Q&A 31: Is Contacting Aliens Our Worst Mistake? And More
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- Опубликовано: 5 сен 2017
- In this week’s question show, Fraser wonders if science is the best tool we’ve got, if communicating with aliens is a wise idea, and how he feels about people falling asleep to his videos.
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Team: Fraser Cain - @fcain / frasercain@gmail.com
Karla Thompson - @karlaii / ruclips.net/channel/UCEIt...
Chad Weber - weber.chad@gmail.com
Chloe Cain - Instagram: @chloegwen2001 
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Your wife laughing at the 'bald' question was just the best. (from a fellow baldie)
She couldn't believe I threw that in there.
Great vids, Fraser. I just discovered them a couple of weeks ago and been binge watching them ever since. But I recognized you because someone subscribed me to your old, plain text emails you used to send out like 20 years ago! Back then I used to print them out to prove to my friends how nerdy I was because I thought the info was so interesting. It's great to see UT has come so far. Keep doing what you love, man.
Yup, I started those text emails almost 20 years ago. It's nice when you've found your life's work. :-)
I think it's great that we are probing the universe for aliens.
Personally, I'm tired of aliens doing all the probing.
Yeah, let's see how they like it.
Yeah! Go Voyagers! Bend over Aliens! (We're gonna probe them with something else soon, right? cuz it's been a while)
If we built really big probes, would the aliens get an inferiority complex ?
James: maybe that spacex-guy saw your comment... en.wikipedia.org/wiki/BFR_(rocket)
He's definitely a DOOM fan. But he is putting his money where his mouth is and he's gone a long way in a very short time. Not so sure why anyone would want to go to Mars though, there's nothing much there and it's a bugger to land on. More money in asteroid mining surely, especially in Jupiter's trojans where the rocks are more closely packed together. Lots of precious metals and useful stuff like iron and titanium to build things with.
I often fall asleep to interesting shows. I can't sleep at all when crap is on! ;)
I remember Hyakutake really, really well. Amazing sight!
If that makes you happy ;)
Another particularly good Q&A segment, Fraser. Thanks so much for sharing.
Steve
Thanks! I'm glad you enjoyed it.
Thank you so much for answering. The sheer fact that you did on top of that exciting info had me giddy.
Again, thank you. 😊
Thanks for asking. :-)
Good choice with the head shave. Looks so much better than a comb over!
Glad you were able to see it. Glad the clouds didn't obstruct your view.
Love your vids Fraser.
Keep up the wonderful work that inspires us and keeps us all thinking!
Your Question Shows have just made me realise something - I have learned so much from this Channel and from Astronomy Cast with Dr Pamela Gay that to me at this point giving answers is easier than asking questions - the questions I have now cannot be answered because the actual hardware and research has problems keeping up with you :)
And that's why we need bigger and better telescopes, to answer current round of questions and allow us to ask new ones.
Love your videos thanks so much for the opportunity to watch the videos you make ,
I am learning so much keep it up.I am hoping that some day in the near future i will be in a better position to become patron!!!
Thanks again
Thanks for watching, I'm glad you're enjoying them.
Hi Fraser. I'd love to hear you speak about the properties of the vacuum of space (i.e. how many atoms are in a cubic meter in galactic space as opposed to intergalactic space). The idea that the vacuum of space isn't truly empty fascinates me. Great channel!
...your absolutely wright Fraser ...I was watching the sky 20+ years ago and I remember the comet was almost covering the whole ,,ceiling" ...from horizon...to the other horizon....that was a fantastic ,,picture"....I wish in my lifetime see again something similar to that......magic
I've fallen asleep to Pamela's gorgeous, soothing, voice SO many times. And yeah, yours is ok too. I guess ;)
I always listen again when I'm conscious though, promise :D
As I said, even if you don't, helping people sleep is important work.
Can't wait for astronomy cast start new season! I've been falling asleep to issac arthur's video this summer.
New episode starts tomorrow.
Hey Fraser, thanks for answering my quastion!
Thanks for asking it.
A fantastic show. Very interesting. Thanks.
Hi Frasier, I'm new to your channel and I've enjoyed watching your videos. So far, I like your Jean-Luc Picard answer the best, it was awesome.
Thanks for watching, I'm glad you're enjoying them. :-)
Holy cow. I am my friends started out with the plan of going to Carbondale.
We looked at the weather that morning, and decided our best bet was to go into Kentucky.
We ended up in the little town of Marion, Kentucky.
This proved to be a great bet.
We had a beautiful clear skies.
Our plans for 2024 are already beginning.
Good call. You've got to be ready to travel on the day of the eclipse.
