Far Future Will See No Evidence of Universe's Origin 340
Dr. Eggman writes "According to an article on Ars Technica and its accompanying General Relativity and Gravitation journal article 'The Return of a Static Universe and the End of Cosmology', in the far future of the universe all evidence of the origin of the universe will be gone. Intelligences alive 100-billion-years from now will observe a universe that appears much the way our early 1900s view of the universe was: Static, had always been there, and consisted of little more than our own galaxy and a islands of matter. 'The cosmic microwave background, which has provided our most detailed understanding of the Big Bang, will also be gone. Its wavelength will have been shifted to a full meter, and its intensity will drop by 12 orders of magnitude. Even before then, however, the frequency will reach that of the interstellar plasma and be buried in the noise--the stuff of the universe itself will mask the evidence of its origin. Other evidence for the Big Bang comes from the amount of deuterium and helium isotopes in the universe.'"
Re:But even worse (Score:1, Interesting)
Well, maybe not with current methods, but... (Score:2, Interesting)
Re:Perhaps (Score:3, Interesting)
The way I think of it is like taking a pot of boiling water and adding vegetable oil. Let turn off the fire and all those tiny bubbles of oil will start to come together. So if the universe works like that, it might be possible it wont come back together as a single singularity, but if there is enough distance that the gravitational forces don't attract the larger groups, it's possible we could end up with many pin-point size singularities and perhaps multiple big bangs.
Again I'm not a physicist, so take it with a grain of salt and add noodles :)
A brief glimpse (Score:2, Interesting)
Honestly I never understood what gave scientists the idea that they would ever have enough of a clue to know what was going on with the universe. I'm not saying it's wrong to do. Perhaps some awesome realization will come from it. I just really hope that there aren't any scientists that truly believe beyond a shadow of a doubt that this is exactly what is happening out there.
Re:But even worse (Score:3, Interesting)
I can see it now.. the philosophical debates about who these ancient creatures might have been... about how they were doomed from the get-go by their flawed and quaint interpretations of the cosmos.
*sigh*
I am only middle aged, but I miss the future already.
Regards.
Re:Well, maybe not with current methods, but... (Score:3, Interesting)
This is because, according to our best measurements, the universe it not only expanding, but the rate of expansion is increasing with time. Thus the universe's expansion is accelerating (this is the indirect evidence for "Dark Energy [wikipedia.org]").
This is "the worst possible scenario" because it can easily be shown (in a mathematically rigorous way) that as expansion occurs, the universe will become isolated islands of matter, which are flying away from each other so fast that they cannot hope to communicate with one another. This means that ultimately no information from one region of the universe can ever reach another region, which makes it impossible to reconstruct what happened in the distant past. Worse still, it can be shown that this leads to "Heat Death [wikipedia.org]", where the universe becomes very very cold (because, for example, objects radiate energy that is lost into space and never comes back, nor is replaced by any influx of energy). The end result is that there is not enough energy density to sustain life or any organized constructs. So the end state is one of extremely high entropy, with no usable information content.
This is not just a matter of not having good enough technology. The problem is that the universe will expand and local regions will irrevocably lose the ability to probe the past. Information will be inaccessible. No matter how good your technology is, the evidence will simply be locally nonexistent (because information can't travel faster than the speed of light).
Now, having said all that, it's entirely possible that new measurements will point to something previously unknown (e.g. perhaps the explanation for dark energy changes the conclusions entirely). However if current models are mostly correct, then a progression towards locally isolated regions of space, who have no access to cosmological history, is inevitable.
What Do We *Already* See No Evidence Of? (Score:4, Interesting)
Just as an example, current thinking is that we're the first technically advanced society on earth, because we see no archaeological traces of previous societies. But, what if the previous society (or societies) had advanced technology that (a) was used to scrub the earth of their low-tech origins, and (b) left no traces when the society vanished, much as ice sculptures leave no traces when they melt?
