Q&A 26: Faster Than Light Into the Past?
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- Опубликовано: 26 июл 2024
- In this week’s Q&A, Fraser talks about black holes consuming dark matter, if traveling faster than light moves you backwards in time, and what those big pools under rockets are for.
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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 
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Thanks for giving me the opportunity to collaborate Fraser!
AstroFocus found a gem with your channel. Can't wait for the rest of ur Fermi paradox series.
AstroFocus thank you for answering my question! Exactly what i was looking for! already popped over and subscribed!
Joe Fraser thanks
Great channels! Lots of great stuff. I also got few questions for you guys:
It seems that every point in a space vacuum is litteraly filled with energy/light comming from all possible directions from all of the galaxyes/stars/planets/etc and should we even multiply it by the amount of angles that light sources was back in time? Could it be possible that vacuum is some kind of a source of unlimited energy because of this and we just need to learn how to use it? And also how all those rays does'nt cancel-off or multiply each other?
wrr
You might have misunderstood the question at 1:33 about a star getting so hot that it no longer emits visible light. I think the idea behind that question was about blackbody radiation and how things change color as they get hotter and if something can get so hot that it only emits light in the UV range and beyond. The answer is no, the absolute energy at a certain frequency does not decrease as temperature increases. So something that glows blue due to its temperature does not emit less red light than something that's "red hot." In fact, it emits _more_ red light but it emits so much more blue light than red, that it still looks blue to us.
You, my friend, Thank you.
This is what i meant, lol.
Penny Lane Thank you for answering this question!
Black Hole, you're very welcome and I'm glad you found my answer in all those comments :)
Honestly theres not that many comments in the first place
The other question is pretty interesting too. While what Fraser said is true about modern stars, it's actually thought that there could well have been direct gravitational collapses in the very early Universe, and these primordial black holes are a decently popular explanation for dark matter. They may also have been the original seeds for the supermassive black holes at the core of galaxies.
7:30 If I may make yet another dark matter comment: There's a great deal of variation in the proportion of dark matter that galaxies contain. We have seen galaxies that contain almost no dark matter and other galaxies that contain about 100:1 concentrations of dark matter.
Dwarf galaxies in particular often have very high concentrations of dark matter. MOND's failure to accommodate this observation was one of the things that led to it falling out of favor.
PDM handles the amount of variation that we see naturally while other dark matter theories have difficulty explaining it.
Fun fact: Fraser Cain used to have a full luxurious head of hair, but it was abducted by aliens.
This is sad but true. I've even posted a picture of it in a past episode of the QA.
as they say fraser that grass doesn't grow on busy roads....
This was a very informative and interesting video. Thank you for making it.
I like these q and a's, keep them up.
Thanks! I like doing them. :-)
thank you for answering my question!! :D
Thanks to Astrofocus.
Fraser Cain already thanked him and subscribed!
great stuff, tyvm.
Thank you Fraser for sharing your immense knowledge, you're truly a LEGEND
I believe the second question was oriented towards wien's law, which predicts the wavelength of the peak of emitted radiation by a black body. What "black hole" was asking is if a star could get hot enough to radiate most of it's energy outside of the visible spectrum, making it appear black or not as bright to the naked eye.
Subscribed!
Thanks, welcome aboard!
Hi Mr Cain, just found your channel. Love your enthusiasm....same as your podcasts with Dr Pamela Gay. I've just found my new best channel!! Your standards of content are captivatingly high, don't know how you have time for all your work. Thanks for all the info you bring to us.
Thanks a lot, I'm glad you found it. I don't have time for all the work, which is why I have Chad. :-) The editing takes a lot of time, and I couldn't do it without him.
Fraser, have you considered doing a video about what's happening in the night sky in the coming month? This is so we know what to look for and where in the sky it will be.
Here's hoping.
Thanks for your great educational work and keep it up! Colin
I have thought about it, and we even published a book for what to see in the night sky this whole year. But I find that material is more useful in text form where you can provide a nice list.
