging from such supernovas arrived could miss some of ingredients fostering the evolution of complex life. So the early red dwarfs in general would not be good targets for the search for life. Maybe it is even only "our" generation of stars (meaning stars with roughly the same age as our sun) which we should target - and then it is only the quantity, not the longevity of red dwarfs in this generation we should incorporate in our calculations.
Were red dwarfs common in the early universe (12-13bill yrs ago) ? Or did they only become the most abundant type of star later in its evolution, say 5-10billion yrs ago? Curious to know, as it would have certain implications to the paradox as noted above... ie that red dwarfs born early in the universe's history would be poor candidates for finding life as they wouldn't have the necessary ingredients.
Wonder if there exists a population iii red dwarf somewhere out there?
thats a very good point
And then you can further reduce the quantity of red dwarfs as relevant because they suffer a lot more negatives for the evolution of complex (key word here) life. Tidal locking, solar flares, many factors that red dwarfs are more likely to experience than yellow stars because of the proximity of their Goldilocks zone. Could life still evolve in those conditions? Absolutely. But they’re very harsh to the evolution of _complex_ life. So the fact that we, complex life, find ourselves around a yellow star at a calm and safe distance rather than around a red dwarf as we get bombarded with solar winds and coronal ejections is not really a paradox anymore
My question is, are we asking the right questions?
"Where is everybody?" assumes life intelligent enough to generate techno-signatures. I can imagine, given enough time, life being everywhere that there is the energy and chemicals to support it. Maybe looking at types of stars and (our definition of) habitable zones is not going to solve anything. Perhaps life is everywhere, and the real question is what leads life to the intelligence necessary to generate those techno-signatures.
There was clearly some evolutionary pressure for our ancestors to develop the intelligence to understand counting numbers and being able to communicate that concept to others. Apex predators don't need to count, vegetarians with no predators don't need to count. Well, not beyond six or seven anyway. I've picked counting only as an example, I don't know what would have been important.
Maybe our specialness is not about our sun or our planet, but the very specific conditions that made it so intelligence would be a SIGNIFICANT evolutionary advantage. Without those conditions in our past we would be sitting in trees, perhaps even rulers over the carnivores of the Earth with sticks and stones.
But we're not throwing sticks and stones at lions and tigers, we're here at our computers thinking and communicating these very abstract thoughts. As far as I can find, we, collectively still don't really know how our ancestors made that leap. Julian Jaynes has some interesting ideas on what might have happened after that leap, but not what the evolutionary pressure was that took our brains up to that point.
Interesting there is speculation that a gamma ray burst causes the evolution of human. A cosmic event causes prolonged droughts in Africa forcing homonids to travel long distances too find food. This favors the smartest to survive because making the wrong decisions on where to go leads to starvation.
@@kazedcat I think the real answer is way more complex and involves the evolution of human conciousness. I do not believe that intelligence resulted soley from the need for survival. I believe true intelligence arose from the expansion of conciousness/self awareness. Self awareness is actually detrimental to instincts and survival and takes a back seat in a fight or flight situation. Conciousness and intelligence is something that arises after basic survival needs are taken care of. We could go one step further and consider that there are different forms of intelligence, being logical intelligence, and the other being emotional / creative intelligence. The right / left brain paradigm. One is derived from the need for practicality whilst the other is derived from introspection and self awareness. Intelligence that brings about any real advancement encompases both.
But the answer could also be a lot simpler; we do not yet know the length of time a civilisation will 'live', especially through its growing technological phase. Perhaps many civilisations have already existed on other planets and perished. Perhaps they did not escape their dying planets. Perhaps they wiped each other out before space travel, you get the idea.
The rate we are going we aren't far enough away from such a fate ourselves.
@@qwert_au Statistically improbable. Not only that, most arguments that touch on technology are tainted with bias and assumptions. Realistically our current level of advancement is extremely low to what it could be. Just another 1000 years of advancement there is an extreme probability that not only will we be colonising our solar system but also managing intersteller and intergalactic travel. It also hinges off the assumption that we will wipe ourselves out within the next 1000 years which is extremely pesimistic and partly a result of our inherent nature to catastrophise everything.
