5 ms·

Ok so a beer talk question to the physicists: By any measure of order, there are more disordered states than ordered states, and therefore any random change is

Ok so a beer talk question to the physicists: By any measure of order, there are more disordered states than ordered states, and therefore any random change is likely to be a change to a more disordered state, leading to the inevitable heat death of the universe. But if this decent into chaos is only about probability, then given infinite time even the infinitesimal chance of spontaneous order will have it's moment. With infinite time will order spontaneously emerge from heat death? Was Epicurus right?

coddle-hark 6y ago
The changes aren’t uniformly random though. This is akin to saying that given enough time a monkey throwing darts will eventually hit the moon.
- monkeycantype 6y ago
  that's a beautiful sentence! I was so expecting Shakespeare at the end of it.
  - 867-5309 6y ago
    username checks out
sillysaurusx 6y ago
I like your reasoning. Feynman pointed out why this doesn’t work: you have to “borrow odd”, so to speak, in order to get any effect. Which means that your slight perturbation, although miraculous, ends up having little more than an infinitesimal effect over an even smaller amount of time. Feynman put it way better than me though. It was in the Messenger Lectures series if you’re curious. 6 wonderful and accessible videos; his audience was primarily laypeople, not scientists. Quite enjoyable.
- Analog24 6y ago
  Feynman's argument was about why you can't have systems that decrease entropy continuously. It doesn't disprove that there can (and will) be downward fluctuations in entropy, which is what I believe the OP was asking about. As someone else mentioned this is the idea behind a Boltzmann Brain (which is a pretty fascinating concept).
throwaway1312 6y ago
There's a theorem "Poincaré recurrence theorem" which says if a system is finite, given infinite time, it will return to a state arbitrarily close to its initial state. While the theorem itself is well proven, I can't find a physicist who can say one way or another whether this applies to our universe. https://physics.stackexchange.com/questions/200722/poincaré-recurrence-and-immortality https://physics.stackexchange.com/questions/200722/poincaré-...
- OJFord 6y ago
  The objection hasn't been made in your SE question, so I assume I am missing something, but why does 'if a system is finite' apply to the universe? The 'given infinite time' would need to be a 'faster' infinite than universal expansion? (Obviously IANAPhysicist.)
  - minitoar 6y ago
    Not sure if I'm missing your point, but an expanding universe can still be finite.
    - OJFord 6y ago
      The food on your plate is finite, but if you're served more faster (no slower) than you eat it, then you won't empty the plate even given infinite time.
      - minitoar 6y ago
        That doesn’t sound like a closed system anymore.
  - enkid 6y ago
    The visible universe is finite and the visible universe is the only thing that can affect us. I believe that would make it apply.
    - 6y ago
scythe 6y ago
>With infinite time will order spontaneously emerge from heat death? The answer may be yes or no in any particular axiomatization (model) of the physical laws, but depends strongly on the choice of model. Unlike a normal situation, when we talk about very-low-probability effects we are subject to any influence of "quantum gravity" and other "new/unknown physics" that may have a finger, however light, on the scale. In the Standard Model I think the answer is yes, but we are already aware of some deficiencies (neutrino transitions).
- monkeycantype 6y ago
  Thanks - that's a really interesting answer.
douglaswlance 6y ago
Heat death leads to absolute uniformity throughout the universe and when that happens, when no two points of the universe differ in any way, the universe becomes a single point and then a big bang occurs, according to Penrose.
- Ygg2 6y ago
  Argument was a bit more complicated. Basically when all particles are moving at speed of light, time becomes meaningless and you can consider space to be infinitely small. I.e. identical conditions to Big Bang https://youtu.be/PC2JOQ7z5L0 https://youtu.be/PC2JOQ7z5L0
- deleted 6y ago
  [deleted]
ianai 6y ago
That’s pretty similar to the argument Penrose makes - check out some of his interviews.
dogecoinbase 6y ago
This is the Boltzmann Brain paradox -- given this probability system, it's much (not going to say infinitely... but practically so) more likely that your perception of this moment is a fluctuation in chaos than that the entire universe as you perceive it currently exists. The parallels to the simulation argument/doomsday hypothesis are, I hope, apparent.
mehrdadn 6y ago
> then given infinite time even the infinitesimal chance of spontaneous order will have it's moment. Does this hold true for a 1/infinity chance event? Or (not sure if this is analogous) if you choose infinitely many real numbers ~ unif(0, 1), is it guaranteed you will hit every number in that interval at least once? I'm not even sure the question is well-defined to be honest (at least not without making assumptions about infinities that we have no way to show hold true for this universe), but if it is, is the answer yes? It's not obvious to me.
- yk 6y ago
  The first is not well defined, the second is and as long as we are talking countable infinity, it is not. (In the uncountable case you are running into problems with definitions again.) As a matter of fact, you will not hit almost all numbers. However, you will almost surely have picked a point in any fixed interval, and that is meant with order reapers over long enough timescales. For illustration, you are almost guaranteed to not win the lottery, but when you play again and again, then after something like 14 million times playing (for the German Lotto) you will win, and again after something like 28 million times playing, and so on, so you expect to often over long enough timescales, and you can start to impose additional constrains, for example winning with consecutive numbers, or the first few primes. And after a long enough timescale you start to win again with these additional constrains.
burnte 6y ago
> With infinite time will order spontaneously emerge from heat death? The theory is more that with "infinite" expansion, the universe becomes so spread out as to in spot become emptier than the vacuum energy, and a new universe spontaneously erupts in that low energy locale. In a very small nutshell.
- Balgair 6y ago
  This relates to one of my favorite wikipedia pages: The Timeline of the Far Future. The relevant part is at the end. Essentially, given enough time, quantum effects will result in an entire new universe spontaneously popping into existence. That time is ~10^(10^(10^56)).[0] But, the number of ways that all particles in the universe can be arranged is only ~10^(10^115). That number is much smaller than the time to just go 'pop, new universe'. So, the much larger number also becomes about the time it takes to just have a new universe identical to our current one just go 'pop, new universe'. The other entries in that article are just as joyously mind-bending. I really really love that page! https://en.wikipedia.org/wiki/Timeline_of_the_far_future https://en.wikipedia.org/wiki/Timeline_of_the_far_future [0] Side note: The time for a 'Boltzmann Brain' (a consciousness that just floats in the infinite void thinking away, somehow) to spontaneously appear is only ~10^(10^50). EDIT: Changed Fat to Far
  - curiousllama 6y ago
    Cmon dude. Just because it keeps expanding doesn’t mean you can call the universe fat.
    - Balgair 6y ago
      Thanks for the catch! Also, I forgot to mention that all these timelines are in years. But then I thought about it and about any human unit of time really doesn't change the numbers much at all. Heck, even measured as units of 'age-of-the-current-universe', the extra 0s just fade into the rounding errors very quickly. To be clear here, that is stating that however you measure time pretty much has no meaning at these scales.
crazydoggers 6y ago
In addition to the other great comments here, check out Brian Greene’s latest “Until the End of Time” https://www.amazon.com/dp/0593171721/ref=cm_sw_r_sms_awdb_btf_t1_alNFFb1ETF902 https://www.amazon.com/dp/0593171721/ref=cm_sw_r_sms_awdb_bt... For example a complete brain capable of imagining it’s in a universe could spontaneously occur... (Boltzmann brain) but the catch is that there needs to be enough usable energy for it to function. So even if order suddenly occurs, heat death means an eventual limit to complexity. Ultimately something needs to happen to cause a sudden reverse into very low entropy, ie another Big Bang or something of the like. We’re talking like 10^50 years here before heat death ends thought so... the universe has some time still.