First off, thanks for letting us know about AstroFocus! Gonna have to go check his channel out. :D
I think that question about faster-than-light and time travel was referring to the problem of potentially violating causality by sending information between observers moving at relativistically different velocities. You would still get that problem if you had an FTL ship making the trip instead of an instantaneous signal.
3 questions:
What planets in our solar system will be habitable in the far future?
Can it be humans lived on mars in the far past?
Ooh and 1 final question do you think we lost a lot of history of the past of humanity?
Since there are a lot 'out of place objects' found around the planet.
Wow , always wondered how We figured out Our place in the Galaxy when We're looking at It edge on . Thanks , I will look at this other channel that explained that :)
You made a slight mistake on the *Dyson sphere question.* It is not so much that we can't capture all of the energy of a star and prevent it from escaping, though I'm sure reaching anywhere near 100% efficiency would be a challenge, but the problem is overheating. Energy can't be destroyed or created and energy = heat so the same holds for that. Keeping all that heat trapped would get everyone in the sphere cooked, and rather quickly. That is why heat has to be released and why a Dyson can't hide.
Great point.
Thank you. :) Some more context for other viewers, energy out needs to equal energy in that means the Dyson needs to radiate the same amount of energy the star would have. This means that a Dyson would be this giant sphere that would be relatively cool. Cool enough to be a brown dwarf or a giant planet yet its size would dwarf that of a star. This would be a dead give away that it is a Dyson sphere, too cool for a star, too huge for a failed star.
Something I want to say... When I leave a comment on this channel, I do it with pleasure, and I hope to "add" to the rest of what you (Frasser Cain) is saying. Most other channels, I feel like I am "correcting" what the host is getting wrong, and that makes *all* the difference!
Aww, thanks, that means a lot to me. :-)
You deserve it!
Fraser :-) I am struggeling with 2 competing concepts about time travel. You just told us that leaving earth and travelling beyond light speed would only adjust your time perspective to light rays that left from your departure location and that if you turn around and went back you would unwind the apparent time shift and get back after you left without any time shift except the local time where you left. On the converse we are told that if you take an atomic clock into space and leave one on Earth the one in space will get slower than the one on eart due to the speed of travel and on return the space traveling clock would be behind the clock that stayed on Earth. Also that the space flying cloc would get more behind if it had travelled nearer the speed of light. In fact I heard that you would age slower at near light speed and get back to earth younger than your twin who stayed behind. These two concepts seem to conflict and I would love to know what is true. Tks :-) Astro B.
Astrofocus: Is this a young boy? If so: bright guy!
Yeah, he's got a bright future. So talented, so young.
Can a universe with no matter in it be observed? If nothing exists that can observe, is the universe observable? You're right - this *is* mind-bending.
I was just thinking about time travel to the past this morning!
Whoa...
Hey! Seeing into the past is “possible”?! That’s good enough for me!
Yeah, it's one of the big advantages of being an astronomer.
It is difficult to explain, but roughly, I think we live in a white hole with time inexorably moving forward, but the black holes rip that continuum and matter that is sucked into black holes "fall" back to the big bang because that becomes the only barrier to the matter as it doesn't experience the time dimension anymore. That then becomes the matter that makes up the universe as it explodes out from the big bang. It's all a self contained loop that takes advantage of the infinities created in both kinds of holes.
Thanks! Grazie!
Another great program! Yes, thank you for clarifying SETI. It appears to be greatly misunderstood by Stanton Friedman (well intentioned but deeply flawed research). Hey, I wish people like you could be our astronauts!
Thanks, I'm glad you enjoyed it.
Not only that, but remember that matter is energy and vice versa, and dark energy definitely counts as part of that equation. According to most modern cosmological models, Dark Energy is always increasing because space itself is increasing which means the total energy is increasing as well (just enough to keep the universe flat). Strange but (apparently) true.
We're not sure, though. We don't know how dark energy relates to regular old energy. It's still a total mystery.