@@livinglight9915 i wonder if chemicals from mushrooms or even nutrient dense food had some case for our enlightenment…
How much would these odds be affected if you take into account multi-star systems, and if those systems are far less likely to be habitable?
First time watching your channel, just found it with this video. Great production here and fascinating subject matter. Definitely a well earned subscription!
What's the solar activity like on these M-dwarves? Could they sterilize themselves?
I believe they are prone to pretty nasty flaring when they are young. That could be really bad for planets in their habitual zone.
Fascinating...I'll give, in my opinion, the very best compliment I can. Your video's always make me think and give me a desire to go learn more, as much as I can on the subject. This video does that like almost all your videos do. Thx 4 the upload
"Red Sky" is not a paradox. Labeling it a paradox diminishes the significance of the word. It's kind of like saying "It's a paradox I was not born in Asia; there are far more people in that region, so how did I end up being born in North America?"
The people of Iceland are experiencing a terrible paradox!
Honestly your probability theory on intelligent life was accurate to my own theories. What counts as intelligent life is still debated on, but I still give life a high probability. When I found out about tons of life around volcanoes underwater, I grew a lot more curious about how life truly works.
I agree that there simply isn't enough information out there yet. Having said that, I'm truly excited to see what James Webb discovers. I feel like it's going to do a lot of interesting things to change our perception of the universe. I love Hubble, but I'm stoic for what James Webb will do. Also if/when Starship launches, it will be a lot easier getting even better satellites than even James Webb.
What is important though is James Webb. I've studied a lot about astrologists and reasonable theories and some felt off. I respect their work because it kept us thinking, but already JW has challenged them as well.
With complete regard to M stars having life, it's impossible to truly predict accurately. The best thing I can think of is looking for a specific one to try and study more thoroughly than Hubble. There is a lot of data in contradictory to what we're figuring out in months with the JW satellite.
I'm excited, even if it's bad news.
Thank you so much for your uploads. It's extremely refreshing to be given well thought-out facts that aren't accompanied with a presenter who also tries to be a comedian to retain my attention... My attention (and probably most people's who enjoy videos like this) is retained by your format.
Can the light spectrum emitted by M class dwarfs support photosynthesis?
M-dwarf spectra are similar to incandescent light bulbs. Plants can survive under that light, but not very well. There's just not enough blue for them to thrive. That said, plants on Earth are adapted to use white G-class daylight, not orange M-class daylight.
@@CubicApocalypse128 Thanks.
I very much so hope that the first life we do find is on a planet that we would never expect life to be on such as a gas planet just to prove to humanity that we are being too closed minded about how life can form.
I love this channel, it’s got the same kind of flair and standards as David Attenborough or even Brian cox, gives us so much info but leaves us questioning even more, coming away from this channel leaves you in awe of the universe a little more each time
It being a coincidence is plenty satisfying an explanation for me... the amount of coincidences and cosmic flukes that surround us at all times is astounding. As I see it, it isn't at all difficult to add one more to the list.
I have also seen studies suggesting that ultraviolet light is crucial in creating/evolving RNA like molecules. Red dwarfs just don't have as much ultraviolet light.
Thank you. This is what I was thinking also
Very interesting. I've never heard that and will have to look into it.
This could explaim the fermi paradox, as it would imply that live is rare because the majority of stars arent capable of developing life
This was also my immediate question about the likelihood of lifeforms not only being created in the first place, but having enough of the right amount and type of radiation to continue to evolve and ultimately survive across the number of generations it would take to become complex organisms. The initial creation of life could possibly happen all the time in these habitable worlds, but they simply don't survive long enough to become intelligent.
