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Accelerating Expansion of the Universe by Johann Encke - Thu, 23 Mar 2017 18:41:02 EST ID:pYbb5iMl No.56876 Ignore Report Quick Reply
File: 1490308862190.gif -(46487B / 45.40KB, 735x625) Thumbnail displayed, click image for full size. 46487
So if new space is created every now and then at greater speed and making them galaxies recede and shift to the reddest part of the spectrum, how much time until we're converted into a gaseous fading cosmic entity? How do we even perceive space? How would we perceive space expanding when it eventually gets fast enough to notice?
>>
Wilhelm Beer - Thu, 23 Mar 2017 19:23:33 EST ID:M/g1akbS No.56877 Ignore Report Quick Reply
This happens:
https://en.wikipedia.org/wiki/Heat_death_of_the_universe
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Johann Encke - Thu, 23 Mar 2017 19:32:19 EST ID:pYbb5iMl No.56878 Ignore Report Quick Reply
>>56877
that's just the end of entropy, which I imagine happens much later than the moment I imagine in my last question in my OP.
Would my hand turn red as it recedes from my point of reference?
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Friedrich Bessel - Thu, 23 Mar 2017 22:48:31 EST ID:7jcVAyVz No.56879 Ignore Report Quick Reply
>>56878
>>Would my hand turn red as it recedes from my point of reference?
No, because the law of inertia still holds, and your hand is still part of the object that constitutes 'you.' Same with whatever celestial body you happened to be standing on. Earth obviously wouldn't still be orbiting the sun at this stage, but if it were, all you would see in the night sky is blackness eventually, because even other stars would have redshifted beyond your ability to perceive them. But you would still see the sun during the day, because the earth and sun would still be part of the same inertial frame of reference, as would you and your hands.

>>How do we even perceive space
We don't. Space is a negative, we only perceive the absence of other things.

>>new space is created every now and then
That's not why space is expanding. The universe is actually an infinite volume, so there can never be any more space or mass, nor any less. It's actually the space in between space itself that is expanding, not that new stars and galaxies are emerging somewhere and pushing the old stuff out.
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Arno Penzias - Thu, 23 Mar 2017 23:58:42 EST ID:eYB2GzNH No.56880 Ignore Report Quick Reply
>>56879
wow, thank you. i'm now trying to wrap my head around the notion of space being a negative.
when would my inertial frame of reference be dissolved? or not even that changes as we approach heat death?
i know that space itself is expanding, so it is increasing distance between distances, right? not new stars and galaxies emerging, but the space between them pushes them farther from each other.
heat death would happen before molecular bonds break? or before atomic bonds break?
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Henrietta Levitt - Fri, 24 Mar 2017 00:04:42 EST ID:sOANcpac No.56881 Ignore Report Quick Reply
>>56876
>How do we even perceive space? How would we perceive space expanding when it eventually gets fast enough to notice?
Let's assume within the next year there was a hyper-expansion and everything expanded lets say a massive 10%. By the end of the year, the whole universe is 10% bigger in and out, you would be 10% bigger and the room you're in would be 10% bigger than in the beginning of the year.
If everything expanded, how would you know if anything expanded? Well, I don't know but I do think you wouldn't (unless you'd take measurements of the stretched out EM waves of the stars that you measured this year).
However I do wonder if that kind of space dispersion would have a perceivable effect on gravity. And if colours would change their shade a bit.
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Friedrich Bessel - Fri, 24 Mar 2017 01:29:43 EST ID:7jcVAyVz No.56882 Ignore Report Quick Reply
1490333383653.png -(61143B / 59.71KB, 840x2000) Thumbnail displayed, click image for full size.
>>56880
Thanks, glad I could help. The nothingness of nothing is actually much harder for people to grasp than you would think, I find that people believing in nothing as if it were something is almost a kind of pervasive cognitive error, so I think most people don't really get that, as obvious a thing as it is once pointed out.

Anyway, as you approached heat death, eventually the forces would become such that your body would be ripped apart and destroyed, but lets assume you could keep observing the universe from some cybernetic body that is only the size of a single point in space. In that case, your frame of reference would eventually disconnect from any other celestial bodies or objects, and would either fall into a black hole or just forever be in the void, with all other objects whatsoever forever inaccessible because they are all receding from you faster than lightspeed.

Yes, it is increasing the distances between distances, although it is also moving at an accelerating rate. However, it appears to have no curvature of any kind (the overall geometry of space time is flat.) So for example the space between all galaxies increases, but also to a very very small degree the distance between subatomic forces also increases. At a certain point, this means that molecular bonds can no longer form or be maintained, and thus all matter in the universe returns to an elemental state. Quite a long while after that, even subatomic bonds are predicted to break down due to acceleration, and will eventually break down one way or the other just by the process of nuclear physics, or ultimate subsumption into cosmic black holes. It is all indeed in the heat death chronology article if you want to get a sense for the timescales at which these things happen, or pic related.

>>heat death would happen before molecular bonds break? or before atomic bonds break?
Heat death is the absolute end state after all sorts of physical processes have completely come to an end. It is the moment just before the universe reaches a global temperature of absolute zero, which is special because it means after that literally no changes occur whatsoever, the universe is at 100% entropy. Thus, death.

