As someone who doesn’t know much about this, I'm curious:
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?
AnonC · 3h ago
I’m not an expert on this, but I read this by Lawrence M Krauss (theoretical physicist and cosmologist):
“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.
diego898 · 3h ago
Very strongly suggest you check out Isaac Asimov’s “The Last Question”
If we survive far into the future, we will learn a lot more about the structure and evolution of the Universe. It might be that the questions that our scientists can ask now will turn out to be trivial or meaningless to our descendants. Perhaps the Universe is far stranger than we can imagine.
Why, so we can extend the 10^78 years? I'm not sure you truly understand how large 10^78 years is, or even 10^10 years.
suddenlybananas · 3h ago
While it seems doubtful that people will last that long, in 10^78 years, one would think those people alive at the time would want the universe to continue.
rswail · 3h ago
Humanity has existed for 3x10^6 years (give or take), which is 1 x 10^-72 of that time period.
We don't need to worry, it is highly unlikely that humanity as we recognize it will exist.
mykowebhn · 2h ago
Agreed. It is so highly unlikely that the probability is effectively zero.
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.
bbarnett · 3h ago
Imagine if we solve it. Then hope to preserve the answer long enough, that people will care.
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?!
krapp · 3h ago
The Second Law of Thermodynamics is an immutable characteristic of our universe. Entropy in a closed system (like the universe) is irreversible.
exe34 · 3h ago
It was set to zero once, so somebody somewhere/somewhen figured it out before.
WhatsName · 2h ago
Or rather we are a fork/thread somewhere is spacetime.
blueflow · 4h ago
It is written
The researchers calculated that the process of Hawking radiation theoretically also applies to other objects with a gravitational field
but: doesn't this only apply if these objects if they have some sort of decay process going on? There are nuclides that have never been observed decaying. I would expect a white dwarf to burn out, go through radioactive decay (unstable nuclides -> stable ones) and end up as inert rock (stable nuclides) at background temperature.
jfengel · 3h ago
Hawking radiation doesn't require decay. Pairs of particles appear spontaneously. One falls into the gravitational field, losing energy.
The net energy loss comes from the gravitational field of the object, and its mass decreases. We don't have details on just what that means at a Standard Model level, but the net loss of energy means something is going to disappear even without any kind of previously understood decay.
dist-epoch · 3h ago
> Pairs of particles appear spontaneously. One falls into the gravitational field, losing energy.
That's not really true. Even Hawking admitted that's it's a simplification he did for his popular science book of what really is going on.
No, all objects with non-zero temperature radiate heat. Stars, white dwarfs, black holes, even the universe itself.
blueflow · 3h ago
I said
inert rock at background temperature
so radiated and absorbed heat should already be accounted for, right?
dist-epoch · 4h ago
Regular "stable nuclides" stuff which falls into a black hole gets spit out as Hawking radiation, so no, this is a gravitational process, radioactive decay is a standard model one.
ourmandave · 4h ago
Oh great, right after I sell my soul for immortality, then they announce this.
Thanks a lot guys.
nindalf · 3h ago
I wonder, is immortality a boon or a curse? So many depictions of immortality show the person suffering. At least there's an upper bound on the suffering though, only 10^78 years.
bulatb · 5m ago
People can't admit the grapes they'll never have are as delicious as they look. They have to be sour.
lblume · 3h ago
Assuming life to be entirely physical, of course.
anilakar · 3h ago
I had calculated I could finally afford to retire after some 10^228 years. Looks like I can safely nuke my pension savings now.
ImHereToVote · 3h ago
Don't worry. You still get to experience things when your fermionic matter is converted into bosons. Have fun.
Joker_vD · 4h ago
Huh. When I've tried to sell my soul, I was scolded that trying to sell something you don't own in the first place is bad style. Oh, and they've also changed my last name to "Asshole" in all of my papers, such pettiness :/
I think you've gotten away pretty well.
wewewedxfgdf · 4h ago
Despite it being quite a way out it's still a little sad to think the end is coming.
rswail · 3h ago
"quite a way out"... is doing a lot of work in that sentence.
fsiefken · 3h ago
Ok, well, surviving beyond 1 billion years and various extinction level events, asteroids, comets, nuclear wars, are are the first priority, we'll worry about this later.
Perhaps we can set up a secret program where AI randomly selects individuals based on merit, character to get the latest in life extension treatments, philosophical and spiritual education so they can guide us (with AI assistence) into the future and beyond the solar system.
If we survive, 'we' most probably don't exist by that time in any recognisable shape or form.
maaaaattttt · 3h ago
I suppose this time is expressed in earth years? Or what would this duration mean on a Universe scale? Also given the nature of space-time (the time and gravity relationship) wouldn't time be almost still once, let's say, year 10⁷⁷ is reached?
dvh · 4h ago
> Previous studies, which did not take this effect into account, put the lifetime of white dwarfs at 10^1100 years
That's some kind of typo no? I've only heard previous estimates for white dwarf to be trillions of years, that is significantly shorter that 10^1100
Edit: never mind, by lifetime that me proton decay, not how long they shine light
They say their findings set "a general upper limit for the lifetime of matter in the universe."
Etheryte · 4h ago
So Hawking radiation moves the estimate from the previous 10^1100 to 10^78 years. That's a pretty drastic change, but naturally, not exactly something to go and worry about. Most of us would be lucky to make it to 10^2, so there's still some way to go.
busyant · 4h ago
get your affairs in order.
coolcase · 3h ago
Another 10^3 would be good for humanity
rswail · 2h ago
People will be gathering at the Restaurant At The End Of the Universe with Douglas Adams as the host.