Truly amazing the power of a telescope/sensor that can analyze the light reflected off an exomoon and determine the distribution of seas and continents of the world it orbits.
Yup, once the next group of telescopes go up, especially with coronograph starshades, the exoplanet research will really take off.
Wish I could hit a like button, when I learn something off each these different answers. Lovin the shows..
Only do it in odd numbers. Even numbers cancel out to zero. :-)
Love your show great job keep it up 😃
Thanks a lot!
I always thought it was a bad idea to advertise out into the universe that we exist and where we are, because you just don't know what other intelligent advanced beings are out there, some could look at us like how a lot of us look at animals, and farm us and keep us as livestock for food, others might want to torture us for fun, experiment on us for the greater good, whatever, who knows what mindsets other beings could have. But you make a great point that surely if they're intelligent and advanced enough to be able to decipher the plaque, gold record, and make their way over to us, then they would be intelligent and advanced enough to already know we exist and where we are without finding Voyager.
Let's just hope they think we make great pets.
You suggested Astronomy cast to me not long ago and i found it very hypnotizing. Great content, especially reviews on all the sci-fi books you guys read. But yes, I fell asleep. WARNING: dont fall asleep on your computer chair!
Great video! Keep it up!
Thanks, I'm glad you enjoyed it.
I favorited this video due to your first answer, the one about math!
Thanks! I hope the other answers were favorite-worthy too.
Aw man, that's a shame about the cloud cover : (
That was my biggest fear after driving 800 miles to see it. It was partly cloudy all day and i was watching the sky like a hawk, thinking "we go that way if we need to!". All of the sudden, 10 minutes before totality, the entire sky cleared around the sun in every direction. It was incredible, man.
So lucky. That's what we had right after totality. Within 10 minutes, not a cloud in the sky.
Good luck in 2024.
I know I'll be there.
The thing I would like to see in my lifetime is a supernova, naked eye. I hear Betelgeus is ready to pop.
Yup, it'll go off any day now, or within the next 100,000 years.
1:39 Them birds just want to be in your video..
That was the universe mocking him! :-)
They always do. We've had to shut a shoot down for 30 minutes waiting for a bunch of ravens to stop yelling at us.
The ravens were like: _Where is your science now Fraser CaaCaawwwwwwwwww!_ **poop** X'D
Fraser Cain never liked ravens not the animal or the football team ;)
CGI birds can be angsty sometimes
Terrific video. Regarding aliens knowing we are here, and attacking us, I would doubt that we have anything to worry about. My guess is that if a civilization has the capability to transverse the stars, they have already passed through one or more “great filters”, including the violent, aggressive filter we are (and have been) in. In other words, I would bet that an advanced civilization would have evolved out of their aggressive phase.
If the aliens can actually get here, there's not much we could do about them. :-)
Great video!!! Waiting for Astronomy Cast!!!
+Renan C Brazil next episode starts tomorrow
we went to Tennessee to see the eclipse, west of Nashville. We lucked out and the clouds went away in time for totality. We drove over 10 hours.
If the aliens are hostile it is too late. Actually that raises the question, why not sterilize every planet in the galaxy instead of waiting for competitors to develop radio, probably a century or two before we get interstellar spaceships?
That's the concept of Berserkers. We talked about this here: ruclips.net/video/vHMIv_zAbrM/видео.html
An interesting question. One possible answer is that if a civilization was advanced enough to get here, they would have evolved out of their violent, aggressive stage.
hahahaha falling asleep same here!! :D
It's okay, I understand. :-)
Was there in Carbondale also. Was an interesting event. Just like how you described, one small spot of the stadium, going up in cheers as one ray of light comes and swept across them moments before C2. It was infectious, getting the whole crowd going and just a peek to totality and the corona. The last moments of totality I could see prominences on the solar limb. What a moving experience. I'm disappointed that the weather wasn't perfect for it, but I saw enough to enjoy it, and that environment was very interesting also. Here's to 2024.
Yup, 2024 can't come soon enough. :-)
Fraser Cain Or 2019? Chile? I'm up for a trip...
It's possible that Paul Matt Sutter and I are planning such a trip. :-)
Thanks for the great show, could've mentioned that reaction wheels can saturate on use in addition to breaking. Also the different versions of evolution is a bit peculiar way of saying convergent evolution. It's not different kind of evolution, it's the same laws creating similar solutions without being genetically related. Since evolution tends to go similar routes without apparent family ties, it's fair to assume that planet with similar characteristics to earth would also have very similar flora and fauna.
Yeah, that was the word I was looking for, I just couldn't remember the term.
13:21 well, that was a *bold* question!