Is there any real evidence against this sort of thing? (Occam's Razor, I know. But that's an incredibly pitiful rebuttal...)
Re:Perhaps (Score:5, Interesting)
That theory has always appealed to me as it solves once of the major questions of the universe. What led up to the big bang? The idea that the universe expands and collapse suggests that before the big bang there was another universe.
To me, the idea that there needs to be a start-point for the universe seems a little too human. We have the start of our lives, the start of the day and ultimately it all ends for each of us. But the life of an inanimate object isn't quite like that. Why can't the universe have always existed? What is time anyway, other than an abstraction of counting how often something vibrates? Isn't the idea that "it's always been there" far easier to grasp than "once there was nothing, now there is everything"?
Re:What Do We *Already* See No Evidence Of? (Score:3, Interesting)
That a civilization which has an abundance of oil, coal and natural gas would use it, doesn't imply that it is necessary. Water wheels and wind mills have been in use for a long time, and could be used to generate electricty once someone invented the generator. The steam engine only relies on a boiler than can be powered by wood. They could skip right past fossil fuels and discover biodiesel, fuel cells, solar cells and other modern forms of energy.
The biggest question to ask would be why it would vanish. Yes, civilization come and go but very rarely have we abandoned anything of consequence unless the whole city was founded on a natural resource that ran out or something like that. If a second crivilization was to araise, I think the biggest clue would be the nuclear waste, toxins and pollutants, destroyed ecosystem and traces of an infiniately large disaster which could possibly cause our abandoment or extinction.
You'll be dead anyway. Here's why (Score:5, Interesting)
The universe itself is 13.7 billion of years old. Our Sun is only about 5 billion years old.
In this interval, the universe already burned a heck of a lot of Hydrogen to Helium, and even a lot of Helium to Carbon and so on until iron. You can't really have a star powered by fusing anything heavier, because fusing heavier stuff actually takes energy.
(Anything higher than that is formed in a supernova blast. Basically some of the immense energy of the supernova is used to fuse some of the ejected elements into even higher density stuff.)
Hydrogen is really the low hanging fruit of star fuel. It's for stars what the coal mines were for the industrial revolution. It's damn easy to start fusing hydrogen. (Easier if you have some heavier elements as catalysts to start the reaction, but the hydrogen will be the fuel anyway.) It's damn hard to start fusing anything else.
Even helium is tricky. It requires some _immense_ pressures and temperatures, and a state that's already degenerate matter. It even starts to happen somewhere between 100 and 200 million Kelvin. It's also a bloody unstable process. The released power is proportional IIRC to the temperature raised to the _30th_ power, so it's easy for it to run away: more power released rises the temperature some more, which rises the power some more (and rather abruptly at that), which rises temperature, etc. A star the size of our sun would just blow itself up almost instantly if it was made of Helium and actually ignited Helium fusion.
Where I'm getting is that the universe has a finite budget of hydrogen and keeps using it fast. (Well, "fast" by cosmic scales.) And then some of it gets buried in black holes and the like too. So planning to have main sequence stars in 100 billion years, is sorta like planning to still be using the oil in the middle east by then: chances are it will have run horribly thin, long time before that.
In 100 billion years, probably the best you could get is a brown dwarf, a.k.a., a star that doesn't actually fuse anything, but it heated up when collapsing into a star, and will need a horribly long time to cool down. And hopefully a planet that's close enough to it, to be just warm enough.
They'll be few and far in between though, so no telling if one will be close enough to move to it.
Also, lemme say: the only chance of life there will be that someone moves to it. If you look at long time Earth history, the Sun started a lot cooler when the Earth atmosphere was made of methane, so the massive greenhouse effect just helped keep temperature in the right band for life to appear. Then as the Sun heated up, life switched atmosphere to oxygen. We've been walking a tightrope on the border between turning into Venus (if life appeared just a little later) or turning into a deep-frozen snowball that kills everything (if photosynthesis started just a little earlier.) And we actually had a damn close shave with complete extinction, the planet-sized snowball kind.