Ekaros · 3h ago
One more argument not to do anything about climate change. After all universe is going decay shortly...
MOARDONGZPLZ · 4h ago
I hope they’re working on finding a way to massively decrease the net entropy in the universe after this.
andreareina · 4h ago
Unfortunately there is as yet insufficient data for a meaningful answer
watt · 4h ago
Crack on with it and don't keep us in the dark!
coolcase · 3h ago
The way to do that is to do the most unlikely things
tobias_irmer · 4h ago
To me that still sounds like forever.
stavros · 3h ago
Oh no! What are we going to do about this?
andrewstuart · 3h ago
How can the universe come from an infinite point and have no Centre.
Aetheridon · 4h ago
so i wonder what comes after?
Lerc · 3h ago
If there is nothing left, does time pass? Does it pass but is meaningless? Does it no longer exist?
The same question goes for space. Is there any size to the nothingness? To go further when you have notions like inflation, can you have nothing that is increasing in volume? That would suggest a change in state an thus a sense of not yet ended.
It would be a weird thing for nothingness to change state. It seems like fertile soil for sci-fi. Imagine if space itself was kind of Turing complete and once the noise of matter ended it could start the real work, which of course would be simulating the next universe.
coolcase · 3h ago
There is a theory out there that once heat death is done distance is meaningless, therefore zero, therefore big bang again.
Lerc · 3h ago
That was kind of my intuition as well, similarly for time, if there was no distinction between long and short amounts of time, an instant would be the same as eons. If the big bang was improbable but possible it would just happen. The fact that we are here is suggestive that is possible.
mr_toad · 3h ago
> It would be a weird thing for nothingness to change state.
If there are no physical laws, there’s nothing to stop that happening.
rswail · 2h ago
That question makes no sense in terms of this discussion. The heat death of the universe means that there is no "after", just as there was no "before" the Big Bang.
The actual concept of time does not exist (at least in my humble year 12 physics understanding and having read Brief History Of Time a long time ago :) )
willis936 · 4h ago
A fun tool to think around such things are Penrose diagrams. Personally I'm a little dubious of strong claims of what will happen in the distant future since we have such incomplete models of physics today. It takes GUTs to predict the future.
Good. Maybe now they can prove Hawking radiation in something that isn't a bath tub. Or an oven.
vijaybritto · 4h ago
My shower is theory is that there are infinite universes getting created all the time and we can never know about it because we're restricted in this universe. I love having these talks with my daughter.
Y_Y · 3h ago
There's a teapot orbiting the sun between Earth and Mars too.
thom · 3h ago
Ah, just time for another bath. Pass me the sponge somebody, will you?
m1117 · 4h ago
AI is going to take over anyways
coolcase · 3h ago
It'll be 42'd like everything else
keepamovin · 4h ago
Aw fuck, I was looking forward to curing a few more deaths and bringin the Bitchun Society to yet more barbarian tribes in the outer reaches. I wonder if my whuffie will last that long? I really don't want to deadhead so hopefully there's plenty more interesting things to do in the tail end.
aspenmayer · 3h ago
> whuffie
I started to read this book, but never finished it, but the whuffie idea has legs. Stuck with me longer than many ideas from books I did finish. Need to pick it up again.
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.
https://users.ece.cmu.edu/~gamvrosi/thelastq.html
https://users.ece.cmu.edu/~gamvrosi/thelastq.html
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.
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?!
The net energy loss comes from the gravitational field of the object, and its mass decreases. We don't have details on just what that means at a Standard Model level, but the net loss of energy means something is going to disappear even without any kind of previously understood decay.
That's not really true. Even Hawking admitted that's it's a simplification he did for his popular science book of what really is going on.
https://www.youtube.com/watch?v=UxVssUb0MsA
Thanks a lot guys.
I think you've gotten away pretty well.
Perhaps we can set up a secret program where AI randomly selects individuals based on merit, character to get the latest in life extension treatments, philosophical and spiritual education so they can guide us (with AI assistence) into the future and beyond the solar system.
If we survive, 'we' most probably don't exist by that time in any recognisable shape or form.
That's some kind of typo no? I've only heard previous estimates for white dwarf to be trillions of years, that is significantly shorter that 10^1100
Edit: never mind, by lifetime that me proton decay, not how long they shine light
They say their findings set "a general upper limit for the lifetime of matter in the universe."
The same question goes for space. Is there any size to the nothingness? To go further when you have notions like inflation, can you have nothing that is increasing in volume? That would suggest a change in state an thus a sense of not yet ended.
It would be a weird thing for nothingness to change state. It seems like fertile soil for sci-fi. Imagine if space itself was kind of Turing complete and once the noise of matter ended it could start the real work, which of course would be simulating the next universe.
If there are no physical laws, there’s nothing to stop that happening.
The actual concept of time does not exist (at least in my humble year 12 physics understanding and having read Brief History Of Time a long time ago :) )
https://youtu.be/mht-1c4wc0Q
I started to read this book, but never finished it, but the whuffie idea has legs. Stuck with me longer than many ideas from books I did finish. Need to pick it up again.
https://en.wikipedia.org/wiki/Down_and_Out_in_the_Magic_King...