This paradox asks why we, as the infinitely complex organisms that the human species has become, did not emerge on a planet orbiting a red star. Well, we are only able to survive the amount of ultraviolet radiation that we receive from the sun because of the ozone layer of our atmosphere shielding us and bringing the amount of radiation down to a level that is tolerable for not only us, but that feeds the plantlife that sustains the animals we prey upon. However, this amount of radiation is also something of a 'goldilocks' attribute of our planet, because it also not too low. Too little radiation, and the plantlife would not be able to generate enough energy through photosynthesis. So ultimately, the problem of proper radiation exposure is one that occurs repeatedly along the temporal scale for the potential of producing intelligent life. All of the elements have to be just right, and that lessens the possibility of it occurring even more.
They haven't proved there is a paradox.
No magnetic shield, no intelligent life.
But, how how can they write papers proposing various solutions if there isn't a contrived "problem" to be solved?
This new video of yours is another great work of Science, Prof. Kipping...
Thank you!
Universe is still very young so the longevity part can be thrown out of the equation for now.
I believe that with our current knowledge it’s extremely egocentric to call our sun not being a red dwarf a paradox/logical contradiction.
Assuming that red dwarf systems are much more habitable then for all we know there might be a lot more, even hundred times more red dwarf star systems with life than there are yellow dwarf star systems with life. If the equations in this video are true then this would mean that ratio is as expected and we are just ones on the smaller side of that ratio.
So just because our earth is located in this particular star system type does not create a universe paradox, at least not as far as we know yet with our current tech.
Yes. I came here to say this same thing.
Additionally, our sun is a third generation star. First generation stars would have only had hydrogen to work with. Therefore no rocky planets could have existed (I think some helium and even lithium is speculated to have been generated during the big bang, but my point stands). This means that first generation red dwarves would have had no life just like first generation suns like ours. In fact I just found an article that says that the first generation of stars were probably all very large. The downside of this is that the stars probably burned out over the course of millions of years and therefore generation 2 would have been over 13 billion years ago already.
Second generation stars would have had more heavy elements. But is is possible here that the number of heavier elements would have been lower. This may have allowed life to form, but it is possible that advanced civilizations could not have come about. I'm just speculating a bit here because I haven't ever found a clear explanation of the generations of stars, even with the article I'm mentioning. The likelihood of red dwarves forming during this time period would have been higher, but we can likely ignore these stars. The article I was reading said that it is possible that "2nd generation stars" could still be forming today.
Third generation stars, like our sun, apparently come after these first two generations, but it sounds like, from the article, that they actually could be many generations later, we just can't really tell the difference once we get this far in. But if we assume that advanced civilization must come from third generation stars, then that limits the amount of time that the universe has been capable of generating suns that, in turn, have been capable of generation advanced civilizations.
Add to that the fact that it takes time for the suns to collect their elements which means there could be millions or even billions of years between the death of one generation of star till the next generation is capable of coming together. Then the fact that the planets take time to coalesce as well. It also sounds like, based upon other websites I found, that red dwarves take longer to become stable. In the end, the amount of time red dwarves have had to foster life that could evolve into intelligent species which could, in turn, harbor advanced civilizations might not be any longer than our sun has been around.
In other words, it is my opinion that the longevity of red dwarves actually works against them. There might be more, but the older they are the less likely they are of being capable of creating advanced civilizations. We could ask this question reasonably in 50 billion years, but at this time in the history of the universe, suns like ours might be the only places that advanced civilizations COULD form.
i absolutely love the idea that were just here by luck. makes me feel all the more thankful im alive
Great channel, pretty stoaked about finding them !
We're stoked you found us!
The intensity with which you work, evident from your published papers, is inspirational. I look up to you and your videos for that among other highly intriguing astrophysical material.
Everything i've researched on the subject seems to indicate that m class starts aren't particularly suitable for complex life, k class stars seems like a better option to focus on.
What about the paradox that only species who evolve around a sun-like star talk about this paradox.
But as the universe is only 13.8 billion years old, the longevity of red dwarfs won't come into calculation as we are making observation at the age of 13.8 B and not 100 T. So, the chance will be 1 to 5 and this explains coincidence. Please correct me if I am wrong.
Congrats on new paper! As always, wonderful questions and brilliant thoughts from CoolWorlds.
I just love this channel, 10 years ago there was no way we would have had information or videos like this readily available to us. Such a blessing.