I like to throw those in too. :-)
That makes the channel even better! :)
Fraser,
I'm new to your channel, and have a quick question: you and Isaac Arthur talk a lot about the Fermi paradox, but what about a reverse Fermi? As in, if another civilization is out there, what are the conditions required to actually detect it, given our current technology and understanding of physics? How do these detection methods change based on the development and distance of that civilization? Am I correct in believing that, unless we were close enough to pick up our own radio signals, we wouldn't be able to detect ourselves?
Sorry if you've already covered this; I'm still digging through your library. But it's something that causes a lot of confusion when it comes to Fermi discussions. I also don't understand the incentive to become a K2 civ, especially since population growth tends to level off as technology and standards of living improve, and don't understand why the Kardaschev scale is so often taken as a given. I'm missing a core element of the philosophy.
Thank you for your fantastic content.
Thanks a lot for watching. As long as the aliens send a targeted radio transmission right at Earth, we should be able to detect it. Regarding the drive to K2, we don't necessarily know what will happen to our population, it'll probably peak in a few decades and start to decline. But we can see our overall need for energy just keeps going up.
Fraser Cain Oh, that makes a lot more sense. So basically, unless we happen to be in the direct path of a powerful radio transmission, we won't be able to pick it up? That means that either aliens would have to have good enough tech to spot us first and intentionally shoot a beam our way, or we'd have to have incredibly good luck, right?
I guess the Fermi paradox would still apply here, because our atmosphere had telltale signs of life over a billion years ago, which is plenty of time for somebody to pick up Earth's spectrum and set up a beacon in hopes of intelligent life eventually hearing it.
I wonder if humanity's energy needs will continue to go up, though. For example, if we could make our own fusion engines out of seawater, would we really bother building kilometer-wide solar panels? Besides, we could technically put the majority of our population into space and begin extrasolar exploration before even hitting K1, so maybe Dyson objects are just not worth the investment. Like yeah, they're possible and fascinating, but I'm wondering if they're the Philosopher's Stones of futurism. Then again, only one civilization has to be nutty enough to do it for Ol' Fermi could come into play again.
Again, thank you so much for your content, and I really appreciate your reply, too! Please don't feel pressured to keep the conversation going, as you've got a lot of fans (and I'm mostly just thinking out loud).
I always wondered if you could reasonably detect the polarization of light reflected off surface water of exoplanets.
I'm sure that'll be one technique they'll try.
Hi Fraser,Could there be another solar system closer that alpha Centauri?I mean have they looked in every single direction 4 light years.
Question: UY Scuti has the largest radius of any known star but is only 11 solar masses. What decides the density of a star, besides their stage in life? Why is there no larger red supergiant with say 20 solar masses?
I think a great way to look at the evolution on a different planet say compared to earth would be using Australia as an example...sure its on the same planet but Australia separated from Gondwana about 180 million years ago. Marsupials which are believed to have evolved during the Cretaceous solve a lot of the same evolutionary challenges with end results that look VERY much like their mammal equivalents. A great example of this is the Tasmanian Tiger (Thylacine) that went extinct in the 1930s. It was an apex predator like the mammalian wolves/tigers etc and looked similar but had a lot of unique characteristics.
I think it would be like that on other planets given variables close to earth. The closer the more earthlike the results etc. If you take a look at the skeleton of one of these compared to a timber wolf its scary how similar they are but thats due to evolution due to similar challenges/pressures.
Right, and that's the idea of convergent evolution, life finds the same result through different paths.
Yep, so my guess would be the closer a planet is to earthlike conditions the closer life will approximate what we see here evolution wise.
It really depends on the original DNA/RNA and the chemistry that life is based on tho. If it's even necessary to have DNA for life to form. It could be something entirely different. Imagine a life form that could feed directly from the Sun like plants here do but be animal like. There wouldn't be a need for predators then. Competition, if necessary would take a whole different route.
There was a niche in that ecosystem for a large carnivore, and no Mammals to fill it. So the role was taken over by a Marsupial.
Yep, look at ichthyosaurs, dolphins and sharks, one's a reptile, one's a mammal and one's a fish, yet, as they all live/lived in a similar environment and all eat/ate fish, they've all got a similar body plan.
Fraser Cain, the best way to describe the universe is interpretive dance! :-)
That's Paul Matt Sutter's approach - www.pmsutter.com/shows/songofthestars/
Wow! I had absolutely no idea that this was an actual thing! LOL! Thanks for the link. :-)
Question: Regarding binary/pinwheel WR-104 do we know yet if the GRB jets will be pointed at us? I haven't seen news of it for a while, but IIRC it could blast our southern hemisphere.. whenever soon by star standards. Keep your sunblock handy!
