[colarris (OP)]

 Its common knowledge that the sun is going to die at some point but I was a little startled to read recently that the entire universe will eventually die, all its energy used and just becoming  cold life space. Have the theorists got any crazy ideas on how we could escape this fate and continue life as we know it?

[CliffordK]

The predictions are that the sun will die in 4 to 5 billion years. 

Or, one can consider Earth as now being middle-aged, with the entire time from the formation of the planet, abiogenesis, and the evolution from prokaryotes to eukaryotes, to humanity left in Earth's future.

There are questions about climate instability in the distant future, but I believe that up until "the end", we will be able to engineer climate modification systems to preserve life on Earth. 

As the sun moves to a Red Giant phase, there may be a mass migration to outer planets and moons, or assuming they are colonized in the near future, perhaps they will just replace Earth life.

The predictions are that after the sun enters its Red Giant phase, it will shrink to a white dwarf.  It will continue to emit light and heat for billions of years, but at a much lower level.  Perhaps that will be a stimulus to build something resembling a Dyson's Sphere.

While our sun has a life expectancy of about 10 billion years.  Larger stars have a much shorter lifespan.  Smaller stars can endure much longer, perhaps on the order of 100 billion years to a trillion years.

If the universe is powered by Hydrogen and Helium, eventually it should run out.  That is unless there is some ability for the light elements to regenerate.  For example, black holes may convert heavy elements into light elements.  At which point, the potential duration of the Universe becomes much longer.

Currently, as a species, we have troubles planning into the next few decades, or centuries.  If humanity endures for the next billion, or trillion years, it will certainly change and evolve.

Or, perhaps we'll simply replace ourselves with computers and our "creations".

[Soul Surfer]

No. Both of the death of our sun and our universe are things that are clearly predicted totally logical and inevitable.  We live in an evolutionary universe and absolutely nothing is totally permanent although some things like black holes can last a very long time.

To expect more than this is totally unreasonable and I am perfectly happy and see nothing wrong with this.  "all things must pass"

Mankind is an important but non essential feature of the ecosystems of this planet.  In fact it is currently doing its best to destroy them, firstly with excessive population and then with excessive greed.  Because of this it will probably die out or have to change very radically long before either of the cut off dates that you suggest (which are many billions of years in the future) get anywhere near happening. To last more than a few thousand years from today will require a vastly different attitude to economics and a very significant period of sustained austerity of the sort that makes the current global recession look like a minor blip.

[Geezer]

CARPE DIEM

[lightspeed301]

Cliff and Soul

Soul - You wrote: "Both of the death of our sun and our universe are things that are clearly predicted totally logical and inevitable."

I agree our sun will die and become a white dwarf. And I agree with Soul that humans can survive even the end of the sun. However, there is absolutely nothing that predicts the universe will end.  I will give you two reasons.

First, current theory has space expanding at ever increasing velocities to the point of near absolute zero. I will even stipulate quarks will evaporate into photons. I am even willing to entertain the idea photons themselves could evaporate. But the universe does not end. It is simply never ending in this scenario.

On the other hand, we do not know that acceleration in the expansion of space is not in itself a scalar force that will suddenly stop. Just like inflation suddenly stopped.

[CliffordK]

One should ask if there is a finite amount of energy in the universe?
And, will it ever be used up?

Is it a closed system, or an open system?

If all the energy in the universe is derived from fusion, mostly the fusion of hydrogen and helium, but essentially the fusion of anything up to Iron.

Then eventually, all the fusible material will be used up, at which point the Universe will become a very cold place.

That is, unless hydrogen is being reformed, and able to start the whole process over again.  In which case, perhaps energy is still being lost, but the time period would be much much longer.

[Geezer]

In this particular Universe, energy is never destroyed. It just gets redistributed.

If it ever gets to a point where there is no energy gradient anywhere within it, it's effectively kaput because it has reached its lowest possible state.

At that point it's game over. Entropy wins.

[CliffordK]

Matter is the minority of the universe.
Much of the energy at the surface of stars is released as high energy photons, many of which seem to travel on forever without encountering and being absorbed by solid matter. 
Whether or not these wayward photons are truly lost is a matter of philosophy. 

[colarris (OP)]

Many thanks, very interesting stuff. I'm not going to pretend I understand most of this but there has been talk of alternate universes, maybe our only hope???

[syhprum]

CliffordK

"Matter is the minority of the universe"

I understand that the Sun emits photons with a mass equivelent of 80,000 tons per second, over a 5 billion year period this would amount 1.26*10^22 tons a pretty trivial amount compared to the 10^27 tons of the suns mass hence how doe's the total mass of the universe become photons.

[CliffordK]

I didn't say that the matter in the universe became photons.
The Energy of fusion becomes Photons.

Most of the Universe is empty space.  I suppose you could argue that it isn't entirely empty, but it isn't absorbing the photon energy from the stars.  If there is an "edge" to the part of the universe containing matter, then at some point, many of the photons get beyond the area where they encounter matter and impart their energy to the matter.