coddle-hark 6y ago

The changes aren’t uniformly random though. This is akin to saying that given enough time a monkey throwing darts will eventually hit the moon.

monkeycantype 6y ago
that's a beautiful sentence! I was so expecting Shakespeare at the end of it.
- 867-5309 6y ago
  username checks out

sillysaurusx 6y ago

I like your reasoning. Feynman pointed out why this doesn’t work: you have to “borrow odd”, so to speak, in order to get any effect. Which means that your slight perturbation, although miraculous, ends up having little more than an infinitesimal effect over an even smaller amount of time. Feynman put it way better than me though. It was in the Messenger Lectures series if you’re curious. 6 wonderful and accessible videos; his audience was primarily laypeople, not scientists. Quite enjoyable.

Analog24 6y ago
Feynman's argument was about why you can't have systems that decrease entropy continuously. It doesn't disprove that there can (and will) be downward fluctuations in entropy, which is what I believe the OP was asking about. As someone else mentioned this is the idea behind a Boltzmann Brain (which is a pretty fascinating concept).

throwaway1312 6y ago

There's a theorem "Poincaré recurrence theorem" which says if a system is finite, given infinite time, it will return to a state arbitrarily close to its initial state. While the theorem itself is well proven, I can't find a physicist who can say one way or another whether this applies to our universe. https://physics.stackexchange.com/questions/200722/poincaré-recurrence-and-immortality https://physics.stackexchange.com/questions/200722/poincaré-...