Can you please do a video with Isaac about Kepler, its catalogue, and a special focus on TESS, and its upcoming catalogue, and the potential implications?
Keppler proved to us that there is a great population of planets in our galaxy, but imagine how amazing it will be to truly take measure of their number? That's why TESS is my #1 favorite future space mission!
That's pretty specific. :-) I'll definitely do a video on TESS in the future, though.
Fraser Cain the "potential implications thereof" was why I brought in Isaac, and I'm not your boss! Hahahahaha. Looking forward to whatever you produce, however you produce it!
Hey Fraser, when does the Weekly Space Hangout return? You've probably said it but I missed it. Thanks
On the 13th at 5pm PDT. I'll make an announcement shortly.
I was in Carbondale (nearby Pomona actually) at a friend's house. We saw the entire eclipse from beginning to end. I tweeted Pamela to see if there was anything public going on. In 2024, you and Pamela are invited to join us at the same location.
Great videos buddy. Very interesting
Thanks for watching!
Fraser Cain Have u done any videos on the van allen belts I didn't see any? I watch alot of videos and read alot about them but I don't know what to believe. Some say we can pass through it and some say we can't. What are your thoughts on it?
Like, 5 episodes ago: ruclips.net/video/1tZs02kxTdg/видео.html
:-)
Fraser Cain Thanks didn't see it.
Your are right, Frasier. They have known life is here for millions of years. Now - we are just being observed...
I'm sure the reality show they're watching gets really bad ratings.
Reaction wheels seem like they would be incredibly simple pieces of equipment consisting of a weight (which can’t really fail) and an electric motor (which are very reliable on earth). What causes them to fail in space?
Also, on the question of what life would look like on other planets, in addition to chance, it would totally depend on the physical conditions on that planet (atmospheric pressure and content or strength of gravity, for example). If gravity were fairly low, there could be giant animals. If the oxygen content were really high, you could see giant insect-like creatures (as we did on earth when oxygen content was really high).
It's the motor part that can break down, especially if they're running often to re-orient the spacecraft. And nobody seems to listen to me when I say they should take more spares. :-)
Regarding life on other planets, we don't really know what it would look like, but convergent evolution shows us here on Earth that similar organs arise to perform the same function, like flight or vision. So they'd look alien, but I think we'd understand the gist of what they were doing.
I'm going to assume a Hubble constant of 71 km/sec/Mpc because you get the accepted value for the age of the universe from its reciprocal, which is 4.346e+17 sec, or 13.77 billion years.
Let's say that you observe something at the edge of the observable universe. You know that it was 13.77 billion light years distant 13.77 billion years ago. When you correct its position for the expansion of space, how far away is it now?
This is an integral problem, since the expansion of space itself increases with increasing distance, and the recession speed that the expansion of space causes is not limited to the speed of light.
We will walk the distant object forward in time by a (relatively) small increment, e.g., 100 years, and assume that the recession speed was constant over that little bit of time. We find out where it was a hundred years after we saw it. We compute a new recession speed based on the Hubble constant: 71 km/sec/Mpc. We compute a new distance, when the object was two hundred years after we saw it, based on that recession speed. Rinse and repeat, until the accumulated amount of time reaches 13.77 billion years.
With a 100 year time increment, the final (corrected) distance is 37.426062 billion years, and the final (corrected) recession speed is 2.7176023 c.
With a 1000 year time increment, the final (corrected) distance is 37.426061 billion years, and the final (corrected) recession speed is 2.7176022 c.
You can see that the integration almost converges when the time step is a thousand years, so there isn't any reason for me to belabor my computer with finding solutions with time-steps smaller than a century.
An even more interesting question is: How far away would a galaxy have to be observed by us today in order to have a corrected distance of 13.77 billion years, and therefore be on our cosmological horizon right now? I did the math.
It turns out that a galaxy that we observe as being 7.8105394 billion light years from Earth, and having an observed recession speed of 0.56714329 c, has a corrected distance of 13.771721 billion years and a corrected recession speed of 1.0000000 c.
It would serve no purpose for us to send any intergalactic spaceships to chase after galaxies farther away than 7.81 billion light years because they'd never catch up with the galaxies they were chasing. Not even if they could accelerate to within a cat's whisker of the speed of light. We can observe a very large number of galaxies that are, already, over the cosmological horizon and lost to us.