It's true. We are getting smarter.
Physics is amazing for its beauty and universality of content, that's why physics is the king of all science and knowledge.
Well, I’d probably toss that honor to mathematics, from whose womb came physics and chemistry, high-achieving and well-behaved, respectively, and followed by engineering, off to war again, and of course, geology, with his head in the sand, and biology, evolution, anthropology and medicine perennially too young to worry about the future. But they’re all darlings, to a fault. (Not a bit like their father, thank god.)
What so many people don't seem to TRULY understand, is for us here on Earth, life and all that it is has little to do with the star other than that the sun is a handy source of energy - but not until life here learned how to utilize it. There is some ongoing cutting edge studies which is shining light on the growing, mounting probability that terrestrial life is FAR more deeply connected to THIS planet than we generally conceive. Which is to say that the physical syntax allowing us to be here is of a very different order than the thought, logic, and linguistic syntax we have been using to try and apprehend the circumstances of life here. Put overly simply, and from a different angle, and perspective, we don't live on a star. We live on a Planet which we are part of. This planet like ALL planets is involved in a very complex intercourse with many MANY factors, chemically, electromagnetically, quantum mechanically, just to name the tip of the iceberg - And like all planets and stars our situation is very unique, and one of a kind. I would stake anything on a wager that we will come to realize this the very hard way if at ALL.
So to me there is no paradox, and no surprise concerning our star. Microbes out number humans millions to one and they have and will for as long as life exists during which time human form has been only one fraction of an eyeblink compared to a full lifespan - why was I born as the human I am? Yet we must realize that We too have likely been around for millions perhaps billions of years in various forms as adaptation and evolution shaped and reshaped our form and species, until finally going for broke here we are at the brink of extinction and too stupid to accept our stupidity may very well prove far more formidable a foe than all other existential threats we know of combined and X 10.
I AM being optimistic and positive. Things are a lot worse these days than almost everyone may think. Unfortunately. If we live out our natural lifespans - those alive NOW - it will be a fucking miracle, and realistically about as much as we should expect in ANY event.
As a kid I remember "Pinocchio's paradox," which starts with Pinocchio saying, "my nose will grow now..."
If you're not familiar with it, let that statement sink in, and let the imagination run with it.❤😃
You help make Earth its own cool world! 😎
Did I hear a Sagan impersonation when u said "pale red dot"? Loved it!💙
We're looking at habitable zone and stable star, but we should be looking at shielding Jupiter and a stabilizing moon as well, if we ever think about finding complex lives in exoplanets.
Yeah, but these are just Earth based, human philosophies. I mean Jupiter may shield us from SOME things, but space is HUUUUGE. Global killing asteroids can come from SOOOO MANY angles in space, that even Jupiter can't block them all.
And having a stabilizing moon. Sure, but more Earth based assumptions. Human life may have done just fine even without the moon being apart of our system. There's just no way to prove tha the moon guarantees us any better successful survival and evolution than being without one.
Being in the sun's Goldilocks zone is 99% of the reason why Earth has life on it.
@@blackSUAAAVE i'd disagree with certain points. In my opinion when it comes to probability, proximity to projectiles increases the odds of it teaching us so most of near earth object usually originate from oort cloud or from asteroid belt rather than from outside solar system so i still feel Jupiter plays a major role in reducing mass extinction asteroid event though that's not fool proof, we've had many mass extinctions in past to explain that. I'll rephrase my thoughts about moon, a planet with a stable rotary axis is needed for complex lives to evolve, for us it's provided by moon, (for exoplanets it's very difficult to bet on its axis) constant shift of axis will destabilize life from evolving to complex forms.
@@MrDocAKS - Yeah, but we don't have examples of 'almost life...but they didn't have a moon' planetary systems out there. Sure, it a bunch of Earth like planets were out there, but were barren because they just couldn't quite get the same things we have here on Earth...YES. I would buy the idea that a moon is necessary for life as we know it.
If a planet sits in the Goldilocks zone of a stable star, and that planet has liquid water, a magnetic core, an atmosphere, has seasons, it's going to have some form of life on it.
