If humanity survived far into the future, could we plausibly develop ways to slow or even halt the decay of the universe? Or is this an immutable characteristic of our universe, meaning humanity will inevitably fizzle out along with the universe?
“In 5 billion years, the expansion of the universe will have progressed to the point where all other galaxies will have receded beyond detection. Indeed, they will be receding faster than the speed of light, so detection will be impossible. Future civilizations will discover science and all its laws, and never know about other galaxies or the cosmic background radiation. They will inevitably come to the wrong conclusion about the universe......We live in a special time, the only time, where we can observationally verify that we live in a special time.”
A billion is just 10 to the power of nine, and that number of years in time is itself a long, long time that’s difficult to imagine. Looking at 10 to the power of 78 is…it wouldn’t matter much for us if it were to the power of 60 either. (I think!) I seriously doubt humans (as we know of now) can meaningfully affect the expansion or decay of the universe.
Incidentally, the obvious counter to "our time is special, we have access to everything" is presumably what future civilisations think as well; the implication being perhaps we have lost something over the aeons that would shed light on our current mysteries.
I haven't read the book but it's an unconvincing extract, though I acknowledge a larger context may justify it.
>And what are presently the closest galaxy groups outside of the Local Group — objects like the M81 group — will be the last to become unreachable: something that won't occur until more than 110 billion years from now, when the Universe is nearly ten times its present age.
What's fascinating to me is to consider the frontier of galaxies theoretically reachable within a given window, and the potential race to colonize them before they race away.
That's... awe inspiring.
The Hubble constant is currently approximately one doubling per 14 billion years [1]. So 5 billion years isn't enough to double the recession speeds. AFAIK there's plenty of galaxies receding at less than half the speed of light. Wikipedia estimates 150 billion years (6000x expansion) for all but the local group to be beyond the horizon [2]. So your quote seems to be off by two orders of magnitude.
[1]: https://astronomy.stackexchange.com/questions/49248/interpre...
[2]: https://en.wikipedia.org/wiki/Timeline_of_the_far_future
Yeah, seems off. According to Wikipedia it's 2 trillion years[1] until galaxies outside the Local Supercluster become undetectable.
[1]: https://en.wikipedia.org/wiki/Future_of_an_expanding_univers...
It is a big project, but don’t worry, you’ve got quite a while to work it all out. I would start working on it in earnest in about a million years. If you wait a couple billion, more of the stuff in the universe might have decayed, and the end result might be less interesting, I guess.
Please tell whatever else is around about the rest of us!
When things are predictable they can be simulated fast : A spinning ball in the void can be simulated for 10^78 years in O(1).
When things are fuzzy, they can be simulated fast : A star made of huge number of atoms is not so different than another star made of a huge number of atoms. When processes are too complex they tend to all follow the law of large numbers which makes the computations memoizable.
What you want is a way to prevent the universe from taking shortcuts in its computations. Luckily its quite easy. You have to make details important. That's where chaos theory comes to the rescue. Small perturbations can have big impacts. Bifurcations like tossing a coin in the air create pockets of complexity. But throw too many coins in the air and its just random and boring. Life exists on this edge where enough structure is preserved to allow enough richness to exist.
One way humans have found of increasing precision is the lathe, which lead to building computers. Build a big enough fast enough computer and you will run-out of flops faster than reaching the 10^78 endgame.
But you have to be smart, because computation being universal it means that if you are just building a big computer what matters will be what runs on it. And your universe can be reduced to a recursive endgame state of "universe becoming a computer running universe simulation of a specific type", which doesn't need to computed more than once and already was, or isn't interesting enough to deserve being computed.
That's why we live on the exciting edge before the Armageddon, boring universes having already been simulated. The upside being universe hasn't yet decided which endgame we may reach, because the phytoplankton aliens of k2-18b have not yet turned on their supercomputer.
Instead, its response—"INSUFFICIENT DATA FOR MEANINGFUL ANSWER"—is a model of intellectual honesty.
The first problem is data integrity and storage. Will the atoms the answer is on, still be around?
The next is, what kind of search engine will we have, with 10^78 years of internet history?!
All the things like stars will be long gone and dead before that time leaving us with long lived black holes and radiation. So everything would be based on virtual world can computation by that point. Do you just cool everything to near absolute zero and run it as slow as possible to you can last as long as possible?
The History of the Universe channel has an episode around this, but I'll have to figure out which one it was.
The World at the End of Time by Frederick Pohl.
https://en.wikipedia.org/wiki/Iron_star#Compact_iron_star_fo...
...although I'm not sure I've ever seen the expected temperature of iron stars. 1 milliKelvin?
We don't need to worry, it is highly unlikely that humanity as we recognize it will exist.
Let's give everyone the benefit of the doubt and assume that humanity can exist a thousand times longer than your estimate, say 3x10^9 years. That's about as long as we think life has existed on earth, which is a VERY LONG TIME. That said, it's still 1 x 10^-69 of that time period. I think you can see where we're going with this.
Why would you hope this? This hope seems to me a vestige of the desire of some humans for immortality. And why would it matter to folks whether some sort of intelligence existed this incomprehensibly far into the future?
We are barely able to handle technological progress that would seem like stone age or even worse to a potential species that may exist at that time (ie those that may have such technology to stop the death of the very universe they are living)
They might just be indistinguishable from a god if there is one. And if they have enough power to perhaps prevent the death of the universe, they might have enough technology to just recreate another one. Or open a wormhole and transport to a new one or travel the multiverse or something.
Basically I feel if such kind of technology can be created to bend the universe to your will, it would be misused so badly, it might be catastrophic for the existence of such a species.