Here's the Python code. When copying the code, if you do, replace any underscores with spaces.
import math
pi= 3.141592653589793238462643
# conversion: seconds per year
k1= 3.15576e+7
# conversion: meters per light year
k2= 9.4607304725808e+15
# speed of light in m sec⁻¹
c = 299792458.0
# Hubble constant in sec⁻¹ = 71 km/sec/Mpc
H = 2.3009532955054991665e-18
# Observed distance (where it was), LY
y = 7.810539401e9
# Observed distance (where it was), meters
d = y*k2
# time step in years
dt= 100.0
# time counter, years
t = 0
# initial recession speed, m sec⁻¹
v = d*H
# output initial state
print(d/k2,v/c)
# integration loop
while t
I read once years ago in community college that the 4 forces were once one force near the beginning of the universe and seperated when the universe cooled, could you shed some light on this please? Love your videos btw
I think you've pretty much got the gist. Moments after the Big Bang, each one of the forces separated out as the Universe cooled. We talked about it a bit in this episode: ruclips.net/video/icdeQ7HLc7A/видео.html
Is a swing by therotical possible at a black hole and how much speed could it add if so?
That's a good question. You'd have to avoid spaghettification, and would also need to work out after time dilation whether you actually save or lose time doing it.
Yes, you could do a slingshot past a black hole, and theoretically, you could gain enough speed to go relativistic speeds. Of course, then you'd get torn apart by the forces.
Any thoughts on The Three Body Problem by Liu Ci Cin?
I finished it! I liked it a lot, especially the last 50 pages or so. I've gotten my hands on the second and third books now, so I'll pick them up shortly.
Hi Fraser, I have a question - sort of a rehash of a question already asked. It's about time dilation and gravity wells. You answered this recently but .... sorry ..... not really to my satisfaction bro :) We know that the deeper one gets inside any sort of gravity well the more slowly time passes, right? GPS satellites correct their clocks daily to compensate for the difference in time out there, right? Well, when the other user asked you about inter-galactic space and how time 'flows' out there away from any large gravitational source I got the feeling they were curious about the 'natural' flow of time.
Our units for measuring time are quite arbitrary, mostly based upon the rotation and orbit of Earth but ok, let's just take a second at sea level as the standard unit of time - a tick or a tock. What I'd like to know is ...... what would be the length of a 'second' out there in inter-galactic space compared to our standard unit? 0.75 of our second? 0.8? There's has to be a natural time unit, right? I mean, we can't really say that the rate at which time passes is 'universal', can we? Because it depends on whether or not you're inside a gravity well and how far inside it you happen to be. However ... there ought to be places in the universe where gravity has such little effect that the passage of time is .... natural, unaffected by gravity. places where the flow of time would be constant and somewhat universal.
This is quite different from relativistic time dilation too, isn't it? Time dilation as we usually know it is due to velocity and not gravity so I guess the ultimate question here then is .... how does time flow when you're not moving at all and there's nothing near you to create gravity? Cheers!
edit: by the way, _if_ governments really did have alien tech why would they keep it in some desert facility here on Earth? I mean it stands to reason that the one thing they'd want more than anything, if alien contact had been made, would be their means of propulsion and once you had that you've no longer any need to remain here on Earth. Once you've got the propulsion you can go wherever you like, cart around as much building material as you like, plug up a large asteroid maybe and stick your space program in that. It would be a lot easier to keep a secret space program secret if it were off-planet, wouldn't it? If the people involved in it aren't here on Earth then they can't betray the secret, can they? Just some food for thought there bro :D
Time is completely relative depending on your speed compared to someone else. When you're walking around, you're experiencing time differently to people who are sitting down. We did a video that talks about this here: ruclips.net/video/JWncwRTMKkI/видео.html
Thanks - I hadn't seen that video. Time flow is a doozy - hard to wrap the head around. I was inspired by that previous guys question to wonder .... is there a natural 'rhythm' to the universe. Like the nature of a wave, everything ebbs and flows, it's all ups and down, ins and outs .... a dynamic universe that see-saws from positive to negative and back again. Even though the passage of time is relative from our _perspective_ .... if it's the length of that second that's variable, might there not be a sort of 'universal second' that _everything_ else is relative to? You don't have to answer - I'm just wondering out loud here. Cheers :)
Fraser, you mentioned we will have telescopes which will be able to peer through to the edge of the observable universe, can you speculate what we might be able to see, and would there be images or just data? Thank you
In theory we should be able to see the first galaxies forming, just a few hundred million years after the Big Bang.
I have heard a lot about missing anti-matter in proportion to matter. Would anti-matter have an opposite lightcone from matter if observed from the big bang?
I'm not sure why it would. Antimatter is the same as regular matter, it just has an opposite charge.
If humanity becomes a primarily space faring species, do you think we will still use seconds as our unit of time considering it is completely related to the time on earth. And how would days/months work for an interplanetary species?
