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Old 03-25-2012, 01:49 AM
 
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Originally Posted by Brian.Pearson View Post
I'd say it's not likely such black holes would exist forever. The research in the article figures that supermassive black holes were full grown when the universe was less than a tenth of its present age. Let's be generous and say it was one-tenth. That means these black holes were full grown when the universe would have been about 1 to 1.37 billion years old. Matter would have not spread out as much as it is today. These black holes would have had plenty of material to feed on to get so large in a relatively short period of time. I wouldn't be surprised that mergers of black holes could have been more frequent early on as well, with smaller ones providing more mass to the bigger ones.

We are living in the age of stars and galaxies. If we assume that the universe continues expanding, stars and galaxies would die out and usher in the black hole era, because that's pretty much all that would be left of any large structures. With nothing to feed on, black holes would slowly evaporate over an incredibly long period of time. Hawking Radiation is thought to be very faint, but it would still decay from the black holes losing mass, even though extremely slow.

So, would it be possible supermassive black holes so be so big that they'd never dissipate? No, in all likelihood, they too would eventually die. Again, it assumes that the universe would continue expanding to eventually reach heat death of the universe, the Big Freeze. After the black holes are gone, there may well be photons still on the move, but they'd ultimately be scattered so far apart that their paths would rarely meet, if ever. It's unknown just how long they can exist.

It's also possible that the universe could end with the Big Rip scenario. If that should happen it would occur in less time than the Big Freeze, but it'd still be a very long time from now, perhaps 22 billion years from now. Everything would gradually 'rip' part. Black holes would still face their eventual demise.

Ultimate fate of the universe - Wikipedia, the free encyclopedia

Future of an expanding universe - Wikipedia, the free encyclopedia

Heat death of the universe - Wikipedia, the free encyclopedia

Big Rip - Wikipedia, the free encyclopedia
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Old 03-25-2012, 09:08 PM
 
Location: Texas
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Could you touch on phantom energy?
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Old 03-25-2012, 11:37 PM
 
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Originally Posted by Brian.Pearson View Post
Could you touch on phantom energy?
It's a hypothetical version of Dark Energy and assumes that Dark Energy is Phantom Energy. The idea is that it's everywhere and increases in the acceleration of space. As it continues increasing in strength, it could become so strong that it begins tearing everything in the universe apart, including all galaxies, stars, planets, atoms, etc., because of the ever forceful increase of all space. At that point, it would pretty well be of the final chapter of the universe entitled "The Big Rip".

[astro-ph/0302506] Phantom Energy and Cosmic Doomsday
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Old 03-26-2012, 12:45 AM
 
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It can not only show you the wonders of the Universe; it can also let you share these wonders with those who are close to you.
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Old 03-26-2012, 09:41 AM
 
Location: Texas
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Originally Posted by NightBazaar View Post
It's a hypothetical version of Dark Energy and assumes that Dark Energy is Phantom Energy. The idea is that it's everywhere and increases in the acceleration of space. As it continues increasing in strength, it could become so strong that it begins tearing everything in the universe apart, including all galaxies, stars, planets, atoms, etc., because of the ever forceful increase of all space. At that point, it would pretty well be of the final chapter of the universe entitled "The Big Rip".

[astro-ph/0302506] Phantom Energy and Cosmic Doomsday
Seems to me if everything was being pushed at a continuous rate, then everything wouldn't "notice" this. In other words, each molecule would be pushed at a continuous rate, so there would be no rip.
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Old 03-26-2012, 02:50 PM
 
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Originally Posted by Brian.Pearson View Post
Seems to me if everything was being pushed at a continuous rate, then everything wouldn't "notice" this. In other words, each molecule would be pushed at a continuous rate, so there would be no rip.
Not necessarily. For molecules to continue functioning, they'd probably have to be pretty much as they are right now. That's not likely to happen in a Big Rip scenario. If the Big Rip would increase rendering Gravity completely useless, there's no reason to think it would slow down. It'd continue getting exponentially stronger and overwhelm the other fundamental forces as well. Keep in mind that the Big Rip would be happening to everything everywhere at the same rate. It might start out slow and unnoticable, but it'd happen pretty fast as it picks up.