Thanks for the answers!
Speaking of the Oort cloud, I do have a question in that vein. Is it likely that such icy body collections are common in other systems?
Additional question. If we measured local gravity with fine enough resolution, would we theoretically be able to detect the loss of gravitational influence of say, supermassive black holes as they near and slip over the cosmological horizon?
Hey if you listen close to the speakers, you'll hear forest sounds! Great episode btw, thanks!
Yeah, the microphone is actually not that bad. When the forest is really loud, we think it'll get picked up, but it's not too bad.
It is good I think, not bad : )
Great show Fraser. What's your answer to the concerns about the space version of the law of the jungle and suggestion that we should stop sending signal to alien and hide forever instead?
Question for Chad: Do you love what you are doing? If there is an offer from big TV producer to work their product, are you quit? (Please say no :D I love this channel and all of your work. You work awesome together :D)
Since the Alcubierre Drive violates causality when used to travel faster than c, would it work for traveling up to the speed of light in a very efficient (relatively speaking) manner?
as the universe is expanding faster then the speed of light is it possible for a collision to occur at these speeds? are there inconsistencies in this acceleration?
Hello , isn't it possible to detect some dark matter inside the solar system by looking the planets behavior around the sun like we do with star around galaxy center or is it to tiny or just did n't have impact in the scale of the solar system ?
In this smallest level, we can't detect the gravitational effects.
Hello first of all i like this channel i watch this every night before i sleep is there is something different than radio waves we can broadcast. I hope i get a answer
Regarding going faster than light to see the past. In the book series Frontier Saga the do this several times.
They go out a couple of light hours an watches them self a few hours ago.
That would be very strange to see. :-)
I read another SciFi book where someone gets ejected into space and somehow rescued. Other than having lurid red eyes and some frost bite, they are fine.
My question is: Shouldn't they get what scuba divers call "The Bends"? Surely, the nitrogen in our blood would boil off and the dashing hero would be a pain wracked crippled mess. I only ask because I was contemplating applying for a job as a intergalactic hero...
Great video as always : )
Something that I think can help one understand the size of things, Oort cloud and Galaxy, is the game "Elite Dangerous". It's worth the $20 just to see the galaxy map and zoom in and out...totally mind blowing. And I've known the size of our galaxy for 40+ years as an amatuer astronomer, it's mind blowing! It's also a very accurate simulation of known astrometric cartography.
I thougt at any frame of reference at any speed, light always travels at the speed of ligth relative to you
Some questions were genuinely intriguing but a lot seemed to stem from people not understanding how energy works and how mass gets converted into energy through processes like fusion or fission. It just made me think they should research a little before asking.
Keep in mind that this is a journey for most people, with a lot of pieces that need to go into place before they can start to understand everything. So I try to include some of the more basic questions with some of the more complicated ones.
Is there dark matter inside of galaxies or is there some kind of force that keeps it out as a halo?
The galaxy that we can see is stuck in the middle of a vast cloud of dark matter. It's inside the galaxy too.
One basic thing about Fussion that is missed by most people is the fact that when the Universe formed **matter**, it stored the RAW energy down into what formed atoms, and all other forms of matter. In fact, this was a very wasteful process, also governed by the Law of Entropy, and the result of matter in the Universe is analogous to our limited (and far less time involved in) fossil fuels, which is a fuel that only gives up so much to its environment, but takes massive amounts of energy to create. The payout of Fussion IS much higher, but the amount of Energy that the Universe put into the even that created matter was unimaginable, too.
Hey, I've been wondering this for a while, and having recently seen your video on neutron stars and quark stars, I thought it would be a perfect time to ask. I was wondering, saying that string theory is true, could there be a point just before becoming a black hole where those particles in the star could become compressed down to their individual strings? Or possibly that a black hole itself is a "string star?" Let me know what you think!
The question about stars turning black wasn't about gravity! It was about stars being so big and so hot that all of their radiated energy was above the visible spectrum.