You are showing your youth, I saw comet hyakutake in New York City, Yes it was fully viewable in Queens. It was great I could only imagine seeing it in a dark location. As for 2024 we live in Buffalo now, come visit great location, rain shadow from Lake Erie.
You should get a nice view to the 2024 eclipse, I think I'll try to see it in Texas.
I've got a question: why it is believed that water is necessary for ANY (i.e. alien) life to evolve?
Solar eclipse was great to see, but it was also very disappointing. I went to an area with 95-95% totality and it just looked like a cloudy day with a strange grey haze for less than two minutes.
95% is totally different than 100%. I've heard it described as the difference between seeing a lightning bug and seeing lightning.
Mr. Cain will it be possible to determine if an exoplanet has a magnetosphere?
Yes, check this out: phys.org/news/2014-11-magnetic-field-exoplanet.html
Well I for once avoid your videos before sleep. Sometimes it's 3 am on a workday and I'm rewatching old episodes.
So they keep you awake? You need to find those sleepy videos, try listening to Astronomy Cast. :-)
Glad you enjoyed the eclipse.
1:45 "Anything better than math ... to understand the universe" Well, physics, and science more generally. But I suspect that's not in keeping with what your questioner meant and won't satisfy him.
My answer would be to explain what math is, from which it follows that there are no sensible substitutes for it. Math is just the study of absolute truths, truths that we can know without using physical experiments or observations. If you had some other real way of studying absolute truths, well, it would *be* math. For instance, when Kurt Goedel broke new ground with his undecidability proof, or when Georg Cantor did the same for infinities, those new methods were immediately recognized to be mathematical, though they had never been seen before.
You could make a similar argument for the uniqueness of science - if something else made reliable predictions about the world as a consequence of repeatable experiments and observations, that thing would be science.
And at the end of the day, it works.
Can telescopes detect objects in space obscured by other, closer objects in their line of sight/signal and, if so, how?
Not really, in some cases you can get gravitational lenses, where the foreground object acts like a lens for a something behind it: ruclips.net/video/H1bZcdE9zP0/видео.html
Hi Fraser! Can you explain if the Neutrino is smaller then the Electron? Also, Is there a place in the universe that's at Absolute Zero Kelvin (-273.15 Celsius) or below. If not, what's the coldest we've measured?
Neutrinos are the smallest particles ever measured. No, it's impossible to ever get to Absolute Zero: ruclips.net/video/wl66BIgfHGk/видео.html
Could you please explain how CERN is funded?
In case of quasars, what would happen if regular matter was replaced with dark matter only? Would our equipment be able to detect the effects, if so, would we be able to tell the difference? Thanks, love the show!
7:59 MORE TORQUE!!!
Hi Fraser, my question is it possible that dark matter has gotten trapped down in Earths gravity well and takes up a probably very very small amount of Earths mass?, if so how small or large is it? Or will we never know.
Another question is could pockets of dark matter mess up a trajectory of a spacecraft during a interstellar journey?, is their anyway of detecting these if their are any?
If stars in a region of the Milky Way were dimmer on average compared to the surrounding region, how much dimming would be noticeable? Also, how big would this region need to be for the effect to be noticeable - 8 degrees across? 16 degrees? 90 degrees?
I'm not sure the exact size, but that sounds like the kind of thing you could discover using the Sloan Digital Sky Survey, for example. Gaia would find that kind of thing too.
Another question about the ''star shot''. These probes will be travelling at say 10 to 20 % of the speed of light so will there be a kind of ''red shift'' in the radio waves that will be transmitted from the space craft? Will this ''red shift'' be enough to make communication difficult?
Not really. You can still hear an ambulance clearly, when it's driving away from you.
There will be a little bit of red shift, but it won't be that bad.
Starshot initiative will pass across oort cloud. There are serious chances of It coliding against any object there? And why sending the ''starship'' across the cloud? Wouldn't be safer to send It perpendicularly to solar system to avoid objects?
No, the objects in the Oort cloud are incredibly far apart.
Can you explain Ice VII?
It's a crystal form of water that you can get when you compress it with 30,000 atmospheres of pressure.
Question: after recently watching the amazing documentary Farthest it got me thinking, do you ever get upset that you will miss all the future space discoveries and achievements that humans will accomplish past your lifetime
Absolutely, that's why I'm looking forward to my future robot body.
Hi @Fraser Cain ! I have a Schmidt-Newton telescope with 950mm focal length, 200mm mirror diameter, and a light polluted place, but stars are visible with naked eye. Currently (and for a long time) I don't have vehicle to transport it. Is it worth assembling here? What should I watch with it?