Jupiter doesn't even cover 1% of the sky, so how can it be this guardian angel that's keeping Earth protected like a rugged bouncer at a night club?
I'm not saying space isn't violent and chaotic. It is, but that's early stages of solar system formation stuff. Once it reaches a point of measurable stabilization, i.e. 2-3 billion years or so into forming itself, all the planetary bombardment of celestial bodies really thin out. Orbits stabilize, the planets 'clean up' around themselves, i.e. pull in or eject smaller bodies around them. Once they clean up, they start to...improve, and evolve.
There is life out there in the universe. We humans are just not advanced enough to discover it yet. Some planets only have plant life on it. Some planets have plants and animals. Some have plants, animals, aquatic animals, and yes...sentient beings.
Whether or not all of these sentient planets have moons or not is immaterial. There's more than one way to have life on a planet. Having a moon is only one way for it to happen.
I guess I don't understand what the longevity of red dwarves has to do with the emergence of life at this point in our universe's existence. If we were somehow looking backward at the end of time, long after all the stars had burned out, and THEN we found that life only emerged on this one Yellow dwarf star that burnt out 1000x faster than it's red dwarf counterparts, then we could say in retrospect, perhaps longevity isn't a factor.
But right now, Universe = 13.5 y/o give or take, Sun/Earth = 4.5 billion y/o give or take, Bernard's star = 10 billion y/o give or take, Alpha Centauri 5 billion y/o give or take. 5 billion years is nothing to sneeze at, but in the grand scheme of things EVERY star that has ever existed, even those that have collapsed or exploded was/is a baby compared to how old these baby red dwarves will become. It's sort of like putting Mozart next to a million other 8 year olds and wonder why the only musical prodigy was born in Vienna.
There are far more bacteria than human, therefore I am more likely to be a bacteria than a human...
I wish I was a red wood just chilling in a national park
Another gem of a video. You really do 'hit the nail on the head' with these. Even the 'ads/sponsor thanks' are relevant. The comments below are thought provoking too. It is great the way you avoid lurid speculation/cheap sensationalism and present statistics and astronomy in a way that is far more fascinating than science fiction. Keep going!
Thank-you Ian!
Ok, we're Flukes. Nevertheless, I prefer to think of myself as a Flounder. P.S. Fascinating video, Sir. Well done!!
Wish I had teachers of your caliber in my youth, someone that is clearly passionate about sharing knowledge than getting an "easy" salary.
I think you overestimated the time advantage of M stars given that the current age of the universe is only 13.8 billion years old. When factoring that in, the time advantage of M stars only gives about 2x the advantage in frequency at the current time, but will grow through time. When factoring this in I think you're only talking about 90-10 advantage for life around M stars, which is significant, but not crazy odds.
Our sun is a third generation star if I remember correctly, which means we have all those heavier elements created in previous supernovas as building blocks from when earth formed.
Considering life here on earth is contingent upon having a big variety of chemical elements, perhaps life has a much harder time - or simply cannot - form around a “first generation” star, because there aren’t enough of those needed elemental building stones in the protoplanetary cloud?
If an m-dwarf star can live much longer, perhaps many of them are still these old “first generation” stars, whose planets are thus created from this first protoplanetary disk, before any supernova has occurred. This would mean that those planets don’t have enough of those metals and heavier matter that can only be created in supernovas.
If this is indeed the case, that “first generation” stars cannot have life, then perhaps the apparent abundance of red dwarves caused by their longevity is actually to the red dwarves’ _disadvantage_ when it comes to creating life.
I imagine this would mean that the amount of red dwarves that actually have suitable rocky planets aren’t as abundant as our initial sample size suggests, if many or all of the first-generation (and perhaps also second-generation) stars can be discounted.
Is this a reasonable conclusion, professor David, or is there something fundamental that I’m missing? 😅
Im so intrigued by astronomy and alike. Your videos are awesome i love it. Its literally like crack. Keep up the videos man ive gotten through so many rough times with these astrological videos its unreal. Thank you
I have been evangelizing your videos to all my friends and forcing them on my boyfriend.