I have a question do solar panels create power by harnessing the light or the heat from sunlight it receives?
They convert photons of visible light into electricity.
2:54 .. He completely misses the Ball .. His question pertains to , once you REACH the SPEED of light , your CLOCK STOPS TICKING . so if you go faster would it start to run backwards ?
( possibly ) (( i have thought about that also ))
My favorite channel to watch while high. I only wish you posed 3 videos per day
Saleem Says posted*
while sniffing glue*
Jamaa L why correct the man? He is apparently high.
Regarding Cythil's question about FTL and time travel: There are causality violations involved with FTL en.wikibooks.org/wiki/Special_Relativity/Faster_than_light_signals,_causality_and_Special_Relativity - I don't pretend to fully understand this but I've seen it explained though many sources. I believe Robert L. Forward explored this a bit in the novel "Timemaster" also. Personally I find it easier to disbelieve the possibility of FTL than to believe in the possibility of time travel - you can't have one without the other.
That said the time scales are very small unless the distances (and relative destination velocities) are HUGE, perhaps even intergalactic (?)
Hey Fraser, sorry if you've already answered this question but if one were to get caught in a black hole's gravitational pull could they escape and if so how?
• iCaprica - if you are in a spaceship and have fuel just head in the opposite direction with a higher force than the gravitational pull, should be no problem
Hi Fraser, I have a question for your episode on horizons. Is there any currently known bounds to the size of our "reach-able universe"? As in, if we started travelling at .9999(etc) the speed of light today and sent out ships in every direction that had a star/galaxy we can travel to, how big is the area of the observable galaxy that we'll be able to reach? I figure it's probably related to the future of dark energy, whether it increases, decreases, or stays the same, but even without knowing that truth I'd hope there's still some estimated upper/lower bounds for our "reach-able universe".
Random question about Saturn. With Juno whizzing around Jupiter, we hear a lot about the massive doses of radiation that Juno has to deal with thanks to Jupiter's magnetosphere. Is this not a problem with Cassini? Does the massive planet Saturn not have a similar radiation issue?
Hi there Fraser. How is it possible for our universe to have a finite age and possibly infinite size? Wouldn't it have to expand forever to be infinite?
Hi Fraser, I have a question that I would like you could answer in a video.
Q: Today we don't know if the universe is infinite or not. Could we use a bigger gravitational wave experiment to know where is the farthest black hole collision and use that to size at least our part of the hypothetical multiverse?
Thanks!
Hey Fraser, how long will it take to reach to the edge of observable universe if we travel with the speed of light or say 99% of speed of light? Will it still be 13.7 billion years or will time dilation and distance dilation will play a role in it?
Here's a video we did about this. ruclips.net/video/4tjQ8o8j-O8/видео.html
A few videos ago you talked about mining the solar system for resources. If you completely mined the gas and ice giants, wouldn't the mas distribution affect the rest of the planets and objects in the system in a potentially negative way?
You said any question... how about this... What would happen if we found alien bunker on Mars?
Suzaku455 People would still believe religions are real.
attack what would be the contradiction?
Ok, some valid points about religion, but not for the Christian thing. Tech has only one connection and that is to war. Usually, the victor of a war is tied to the technology it has, which if you think that religion is responsible for... well, then stability is connected to those that are willing to do anything, which fails to bear any credit to religion. Science on the other hand, allows some men to invent technology used in wartime, which determines the outcome of wars in most cases. Anthopology has taught us that the connections to societal theology are ubiquitous in nature, and have no direct bearing. Vikings, the Monguls, and various others, early Romans (Alexander the Great), and the Greeks... none of them are Christian, but held a higher knowledge of things that gave them an "edge" over others; For THOUSANDS OF YEARS.
A question about space expansion, If galaxies that are farther away from us move faster away, doesn't that mean that they were that fast a long time ago? Can it be that at present time the expansion rate of that galaxies slows down, but we just don't know about it, because the light from them haven't reached us yet? May be galaxies closer to us are moving slower because information about them updates more quickly? and the whole universe(visible) is slowing down in expansion.