>>56881
https://en.wikipedia.org/wiki/Metric_expansion_of_space
To make a long story short, we can tell that the space between space has changed relative to itself, and by what percentage, by using the fact that looking farther out into space lets us see further back in time to observe how space was then.
>>
Anders Angstrom - Mon, 27 Mar 2017 06:39:18 EST ID:e0oA2mYt No.56891 Ignore Report Quick Reply
>>56881
>By the end of the year, the whole universe is 10% bigger in and out, you would be 10% bigger and the room you're in would be 10% bigger than in the beginning of the year.

That's not actually true. Small objects like people and planets are bound by forces much stronger than the expansion of the universe so after a year the universe would be 10% larger but you and the room would be the same size.

>>56882
>Anyway, as you approached heat death, eventually the forces would become such that your body would be ripped apart and destroyed
You're thinking of the Big Rip, the heat death is simply what happens the universe tends towards thermal equilibrium long after the last stars have died.

The Big Rip won't actually occur in a standard cosmology universe because at very large times when the cosmological constant (dark energy) totally dominates the energy budget of the universe the rate at which the universe expands will be constant.
>>
Anders Angstrom - Mon, 27 Mar 2017 15:32:00 EST ID:7jcVAyVz No.56892 Ignore Report Quick Reply
>>56891
Technically, we do not yet know the ratio of dark energy's pressure to dark energy's energy density, so we cannot say for certain if the Big Rip will happen or not. Or if dark energy is even real I know it's not a part of heat death, I was merely including it in an overview of possible events in the very late universe.
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Chushiro Hayashi - Tue, 28 Mar 2017 21:52:28 EST ID:rYS5OuxM No.56893 Ignore Report Quick Reply
i once had it explained to me in a way that was really easy to understand

imagine if "space" was measured by an infinitely long ruler that stretched in both directions forever. then i said the ruler was going to expand. you might say "but its already infinitely long, how can it expand any more" and you basically just picture that the spaces between the markings on the ruler are expanding, regardless of the length of the ruler. its kinda like that
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Thomas Henderson - Wed, 29 Mar 2017 15:12:11 EST ID:F5zhng9P No.56895 Ignore Report Quick Reply
>>56891
>That's not actually true. Small objects like people and planets are bound by forces much stronger than the expansion of the universe so after a year the universe would be 10% larger but you and the room would be the same size
Hmm when I start to think about it, it sounds like true. UNLESS.. strong force, EM force and whatever force rules the higgs field decreases at exactly the same ratio as the dark energy 'puts in' so to say. Or something similar to this concept.

forgive me the rusty exhibits of these ideas I've been having some devil's juice and letting my mind spring on the topic of universe and astrophysics because science is fun
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Alan Guth - Fri, 31 Mar 2017 21:09:01 EST ID:OXINl/7g No.56900 Ignore Report Quick Reply
>>56895
The expansion of the universe occurs in such a way that right now, the distances between galaxy clusters is increasing, but the gravity holding the galaxies themselves together is "winning." The things within those galaxies (stars, planets, systems, people, etc) are far more influenced by the forces holding them together than by dark energy and the expansion of the universe. On a long enough timeline, it seems that eventually gravity won't be enough, but the strong/weak forces will hold on. Eventually, even those will start to give.

It's gonna be a while, though.
>>
Anders Angstrom - Mon, 03 Apr 2017 11:26:21 EST ID:RvXatVy3 No.56903 Ignore Report Quick Reply
>>56900
but as far as I've researched on the topic (and as far as my limited understanding goes) the formulae are yet not exact enough not only in order to decide if its going to be a big rip, a big bounce or heat death, but also they really can't calculate the nature of the time it will take.
ok, it's gonna be a long ass wait but as it progresses, will it be a log expansion? an exponential expansion? parabolic? no one knows.
i mean, once gravity is defeated by this force of expansion, how much more quicker will atomic forces give in?
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Mike Brown - Mon, 03 Apr 2017 15:06:53 EST ID:7jcVAyVz No.56904 Ignore Report Quick Reply
>>56903
Everything about the rip scenario is dependent on the nature of dark matter/energy. Specifically the ratio between its density and pressure, which may be positive or negative, or even zero (in the case where it turns out the dark substances aren't real.) The only real way we can differentiate between these cases is by getting actual observational evidence on this characteristic of the dark substances.
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Ejnar Hertzprung - Wed, 05 Apr 2017 14:49:04 EST ID:f/Tl+D5o No.56905 Ignore Report Quick Reply
I think there are beams of light and holes in the wall from the centralized spectral creation. We are one of the beamed holes, because we expanded from a such tiny space compression.
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Paul Goldsmith - Wed, 05 Apr 2017 16:12:44 EST ID:7jcVAyVz No.56906 Ignore Report Quick Reply
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>>56905
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Ejnar Hertzprung - Wed, 12 Apr 2017 00:12:46 EST ID:TSBuLBRU No.56910 Ignore Report Quick Reply
>>56903

how can anything ever overcome the force of gravity? isn't its reach limitless?
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Daniel Kirkwood - Wed, 12 Apr 2017 16:18:05 EST ID:7jcVAyVz No.56911 Ignore Report Quick Reply
>>56910
But it's power isn't limitless. Consider that the reach of the power of the sun's gravity is much stronger than the earth's, but because you are much closer to the earth, the sun's gravity doesn't pull you into it (well, it does in that it keeps the earth in orbit, but you see my point, that just because a force extends infinitely doesn't mean it isn't weaker at any given place than some other force.)


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