What happens to the wayward photons that get beyond the matter of the Universe (assuming an edge), would be pure speculation.

[Bill S]

No one mentioned the "omega point" theory with its apparently infinite capacity, contained within a finite time.  Is that because no one believes it possible now?

[Gordian Knot]

Does anyone here consider it even a remotely possible scenario that humankind will survive another four billion years? Considering our track record, I think we will be extinct billions of years before the planet expires!

[Phractality]

Theories are based on models which cannot be tested beyond the limits of human existence. Extrapolating those theories to the edge of the visible universe and to the beginning and end of time is not science; it is philosophy and religion.

[CliffordK]

Does anyone here consider it even a remotely possible scenario that humankind will survive another four billion years? Considering our track record, I think we will be extinct billions of years before the planet expires!

Yes...

Now, obviously we will evolve, perhaps no longer even recognizable in a billion years. 

Can we evolve past wars?  I don't know.
Will we face challenges?  Most certainly.
Could other species evolve on Earth to challenge us?  Perhaps.  Or, even ultra-competitive human progeny.  How will we react?  I really don't know.

What about computers?
Computers have a possibility of completely replacing menial labor in the not-so-distant future, for better or for worse.  But, some kind of self aware sentience of computers, is also inevitable, and may present humanity with one of our greatest challenges.

Anyway, short of a "Terminator-type" computer revolution, I don't foresee humanity being completely wiped out.  We are too adaptable.  If we could only choose to avoid an all-out global nuclear war.  Who ever thought of the idea of mutual assured destruction (along with initiating a global catastrophe)?

Spreading to other planets and moons in the solar system will also help preserve humanity, and could even re-seed Earth following a catastrophe, but as with colonies on Earth, there will be growing pains.

[neilep]

So long and thanks for all the fish !

[Gordian Knot]

Didn't even know sheep liked fish!

[Gordian Knot]

Does anyone here consider it even a remotely possible scenario that humankind will survive another four billion years? Considering our track record, I think we will be extinct billions of years before the planet expires!

Yes...

Now, obviously we will evolve, perhaps no longer even recognizable in a billion years. 

Obviously?? What facts are you using to support that statement? From my point of view, humans have not evolved in any significant way since Cromagnon times. We are still essentially the same biological creatures we were 3 million years ago. Only our toys have become a trillion times more deadly.

The human track record at evolution has been an abysmal failure up till now. What is going to alter that pattern? And more importantly, when??

[Bill S]

From my point of view, humans have not evolved in any significant way since Cromagnon times. We are still essentially the same biological creatures we were 3 million years ago. Only our toys have become a trillion times more deadly.

However accurate this assessment might be, we have to ask ourselves why that is so.

One possibility is that evolution is a slow process and we humans have reached a developmental stage in which we can bring about changes, from choice, faster than our natural evolution can keep up with these changes.  If we can avoid exterminating ourselves before some sort of balance can be restored, I think the human race has a good chance of protracted survival.  If not, who will miss us? 

[CliffordK]

Now, obviously we will evolve, perhaps no longer even recognizable in a billion years. 

Obviously?? What facts are you using to support that statement? From my point of view, humans have not evolved in any significant way since Cromagnon times. We are still essentially the same biological creatures we were 3 million years ago. Only our toys have become a trillion times more deadly.

The human track record at evolution has been an abysmal failure up till now. What is going to alter that pattern? And more importantly, when??

I would beg to differ.
Humans are significantly different from, say, Homo Erectus who lived 100,000 to about 2 million years ago, especially with respect to cranial capacity.

There also are significant differences between Homo Sapiens and more recent hominids, Homo Heidelbergensis and Neanderthals.

You could argue that there has been little evolution of Homo Sapiens in the last 200,000 years.  But, even this would be an oversimplification.    Racial distinctions may only be 20,000 years old or so, and how many wars have been fought over the color of people's skin?

In another topic, there is a debate on whether Humans are currently evolving, and how modern medicine will affect our species in the future.  No doubt, change can progress in leaps and bounds.  It is possible that we will get some new genes in the gene pool that will never get 100% species penetration, or in the future, there will be multiple branches of humanity.  This would be especially true if we get space faring population that become genetically isolated.

As far as success of the species.  We have gone from a few thousand individuals struggling to survive 100,000 years ago.  Perhaps nearly wiped out by some calamity.  To, by far the dominant species on the planet today. 

Despite now having created bombs that are powerful enough that a single bomb could have wiped out 100% of the small tribes of early homo sapiens...  we are hardly making a dent in our current population.

Despite killing over 10,000 Americans and over 100,000 Iraqis in a recent war, we have now hit new all-time global population records.

Considering the American and European populations as a whole, the chance of dying from trauma including war is essentially at an all-time low.

Medicine is now better than ever.

Consider, if 100% of all humans were inoculated with HIV/AIDS, there is enough natural immunity in the species (about 0.3%) that the species would survive.  The population would take a hit, perhaps to levels reminiscent of the early Holocene.  But, the species would still endure.