Assuming life is still around in the far future, and perceptions are the same, you might experience a brief sense that something different was happening, maybe similar to feeling dazed and confused just before lapsing into a state of unconscious. Clearly, if the atoms in your body were becoming disassembled, it might not be painful, but every part of you wouldn't be working right. It'd be over very quickly. I would think you wouldn't notice it. You could be in mid-thought about something, then it all instantly stops.

The thing about the Big Rip idea, is that at least part of it stems from the view that following Inflation, as the Universe began to cool, the expansion began to slow down. It was thought that the Universe was still slowing down, but unexpectedly found the expansion was actually speeding up. In very distant regions of the Universe, galaxies appear to be so severely red-shifted that they must be moving away faster than the speed of light. It's not that the galaxies are actually moving that fast, but rather that space itself is expanding to cause that fast causing greater distance between those object and us.

So now we have a view that the Universe did slow down for a while following the rapid inflation, which makes sense, but the expansion began accelerating faster about 5 to 7 billion years ago. The only thing that seemed to offer an explanation was Dark Energy. As Dark Energy creates more space, it also creates more Dark Energy which in turn seems to be causing the universe to expand at increasing rates.

I'm not sure if that's what's happening, or whether it could be some kind of illusion that only appears to make it look that way. The Universe is a pretty strange place. The general concensus seems to lean toward the view that it is indeed an increased rate.

The idea behind the Big Rip (as I understand it) is that if Dark Energy (Phantom Energy) is at work and permeates all of space, not only at the macro scale of the universe, but also at the quantum scale, then the space between the nucleus of atoms and the electron shells, may also be expanding. If the expansion also includes the space between particles, and the expansion rate continues to rise exponentially, then the atoms themselves could eventually be ripped apart. If that's how it would happen, then the Universe would be doomed in a 'short' 20-22 billion years from now.

While the hypothesis that the Universe will die from the Big Rip can't be completely dismissed, there are some other views, although I don't think they've been conclusively determined. One of those ideas is that the Universe might go through stages in the rate of expansion. That is, there may be periods when space expands faster and periods when it can slow down, perhaps somewhat in cycles. If that should be the case, then I would think it'd be likely the Universe would end with the Big Freeze scenario.

Another view seems to suggest that the expansion of the Universe might already be slowing down again. I'm not sure that view is widely accepted though. Even if it is slowing down, the Universe wouldn't likely contract and collapse in on itself (Big Crunch) because the overall size of the universe doesn't seem to have enough stuff and what it has is already spread out too far for Gravity to reverse the expansion and cause a collapse.

Whatever happens to the Universe is so far off in the future that there's no real telling what will occur. The Universe could do something else completely unexpected. Who knows? It'll do whatever it does regardless of whether our current predictions are correct or not.
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Old 03-26-2012, 09:59 PM
 
Location: Texas
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I just feel intuitively that Dark Energy would continue to speed up. And as Dark Energy pushes galaxies or any other kind of matter, we would just gradually move to another frame of reference without actually sensing a difference. Call me stubborn.
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Old 03-29-2012, 02:29 PM
 
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Originally Posted by Brian.Pearson View Post
I just feel intuitively that Dark Energy would continue to speed up. And as Dark Energy pushes galaxies or any other kind of matter, we would just gradually move to another frame of reference without actually sensing a difference. Call me stubborn.
Whatever way it happens, it'd definitely be a different frame of reference. Whether the expansion would remain gradual or not is unknown. Our view that change at large scales in the universe happen so slow that we can't perceive it without extremely sensitive equipment. As such the process appears to be very slow. Such a view of structural stability is due to our view of relativity from our point of view as observers. For example, if we stand by a road watching a car speed by at 100 mph, we perceive the event as being very fast. But we don't readily perceive that the entire planet is spinning at about 2000 mph, and that the speed of the planet orbiting the Sun, or that the entire galaxy is spinning, are at greatly faster rates. We often think of mountains as being pretty sturdy and unchanging, but then Mt St. Helens certainy showed how something like that can drastically change in a matter of moments. Our point of reference, with regard to perceptions, is based on the things that are around us and the relative motion of those things. Nothing in the universe is truly stationary.

Without "stuff", there'd only be empty space with no points of reference for comparison. No motion to observe, nothing. If you could somehow be placed into such an empty universe, you might be drifting around at incredibly high speed, but you might just as well be motionless as there'd be nothing around you to determine if you're moving or not. It's because of the matter in the universe that we're able to have such a frame of reference.