I love exploring concepts related to the universe, it's what got me into physics and engineering. The Cool Worlds channel is the single best science channel out there.
P.S. can you put out the background music for purchase or on something like Spotify? I'd love to listen to it at work while coding/problem solving.
Thanks professor Kipling! Keep up the awesome work.
😆Sounds like you'd make a great Jehovah's witness
I am a simple man. I see a Cool Worlds video, I click.
Don't underestimate yourself. If you watch this....you are.....at least.....curious. That's an admirable quality. Professor Kipping is the best!
There's one aspect that is rarely discussed and seems to me like a major factor but it may as well be that I just don't understand the problem behind Fermi's paradox.
So, why do you expect to see any alien life right now in the first place? We barely can pick up shadows of a small fraction of planets orbiting other stars. Or is it that people's expectations of alien life got skewed by SciFi so much that they get cranky for not seeing death stars zooming around, chasing Enterprise type vessels. I guess we (humans) are so damn important, we're waiting for that official invitation to the galactic federation.
All that while we still fail to apply realisting expectations to the current state of knowledge according to which interstellar travel is nearly impossible (for humans at least). Currently the best and fastest known way of information propagation is with c and if you travelled out 100 lyrs out with the best realistically sized antenna would you be able to receive, recognize and understand early human radio signals?
I think there's the step 1 of answering the question and only when we actually gain data coverage we can consider paradoxes within.
Isn't the biggest problem the fact that most planets in red dwarf systems in there habitable zone are tidally locked to their star? As stars get bigger, the habitable zone grows so less of a chance for tidal locking. Tidal locking doesn't preclude the development of life, but it does make it harder for complex life to develop. When we say "life" don't we really mean life with advanced civilizations capable of space travel? It's not that scientists wouldn't love to study a planet with green goo life on it, but that's not what we are really wanting to find.
If it hadn't been for a timely asteroid impact, earth would still be a dinosaur planet. Our large moon gave us seasons. That may or may not be a big reason for the development of advanced civilizations. Even if intelligent life develops, how often does it get stuck at some low technological level? If it does develop advanced technology, how often does it destroy itself due to war or accident? Also, how often do cosmic events and asteroid impacts require life to start over? Finally, we may just be the first ones. In order for our complex biology to happen star had to live and die many times to produce all the elements we take for granted. As this video explains, it may just be too soon for life to develop around most smaller stars.
The Goldilock region for a red dwarf star is too close to the star. The bad temper of the red dwarfs would scorch the nearby planets to be lifeless.
over the billions red dwarfs calm down in emissions
David breaks everything down into common sense and awareness, he has really opened my mind to all possibilities. Thank you Cool Worlds Lab for all you do!!!!!
Truly openminded? Take a look at plasma cosmology.😉
This channel is just wonderful. After 2-3 years out of university i am reading a scientific paper again (at 11pm on a thursday). Even thou i studied social science, the cosmos and astronomy is still my favorit subject since my childhood. Thank you CoolLabs and Prof. Kipping! It is truly a joy to watch your videos
The Fermi Paradox is so dumb. It's so narrow-minded and can't fathom how insignificant life actually is.
First of all, love your channel! Thanks for the great content; it's super accessible and digestible!
I'm a bit confused on an aspect of the red sky paradox and was wondering if you could help clarify my thinking.
Since the universe is roughly 14 billion years old, I'm inclined to think the difference in lifespan between Sun-like stars and M-dwarfs has no effect on the probability of finding life around either of these two types of stars at this point in time in the universe (since the time advantage of M-dwarfs hasn't kicked in yet). This leads me to the following questions:
1. For any life that happens to exist in this period, would the chances of existing around a Sun-like start fall back to 1 in 5?
2. Would this viewpoint then reframe the paradox to more of "why do we exist this early in the universe?" rather than "why do we live around a Sun-like star"?
Thanks for watching. The current age of the universe is only relevant if you assume that civilizations can only emerge in times ranging from the Big Bang until now, if they can emerge whenever in cosmic history then this dissolves. Great question though!