A brown dwarf just doesn't follow that pattern. It doesn't gradually warm up, it actually starts (very very slowly) cooling down as soon as it formed. But you can pretty much approximate it as constant temperature, for the purpose of this discussion. And therein lies the problem: if it's cool enough for a methane-atmosphere planet to evolve life, that will turn into a permanent deep-frozen wasteland as soon as it evolves photosynthesis. And if it would be warm enough for an oxygen-atmosphere planet, then it's way too hot early when that planet is still methane-based. That planet will turn into Venus before it has half a chance to evolve life.
So pretty much in 100 billion years we're looking at a dead or dying universe anyway. Worrying that they'll have witch hunts is kinda silly, when, you know, there won't be anyone alive there.
Re:But even worse (Score:2, Interesting)
Look at it this way: What if intelligences similar to ourselves were alive five billion years ago? Would they have any easier or more difficult understanding their universe as we do ours? How do we know that there weren't signals and information sources available then that have petered out today?
What it all boils down to is the sensory nature of the intelligence. Our understanding of the universe is framed in how we understand our environment. Astrophysics is merely an application of our own interpretation of things which we have only limited tools to understand. If we could personally sense neutrinos or gravity waves, for example, wouldn't our understanding of the universe be much different? It's conceivable that, if life existed in a sufficiently early period of the universe, sensory details such as these could be vital for life, while things like visible-spectrum EM pictures would be useless.
Who's to say that, 100 billion years from now, life will exist whose sensory perception takes advantage of physics that we can't? Astrophysics or quantum physics, there are things we don't understand. Perhaps the underlying causes would be more clear to life in 100 billion years than today.
Further Reading: End of the Universe (Score:3, Interesting)
Topical? Yes!
Tipping encouraged. I'll be here all week.
Re:But even worse (Score:5, Interesting)
Re:No it doesn't. (Score:2, Interesting)
The difficulty lies in transmitting it at a high enough power to still have a workable signal elsewhere in the galaxy. To this end, one could build a Dyson sphere around a sun, then block or transmit the star's light according to your signal.
Yeah, building a Dyson sphere is hard...but it has so many uses.
Not that there's necessarily anything wrong with your point of view...
Makes me wonder (Score:2, Interesting)
Oh no, I agree (Score:3, Interesting)
I just wouldn't call that "fast", even by (currently) cosmic scales. For example, I'm 37. If you told me I could get to some destination in 74 years (for example), I wouldn't call that "fast".
Now, here's a real calculation, albeit one that's still based on completely unfounded assumptions: if the decay is exponential, then 100 billion years from now (when the universe is apprxomately 114 billion years old), there will be approximately 0.75^(114/14) or 9.6% of the hydrogen left.
On the other hand, if the decay is linear, we'll have -104% hydrogen left, so we'll have to fuse anti-hydrogen! (Yes, that's just a joke.)
Re:The authors make some questionable assumptions (Score:3, Interesting)
But generally it does seem to me we have, at least in gross physiology, pretty much just what we need and not much more, so your theory seems reasonable.
Forgot that little detail (Score:3, Interesting)
Re:You'll be dead anyway. Here's why (Score:3, Interesting)
All of this is moot if there the latest ideas involving the "Big Rip" turn out to be correct.
In this scenario, Dark Energy continues to cause accelerating inflation of the universe until that inflation begins to effect objects of smaller and smaller scale. At first the galaxies will all go away, too far away to see. Later, nearer the end stars will be flung beyong our view. Very near the end, the sun will suddenly shrink out of existance and the space between the earth and the sun grows infinitely. At the very end the moon will fly away, layers of earth will peel away and blow off into space, ultimately our bodies would explode into their consituent atoms, and even those would be ripped apart into there constituents as space-time itself unraveled.
Personally I'm looking forward to femtotechnology, and making a warm and comfy home in the nice big blackhole, after mastering technologies based on manipulating gravity... That or finding a friendlier universe.