That doesn't necessarily apply to the space of the universe though, which I think is fair to describe as being present at macro and micro scales. It's everywhere. There may be exceptions at Planck scale though. We also have no real idea of what the universe and the expansion of space may or may not do. If the expansion continues at the rate as it appears to be doing without too much disruption of the fundamental forces at local scales, then even though space itself expands at ever incrasing rates, we wouldn't perceive it because not only do we have to consider the relativity of increasing space, but the relativity of increasing time.

On the other hand, since we are products of the universe, it's pretty hard to conclusively say that the expansion must follow along with how we think it should. The universe and the expansion of space could well through an unknown and unexpected curve at us. There are lots of possibilities of what the expanding universe could do. For example, following the initial 'spark' of the Big Bang, the growth is thought to have been many times faster than the speed of light in a very short period of time in what is considered a period of inflation. During this inflationary period and ever since, the universe began to cool as space continued to grow. As it cooled, the rate of expansion began to slow down.

From an historical perspective, sometimes what we consider as intuitive can be completely wrong. It was thought that the space of the universe was endlessly expanding at an ever slowing rate. Instead, we discovered an unexpected twist. The expansion of space has been speeding up instead of slowing down. It went from fast to slow to fast again. The only explanation is that something must be driving the expansion of space. The suspect is what is called Dark Energy. The idea is that the more Dark Energy there is, the more space it creates, and the more space there is, the more Dark Energy there is to create more new space. The strength of Dark Energy may increase as more of it becomes available and the effects of it can include an expansion of the universe, not only increasing the space but at a steady increasing rate.

It is entirely possible that somewhere in the continued increase of space and Dark Energy, that something unexpected could occur. If it should increase faster than expected, then such a rapid exponential increase in the strength of Dark Energy could occur, not only at vast large scales of the universe but right down to the atomic scale as well. Here's where we start getting into the Big Rip scenario.

It could indeed occur so gradually, that no one would sense the difference. On the other hand, it's not impossible that it could occur fast enough to sense a change. If that happened, no one would sense it for long. Is there any way to know that the expansion of space could not "bump" (so to speak) and suddenly speed up faster than it already is? Keep in mind that the Big Rip scenario isn't just talking about space at large scale. It's talking about space at all scales. The idea is that everything in the universe would start to come apart. At the atomic scale, the space between the nucleus of an atom and the electron shell would increase. The fundamental forces that hold these particles together could increasingly weaken as space creates more and more distance between them, to the point that atoms would no longer be able to function as they do.

There's a reason why the Big Rip scenario could disrupt the effects of the fundamental forces. Two of the forces, Gravity and Electomagnetism have infinite ranges of distance. The Weak and Strong forces have distance ranges at the atomic and subatomic scales. If particles are pulled apart far enough, I think there'd be a disruption in that the forces would become weaker to the point of no longer being effective. It's not that the forces would necessarily cease to exist, but that they'd pretty well be useless, at least in comparison to their current state of usefulness.
The Fundamental Forces of Nature

The Four Fundamental Forces

If the event happens suddenly, you probably wouldn't know it. You be thinking normally one moment, then ZAP! thoughts suddenly end. If it happens a little more gradually, but still within a short period of time, you might well sense something isn't quite right. Your vision would begin to see things quickly blur and fade, your thoughts would become scrambled, until everything, including the atoms you're made of, all comes apart to the point that you'd no longer exist, let alone sense anything. Either way it would be a diffferent frame of reference alright. It would go from having a frame of reference to having no frame of reference for us at all. What we know as the universe would all come to an abrupt end. As for the expansion of space, who knows?

The real question is could atoms be ripped apart? The answer is yes they can. Particle accelerators are able to do that, even though it involves high speed collisions, as opposed to pulling them apart. The result is the same in that atoms are broken into smaller parts.

Now then, let me say that that's just about the Big Rip scenario. I don't think that's how the universe will end, but then I'd still have to say that I really don't know. I think the end of the universe is probably largely related to exactly what the fundamental underlying nature of universe is, or what, if any, other factors may come into play in the distant future. It could end up in any of the numerous scenarios that have been proposed, or it could end up in a way we haven't yet imagined.
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