For the next questions show: so, the smallest stars will live for trillions of years, right? could an advanced civilization store nebulae by condensating them into planets, and at the end of their star's life, just fuse a bunch of those planets into a new star and live off it for another trillion years?
Sure, we talked a bit about how you could save the Sun this way: ruclips.net/video/uDp9oPVjJc0/видео.html
Hi Fraser!
Considering time dilation, would an object moving at c claim to simultaneously be at its place of origin, its destination and everywhere in between? I'm not literate enough in physics to know for sure but it's something I've always wondered.
Sir I wanted to ask that CAN CONTRACTION ALSO REVERSE TIME
A fusion reactor isn't a perpetual energy device since you have to add fuel. As soon as you do, the source of fuel becomes part of the system as far as thermodynamics is concerned. (Eventually the system becomes the entire universe)
would it be possible to take a picture of a planet in Alpha Centauri and see the surface details. I imagine thers a limit how detailed image we could get from certain distances because of the amount of photons.
Re dark matter: in the current issue of Scientific American there's an article discussing if Dark matter may be primordial black holes. It seems to be consistent with the LIGO results.
Wow what an excellent q and a channel. Could I ask why of all the forces.... why is gravity so comparatively weak? ...further more why does gravity exist?
Hey Fraser! What if I cool the outer shell of the Dyson sphere, with like a heat pump and pump the use the energy or some other way? I can put the support equipment into the same way cooled thing and it would be pretty close to cmb.
Where are you going to pump that heat? If you don't radiate it away, you're going to cook.
Fraser Cain the laws of thermodynamics state that energy can't be destroyed, it da only change forms. To keep yourself from getting fried you would either need to use all of the energy that the sun puts out or you would have to vent some out.
@Fraser Cain The point of the Dyson sphere is to convert things that make the sun, to more usable energy. The sun makes a lot of heat, soo the same: Convert it to something else, and you it where and when it needed.
It probably won't be a perfect system, but who needs it, the basic civillization don't have good enough gear to detect it, more advanced ones find out somehow, like look into a telescope and see spaceships docked on the charger which is charged from the heat and light, etc energy of the sun, and that "little bit" heat energy from the outer walls.
Hey Fraser! Thank you for taking the time to answer questions. My question. If dark matter makes up roughly 23% of the mass in the universe, why can't we find evidence of it in our solar system? The same for dark energy. Why can we not find evidence of dark energy in our solar system?
1:00 Despite disagreement on dark matter theories, all the particle-believing astronomers you've talked to believe black holes would consume dark matter.
Comment: It's not just them. PDM, the non-particle theory that I favor, *also* predicts that black holes would consume dark matter. In PDM, dark matter is just like visible matter, just there are 6 lanes of matter and electromagnetism doesn't cross between them but gravity does.
MOND, however, does not, MOND being a theory that just alters the law of gravity to fit galactic rotation curves. Not a lot of people favor MOND nowadays.
I would like to see you do a video on the possibility that there was a planet between Mars and Jupiter that broke apart and created the asteroid belt!
Like this one? ruclips.net/video/-BMoD7k7q4o/видео.html
Greeting Fraser. Concerning Vacuum Decay: what makes us suspect the Higgs field might be unstable? and could we inadvertantly do anything to start the chain reaction? and could it have started elsewhere in the Universe already?
Question: If we detect alien radio broadcast (For example their live broadcast sport event) is there any market to listen them with large radio telescopes and start a service like Netflix? What do you think about humans think about alien broadcasts?
I heard that dark energy might be vacuum energy. If so, why is it pushing stuff apart and not pulling it together like matter does (E=mc²)?