That's a big telescope, you should be able to see the planets really nicely with it.
Thanks for the answers :)
I'll assemble it, now I know it is worth it. It wasn't was assembled a long time ago, "becuse I wouldn't see anything, too much light". Not that long ago there was that mars event, and could see it with naked eyes. So I was a it skeptical. Now seems like I tought correctly I can see at least something :) What to assemble? The stands weight and counterweight system for a basic planed follower system. Then mount the optics to the stand.
The telescope was built by grandfather and a friend, the precision stuff (like the reflective coating of the mirror) was done by professionals at the national astronomy whatever. There was a program for average peoples to introduce them to amatuer astronomy, lead by Gyorgy Kulin the father of hungarian amatuer astronomy. If I know correctly he congratulated to my father and his friend that the mirror and other stuff are made so precisely. And the build cost? Basically for free. Raw materials? The company is ours, why not bring it home then (everybody stealed everything in the communist times). Manufacturing? Had a few friend in the company. Percision things? Funded by the program. The telescope is even compatible with 2 SLR cameras. Unfortunetly I don't know much about SLR, and don't have DSLR or anything that can be mounted to it.
Why didn't we used it before? That is a great question that haven't been answered in the last 20 years.
It wanted to try it, but it better to be careful. I couldn't contact the other person, and my grandfater is like "not now".
A recent study indicates that only a small % of earth-like planets are visible to earth or any other planet with current methods due to off-ecliptic alignment of most planets. The futility of hiding may rest on invalid assumptions.
You're talking about current methods. The LUVOIR telescope will be capable of seeing Earth-sized planets directly, out to dozens of light-years.
What are your current thoughts on space innovation such as space x versus NASA?
I think they both have their place. SpaceX is about the commercialization of space, while NASA's job is to take on the big risks that companies aren't willing to do.
Would it be possible to have non-mechanic reaction wheels by pumping lots of electrons thru a huge coil? How much of the weight of copper wires is composed of electrons?
You'd need those magnetic fields to interact with something. There are cubesats that can re-orient themselves using the Earth's magnetosphere.
No, I mean using the electrons themselves as reaction mass.
Highly impractical and perhaps impossible. I'm not sure why these reaction wheel seems to fail often. They should be very robust with magnetic bearings. There should be one rotating thing that touches nothing.
Is it possible that when you get to the singularity of a Black Hole, time actually reverses itself (going off the theory that going faster than the speed of light reverses time, or something similar) and that if all the Black Holes in the universe come together they either make an element so rare that it takes all of the protons, neutrons, and electrons in the universe to make that is also very radioactive and decays, making a new Big Bang. Or would it just rewind time for all the objects in the universe, because it is all the objects of the universe, then explodes for some reason or another, like an implosion/explosion grenade over and over again? (Sorry if this didn't make much sense, I'm very tired)
We don't really know what happens once you get inside the event horizon, but one idea is that the time dilation would be so great that you'd watch the Universe age and die right in front of you.
If the Arecebo radio telescope was at Proxima Centauri could it detect radio broadcasts from the earth? how about the square kilometer array?
I like this one!
Only if they were beamed directly there. They wouldn't be able to detect signals sent out in all directions because they'd be too weak.
What is your favourite space science fiction movie?
Wow, I don't have any specific one, there are just movies I like more or less.
Hey farser, i've got a question
Based on the size of the observable universe, do we know the rate of expansion of the universe?
And is it the same on every side?
This is known as the Hubble constant. Here's a video for you: ruclips.net/video/cw7MTOosfeU/видео.html
awesome as always Farser, thanks!
so, given that we know the Hubble costant, and we have estimates about the quantity of dark energy in the universe (even if i'm not sure if those are measured in joule or what) do we actually know how much energy is need to expand space?
Yes, astronomers know how much dark energy is appearing in every cubic meter of space.
"Conventional physics suggest it would take a quadrillion, or a million-billion, times more energy to form a microscopic black hole than the Large Hadron Collider is capable of, so even a third of that is beyond human reach". Frans Pretorius and his colleague William East detailed their findings online March 7 2017, in the journal Physical Review Letters.
Do you have a powerful amateur telescope? If yes, what's the smallest extraterrestrial object you've seen?
Nope, I don't have a good telescope. We have terrible skies here, so telescopes don't get a lot of good observing nights.
I always wondered what's the point of looking for extraterrestrial life in other star systems if we won't be able to directly study or interact with them for at least hundreds of years. And if we ever find an inhabited planet we would never be able to reach it in our lifetime.
We still don't even know if there's any life out there, so just answering that question is worth doing the work.
