Will the Universe exist forever?

[Mr Rayon]

Will it ever cease to exist?

 

And what about humans, will humans always exist forever? What's the general consensus?

[ajb]

One suggestion is that the universe will exist forever, but at the state of maximal entropy. This heat death scenario will not be able to support life. This will not happen for at least another [math]10^{100}[/math] years or so.

[Zarnaxus]

What if our membrane collides into another?

 

 

[mathematic]

The earliest date for an astronomical end of life on earth is about one billion years when the sun will be so hot that water on the earth would boil off.

[lemur]

The earliest date for an astronomical end of life on earth is about one billion years when the sun will be so hot that water on the earth would boil off.

Unless a dyson sphere has been built by that time that harnesses so much of the sun's power that Earth's exposure to solar energy is sufficiently mitigated.

[ajb]

What if our membrane collides into another?

 

If we do live on a membrane that is a possibility and would be disastrous. You may be interested in [1].

 

References

 

[1] Warren B. Perkins. Colliding Bubble Worlds, Phys.Lett. B504 (2001) 28-32 (also available as arXiv:gr-qc/0010053v1 )

[DrRocket]

Will it ever cease to exist?

 

And what about humans, will humans always exist forever? What's the general consensus?

 

It will last until the end of time.

 

We won't.

[Zarnaxus]

It there a possibility that all the protons in the universe will eventually decay?

[rktpro]

What is big crunch then? I read somewhere that one day, or at a point of time, gravity will overcome mass.

[imatfaal]

Gravity overcome mass? Not sure what that means.

 

On the big crunch issue - I think the balance of opinion is that galaxies have escape velocity and will thus continue to spread out, rather than slow and begin to contract. It is all to do with the average mass/energy density, if the density is high enough then the speed with which galaxies are moving apart will not be enough and sooner or later they will fall back together, if the density is below that critical figure then the galaxies have enough speed to escape forever.

 

This means we need to know the relative velocity with great precision and the amount of mass/energy in the universe similarly. Around 15 years the sums lead scientists to the conclusion that the expansion was not only fast enough overcome gravitational attraction but was actually accelerating - this is the dark energy question. the fact that we really don't know the rationale of dark energy means that nothing can be really ruled out until we do understand that.

[rktpro]

Gravity overcome mass? Not sure what that means.

 

 

I think it might mean that gravity will increase and would result in collapse. But isn't gravity a property of mass? How can it increase?

[imatfaal]

I think it might mean that gravity will increase and would result in collapse. But isn't gravity a property of mass? How can it increase?

 

The original question that arose, once we understood that the universe was not steady-state, was whether there was enough mass to cause the universe to reverse its expansion.

 

This was a book-keeping problem - we just didn't know exactly enough how much mass was in the volume. A critical mass-energy density was calculated; ie if a galaxy at x distance is moving at y speed then if the mass-energy density is greater than z the galaxy will not have escape velocity and if it is less than z the galaxy will have escape velocity. The theories did not concern changing mass or changing gravity - just how much there actually was.

 

Dark energy has complicated this picture

[hawksmere]

In direct answer to the question, the Universe will expire. Yes (subject multiverses), ours will. The exact date is unknown as the asymmetry of time tells us the amount of usable energy will become negligible. The anthropic principle however states that 'our' (observers) are to be considered throughout the duration and completely relevant to the existence. Douglas Adams "the universe may appear to fit them perfectly, while in fact, they simply fit the universe perfectly". Black hole singularity is nothing but a theory but supported heavily, especially when the Hubble is following this 'arrow of time' and monitoring the expansion. The big freeze, chill of the big Crunch will, in my opinion, be long after humans left - Naturally as the Sun will die, extinguishing life [here] entirely.

 

In the Gurbani it is simply stated. 'All that is born, in time, will have a death, in time'. The universe had its birth so must have its death. May be worth considering the relationship of this universe and others - should they exist of course

 

 

Edited May 31, 2011 by hawksmere

[ajb]

In the Gurbani it is simply stated. 'All that is born, in time, will have a death, in time'. The universe had its birth so must have its death. May be worth considering the relationship of this universe and others - should they exist of course

 

Because a guru's have stated that 'All that is born, in time, will have a death, in time' in what ever context they did, does not mean that we can apply this modern cosmology. Of course, there are scenarios in cosmology that would involve "the death of the Universe" but this in no way vindicates what the guru's said nor its application in cosmology.

[DrRocket]

Because a guru's have stated that 'All that is born, in time, will have a death, in time' in what ever context they did, does not mean that we can apply this modern cosmology. Of course, there are scenarios in cosmology that would involve "the death of the Universe" but this in no way vindicates what the guru's said nor its application in cosmology.

 

 

Right.

 

Unfortunately some well-known physicists have recently published books for the general public that have about as much foundation as the gurus mutterings. See Hawking's The Grand Design or Steinhardt and Turok's Endless Universe: Beyond the Big Bang. It seems to me that before one uses M theory to solve the mysteries of the universe one ought to settle the major open question of M theory -- namely "What is M theory" ?

 

Mysticism is mysticism.

[ajb]

[/i]It seems to me that before one uses M theory to solve the mysteries of the universe one ought to settle the major open question of M theory -- namely "What is M theory" ?

 

The only real plausible title is Mbrane theory as M-theory consists two generic kind of branes, M2 and M5. Matrix theory was also once proposed as it was thought that a quantum mechanical theory based on matrices could describe the degrees of freedom of M-theory in some limit. I have not heard much about Matrix theory recently.

[Newbies_Kid]

Simply i say no