I have a question. We assume that absolutely nothing can go faster than the speed of light. I learned in college that how denser an element is, how faster the speed of sound travels into it. Now, let's imagine you can land on a black holes center and you decide to hit it with a hammer. Knowing that the black hole is extremely dense, what would be the speed of sound in it? Is it possible that the speed of sound can equals or even exceed the speed of light in extreme dense elements?
Could a telescope show stars, constellations and galaxies disappearing from view as they reach the event horizon of the observable universe, or is the process too slow for us to see?
dark matter is a weird term, isn't it more like dark gravity?
couldn't we just have way more black holes than we thought... we can't see those either?
I think you misinterpreted the question about stars becoming "so big we cannot see them." The question was basically, can a star become so hot that the light it emits has a wavelength shorter than visible light. It's not a question about gravity, it's a question about blackbody radiation.
If dark matter doesn't react to normal elements or particles could we use it to create free energy?
We still don't know what it is, but I'm going to assume that even when we do, it's not going to violate the laws of thermodynamics. There's never any free energy.
But you never know. There are always things in science that we thought to be absolute that would change later. That's why I feel that what we know about the universe is only a very basic view. Compared to monkeys we are incredibly smart, but there must be some civilization, or just thing out there smarter than us who can understand things our feeble minds cannot.
That is why I believe that our idea of a "God" is just our feeble minds trying to wrap our heads around it. If there is a god, which there may be, who says that it can't be another civilization from another universe that created us. Or some being, or thing that we could never imagine in a 1000 years?
Q: with space tourism coming up in the near future, what is your opinion about this statement:
"the energy needed to get tourists a spacetrip (for example beyond the moon), is completely out of this world and therefore totally irresponsible / unacceptable"
Many articles about this subject talk about rocket fuel details, but tend to ignore the energy needed to produce this fuel (like 'superclean' hydrogen and oxygen). This energy is probably taken from normal power plants generating lots of CO2.
is the ort cloud part of the solar system? Or more of the defined edge of it?
It's under the influence of the Sun's gravity, so I'd say it's still within the Solar System.
I don't know if I agree with you concluding that Dyson Spheres would leak energy. That energy was once their suns mass, who's to say they don't convert that energy back into mass. I know the 2nd law of thermodynamics says there's always a loss. But lossless systems aren't any more implausible that a Dyson Sphere lol.
Especially when you consider quantum mechanics, every bit of energy is a discrete packet based on the Plank unit of energy. You could, in theory catch 'em all =)
If you trap heat, then you get hotter. Even if they have some way to turn heat into matter, there's going to be some kind of loss, otherwise they build a perpetual motion machine. At some point, heat needs to escape.
I have a question, more of a concept that I want justified or explained.
Really enjoy your channel BTW.
OK traveling at relativistic speeds slows time down. At the speed of light does a photon experience time?
From the point of view of a photon would you see all of your existence instantly or would your existence seem like all of time?
There was another video I saw somewhere that explained that the travel time would feel instantaneous for a photon. On a related note Fraser Cain may not have understood the "faster than light question" for this very reason. If time slows down the faster you go and stops at light speed, will it actually reverse beyond light speed? This might be the reason the cosmic speed limit exists because you can't go so fast at all without being sent back through through time to where you started, forming a paradoxically impenetrable barrier to faster than light speeds. Also, If falling into a black hole means falling faster than light past the event horizon, I propose it is impossible to pass the event horizon because of the "anti time" within. You would only get smushed there. This fits well with how special relativity predicts matter to compress 2 dimensionally as it approaches light speed.
Ref: exoplanets. I read that it takes 3 orbits (or transits) to verify the existence of an exoplanet. It seems that most of the "earth2" discoveries so far are relatively short period planets. To find an exoplanet with an orbital period of 1 year would take 3 years of observations. Do we have this depth of data yet but are still crunching it to sift out exoplanet candidates or haven't we had the observation time available to focus on sufficient stars for 3 years straight yet?
If positron is an electron moving backwards in time, does it mean that it travels faster than light?