Q: what do you think about the movie life?
I haven't seen it.
Ok here's a hard one. If a cosmonaut can go inside a super massive black hole a live, would we be able to send an instrument, say a 5k mile long that is measuring every second and moment of itself and its surroundings... Since an astronauts is OK wouldn't said instrument be able to send information from inside the black hole from the parts not inside of it?
No, once you get inside the event horizon, you can't send out signals, since they're just pulses of electromagnetic radiation. Nothing gets out... nothing. It is pretty amazing to think that you wouldn't even feel the tidal forces as you entered the event horizon of a supermassive black hole, but still, nothing's getting back out.
Fraser, if a rogue planet was to approach our solar system how soon could we detect it and would it likely settle in orbit or.....?
We'd detect it once it started to distort the orbits of other planets in the Solar System. No, you wouldn't expect it to settle into orbit unless it went through some kind of three-body interaction with another planet that would put it into a new orbit.
I go for the "I don't care about my hair" look. I'm not bald, but my hair has thinned very much on the top. If anyone were to ask (no one yet has), I'd point at my beard and say that my hair had migrated.
Exactly, your hair fled to your face.
One thing that's bugged me, is that seti has a requirement of having a repetition of a signal, yet humans have never repeated a signal to potential aliens.
Not yet, but people haven't tried very hard to communicate at aliens. We're waiting for them to communicate to us.
Why is the speed of light so slow? What's holding it back?
It just doesn't want it badly enough?
Hello i wanted to ask you something, in end of juno mission the spacecraft is going to be crashed into the Jupiter why?
The same reason Cassini will be crashed, to prevent contamination with its icy worlds that could have life on them.
Fraser Cain how would it contaminate the moons,instead it would create new life if possible
"I would like to see a supernova like n+1 years ago that could be seen on the sky in daytime"
Goes out to watch some meteors (it was in august)
Sees moonrise first time (air was humid, little bit foggy, so there was a glow around the moon, can be seen before it risen)
Mind blown
Discovers that the mikly way can be seen with naked eyes
Mind blown
Uses binoculars, sees there is more stars in the "zoomed in" region, than in the naked eye
Mind blown
Maybe it is easy to impress me with sky and space stuff :D
And now you've got a telescope. :-)
Physics has a measurement unit for everything in the universe but doesn't seem to have one for rate of flow of time. 1 earth sec is 1 sec on surface of the earth but how do we define 1 sec on the surface of a jupiter-size exoplanet or at the surface of star? Also, what could be the fastest possible flow of time in the universe and how much would that be compared to earth time?
We did a video on this topic here: ruclips.net/video/JWncwRTMKkI/видео.html
Question: Here's the experiment, 2 atomic clocks, one placed inside a bubble, and that bubble inside a hollow spherical shell filled with superfluid helium. What happens if we use a magnetic field to spin the helium up to high speeds? Will the stationary clock in the middle of the high speed fluid read the same as the other, or will it read slower?
If it's moving, the two clocks will experience time dilation. But if it's just spinning, then only parts of it are moving compared to the other clock.
Nice V reference
Wait, that must have been unintentional.
I'd love to see Betelgeuse go supernova.
That would be pretty amazing.
What is your favorite deep space object, and why does it intrigue you as much as it does?
The deep space object I particularly enjoy M43. It was the first nebulae I viewed through my telescope, and the proximity to Orion constellation makes it very convenient to find. Nowadays, I enjoy solar viewing and planetary viewing while attempting to take nice pictures in my attempt of astrophotography.
So many, I really like the Ring Nebula - M57, and everyone knows I love the Rosette Nebula.
hey Fraser cain im visitin orlando in novermber. what do you think the chances are of me seeing a launch from the kennedy space center betweeen 1st-17th when im there?
If you do a search for Cape Canaveral launch calendar, you should be able to find a bunch of times that rockets are blasting off. I haven't seen anything in that window, but it could happen.
The only thing i can find is some thing about the spaceX heavy load scedualed for november 2017 but no actual dates. would be amazing if i could get to see an actual launch if not il still enjoy kenedy space center while im there. Thanks for the reply fraser
Quick question, I can't really find a good video about how planets get an athmosphere, so how?
My uneducated explanation would be that planets generally form around the same time as stars.
Before a potential star begins fusion, the majority of gasses would be in a solid state and would accumulate with other solids in the formation of planets.
When the star lights up and starts throwing about its energy, the gasses slowly warm and return to gaseous state, at which point they will already be gravitationally bound.
Great question, this article should answer it for you: www.astrobio.net/geology/how-rocky-planets-get-their-atmospheres/