@@CoolWorldsLab Thanks, that helped provoke some thoughts that let to me figuring out where my confusion lies (although it's taken me quite a while to actually figure it out, and please correct me if I'm wrong at all). So most of the video is spent drawing conclusions about the topic of civilizations emerging at any time in the Universe. The end of the video uses the conclusions to help decide where future life-hunting telescopes should be pointed. However, if we are searching for life, we can only look at the present and past, which should then mean the age of the universe is relevant, and the civilizations we are looking for are equally likely on Sun-like stars and M-dwarfs.
I think you are correct that it would revert to 1 in 5 If it is taken as a given that the universe is 14 billion years old. This, however is not the assumption, as when we find ourselves in the universe, one looks at the universe's entire history as the substrate for the relative probability of our existence. Mind bending and counterintuitive to be sure.
@@CoolWorldsLab Assuming that civilizations can only emerge in a small window of time is correct. We exist now, not in the future. What counts is the conditions now. (And not too far in the past either, time was needed to build enough heavy elements).
Imagine you are an early human, 200,000 years ago, living in Ethiopia. You wonder why you are living in Ethiopia, given that the vast majority of people who will ever live, will live somewhere other than Ethiopia. It's because, at the time, everyone lived in Ethiopia.
You might be able to wonder why you are living at the *time* you are living, but the question of the *place* you are living is already answered.
And wondering why you are living *when* you are living is just the ancient question of "why am I me, rather than somebody else." This is not really answerable, and certainly isn't scientific.
I cannot believe the quality of the content that David uploads. And not only is the quality beyond amazing, the channel is also consistent with its uploads. And people wonder why less and less of us watch tv. There's no tv station that offers content this incredible.
Completely agree. Why would I bother watching most of TV when I can spend my time and brain cells on intellectually expansive content.
I watch your videos a couple of times each, to learn and be amazed and fall asleep. Your and antons channel are blessings! 🙏🙌🌻
You failed to mention that red dwarfs planents in their habitable zones have orbits that result in planents being tidally locked. This, along with the heavy radiation flares and coronal mass ejections (CMEs) associated with red dwarfs are serious factors in regards to intelligent life arising around this star class. The tidal locking means no protective magnetophere from any cosmic radiation, including the additional radiation exposure from cosmic rays.
Potential resolution:
The fermi paradox and red sky paradox both account for the statistical probability of life by examining planets conisdered within a habitable zone. It would seem they do not account for the likelihood that human level inteligence would form. Could it be possible that the earth exists within a zone where life is possible but also that life is exposed to such high levels of mutagenic radiation that evolution and mutation becomes accelerated. A potential solution to the fermi and red sky paradox is that human level intelligence is very uncommon due to a very strict celestial circumstance that allows intelligence to form within a fast enough time scale.
Its not unlikely for intelligent life to develop around m dwarfs, we were just early to the party.
You guys are really smart. In a funny way. You are creative, and funny enough this lets you make a new step in physics. Discovering statistical possibilities of living planets in a galaxy. Exciting!!
:)
You are an incredible clear and gripping communicator, thank you for all your fascinating insights, love from Scotland
I never really understood the argument of "how can we be here if it's so unlikely". Let me demonstrate that with lottery: the chances of winning a lottery are 1 in... a lot. Several millions? Let's say a million. This means that no one has a real chance of winning... yet someone always wins. We won the "yellow star lottery", unlikely as it may be.
If we are to apply Fermi paradox to ourselves. Wouldn't it make more sense why our star is a yellow star? As in we beat the odds in comparison to "possible" intelligent life forms emerging. I feel like sometimes simple answers to intuitive questions fairs best.
This doesn't factor into the Red Sky Paradox, but I have also been fascniated by the sheer luck that we live at the perfect time on Earth that the moon and sun are the same apparent size in our sky, despite the sun being millions of times larger than our moon. And because of that we can witness a total solar eclipse, on our own planet.
Why don't i live in India? It's the most populated country. I call this the red dot (bindi) paradox.