I think the question about time reversing past the speed of light has with the notion that photons (traveling at the speed of light) don't experiense local time, so taking that a bit further, wouldn't an object moving fasster then the speed of light also experiense reverse time? The question isn't about the moving, but the bending in spacetime that the moving would cause.
Can we know if a star we think is not very bright since the moment we saw it for the first time, it is so because of a structure built around it?
how does a cube sat work with photon propulsion if the laser is mounted to the probe? if the launch platform remains near earth how would we over come orbital dynamics and diffusion over really long distances?
The laser pulse would only be able to work for a certain distance. After that you'd need more satellites deeper in space to keep accelerating the spacecraft.
I've got a really good question. if you were accelerating and travelling towards the speed of light, would harmless visible, ultraviolet light blueshift to harmful xrays and gamma rays as you accelerated faster and faster? as you travel in any direction in space, you of course travel into all kinds of electromagnetic rays.
With currently active technology (things we are using right now) how long would it take to travel a light year?
Fraser, time dilation is dependent on inertial acceleration. One might accelerate up to relativistic speeds to experience relativistic effects. But if your reference frame were to move you at relativistic speeds relative to another reference frame, one would not experience time dilation relative to either. Right? And if your reference frame moved you out of the light cone of another reference frame - while you stood still within your reference frame - since there would be no time dilation effects due to inertial relativistic velocities - what kind of effect might that have on shifting time between reference frames? Your spacial reference frame moves out and then back into another reference frame's light cone. Does that suggest time warp or not?
Question: Can gravitational waves escape from balck holes?
That would be so cool to see the past.I hope its somehow possible to go faster than the speed of light.
Thanks for the great videos. You mentioned stars could get much more massive in the early universe, what was different about the early universe that made this possible?
Morgan Morningstar - all stuff was closer to each other, the universe had not yet expanded to the size of today
That doesn't explain what I am asking. Just because things were closer together doesn't explain the physics behind it and why we do not see stars over about 200 solar masses today. If you could clarify, it would be appreciated.
Morgan Morningstar - ok, sorry, i have no idea, only reading comments etc, I find it logical that an earlier / smaller universe give us denser clouds of hydrogen and then larger stars but I think this requires someone with an education, sorry again
Hi, love these Q & A videos. I have a question, looking at the sky and the Milky Way it looks tilted from our point of view. Is our Solar System tilted w.r.t. the plane of the Milky Way Galaxy?
Here's a video we did covering this exact question: ruclips.net/video/5TDXuoV-oQU/видео.html
Thanks for the prompt reply..watching the video now.
Fraser, since Earth's rotation is slowing, at what time frame will it stop and what will be te biggest impact from this?
I think the question about the size of a star that doesn't emit visible light was misunderstood. I think they were asking what would the theoretical size of a star be that's so hot it shines in the ultraviolet. You answered that this wouldn't be possible, but is there a way to calculate it mathematically?
Even a supermassive star that's blasting out x-rays is still going to be producing lots of visible photons too.
Is it possible for a star to be made of electrons only, in the same terms that we have neutron stars.
No, electrons and protons are squeezed into neutrons. If you get an object that's dense enough, that's what it's going to do.
Frasier, I think the question about the going FTL was actually about the lorentz transformation becoming negative. Meaning your local time with the transformation becomes negative, or backwards in time. Can you comment?
You forgot to put "and more...." at the end of the title!
Good point!
what is the best way of disarming a volcano?
drilling pressure valves?
and how to prevent earthquakes and tornadoes?
(traveling FTL), so if you arrive at the destination and can see further back into time than when you initially set off, then how would it not be the case that if you made the return trip, you would be able to look back at the destination planet and see it even further back. While I agree that space was traversed, if you think about spacetime together, than since your light path is facing the other direction, your time path must also do the same. So if you look back and see further back than you're supposed to be able to, how is that not because your time\consequence cone has been shifted into the past. And if you look even further back, you should be able to see light that previously escaped your cone, which technically puts you into the past, does it not?