OJFord 6y ago
The objection hasn't been made in your SE question, so I assume I am missing something, but why does 'if a system is finite' apply to the universe? The 'given infinite time' would need to be a 'faster' infinite than universal expansion? (Obviously IANAPhysicist.)
- minitoar 6y ago
  Not sure if I'm missing your point, but an expanding universe can still be finite.
  - OJFord 6y ago
    The food on your plate is finite, but if you're served more faster (no slower) than you eat it, then you won't empty the plate even given infinite time.
    - minitoar 6y ago
      That doesn’t sound like a closed system anymore.
- enkid 6y ago
  The visible universe is finite and the visible universe is the only thing that can affect us. I believe that would make it apply.
  - 6y ago

scythe 6y ago

>With infinite time will order spontaneously emerge from heat death? The answer may be yes or no in any particular axiomatization (model) of the physical laws, but depends strongly on the choice of model. Unlike a normal situation, when we talk about very-low-probability effects we are subject to any influence of "quantum gravity" and other "new/unknown physics" that may have a finger, however light, on the scale. In the Standard Model I think the answer is yes, but we are already aware of some deficiencies (neutrino transitions).

monkeycantype 6y ago
Thanks - that's a really interesting answer.

douglaswlance 6y ago

Heat death leads to absolute uniformity throughout the universe and when that happens, when no two points of the universe differ in any way, the universe becomes a single point and then a big bang occurs, according to Penrose.

Ygg2 6y ago
Argument was a bit more complicated. Basically when all particles are moving at speed of light, time becomes meaningless and you can consider space to be infinitely small. I.e. identical conditions to Big Bang https://youtu.be/PC2JOQ7z5L0 https://youtu.be/PC2JOQ7z5L0
deleted 6y ago
[deleted]

ianai 6y ago

That’s pretty similar to the argument Penrose makes - check out some of his interviews.

dogecoinbase 6y ago

This is the Boltzmann Brain paradox -- given this probability system, it's much (not going to say infinitely... but practically so) more likely that your perception of this moment is a fluctuation in chaos than that the entire universe as you perceive it currently exists. The parallels to the simulation argument/doomsday hypothesis are, I hope, apparent.

mehrdadn 6y ago

> then given infinite time even the infinitesimal chance of spontaneous order will have it's moment. Does this hold true for a 1/infinity chance event? Or (not sure if this is analogous) if you choose infinitely many real numbers ~ unif(0, 1), is it guaranteed you will hit every number in that interval at least once? I'm not even sure the question is well-defined to be honest (at least not without making assumptions about infinities that we have no way to show hold true for this universe), but if it is, is the answer yes? It's not obvious to me.

yk 6y ago
The first is not well defined, the second is and as long as we are talking countable infinity, it is not. (In the uncountable case you are running into problems with definitions again.) As a matter of fact, you will not hit almost all numbers. However, you will almost surely have picked a point in any fixed interval, and that is meant with order reapers over long enough timescales. For illustration, you are almost guaranteed to not win the lottery, but when you play again and again, then after something like 14 million times playing (for the German Lotto) you will win, and again after something like 28 million times playing, and so on, so you expect to often over long enough timescales, and you can start to impose additional constrains, for example winning with consecutive numbers, or the first few primes. And after a long enough timescale you start to win again with these additional constrains.

burnte 6y ago

> With infinite time will order spontaneously emerge from heat death? The theory is more that with "infinite" expansion, the universe becomes so spread out as to in spot become emptier than the vacuum energy, and a new universe spontaneously erupts in that low energy locale. In a very small nutshell.

Balgair 6y ago
This relates to one of my favorite wikipedia pages: The Timeline of the Far Future. The relevant part is at the end. Essentially, given enough time, quantum effects will result in an entire new universe spontaneously popping into existence. That time is ~10^(10^(10^56)).[0] But, the number of ways that all particles in the universe can be arranged is only ~10^(10^115). That number is much smaller than the time to just go 'pop, new universe'. So, the much larger number also becomes about the time it takes to just have a new universe identical to our current one just go 'pop, new universe'. The other entries in that article are just as joyously mind-bending. I really really love that page! https://en.wikipedia.org/wiki/Timeline_of_the_far_future https://en.wikipedia.org/wiki/Timeline_of_the_far_future [0] Side note: The time for a 'Boltzmann Brain' (a consciousness that just floats in the infinite void thinking away, somehow) to spontaneously appear is only ~10^(10^50). EDIT: Changed Fat to Far
- curiousllama 6y ago
  Cmon dude. Just because it keeps expanding doesn’t mean you can call the universe fat.
  - Balgair 6y ago
    Thanks for the catch! Also, I forgot to mention that all these timelines are in years. But then I thought about it and about any human unit of time really doesn't change the numbers much at all. Heck, even measured as units of 'age-of-the-current-universe', the extra 0s just fade into the rounding errors very quickly. To be clear here, that is stating that however you measure time pretty much has no meaning at these scales.

crazydoggers 6y ago

In addition to the other great comments here, check out Brian Greene’s latest “Until the End of Time” https://www.amazon.com/dp/0593171721/ref=cm_sw_r_sms_awdb_btf_t1_alNFFb1ETF902 https://www.amazon.com/dp/0593171721/ref=cm_sw_r_sms_awdb_bt... For example a complete brain capable of imagining it’s in a universe could spontaneously occur... (Boltzmann brain) but the catch is that there needs to be enough usable energy for it to function. So even if order suddenly occurs, heat death means an eventual limit to complexity. Ultimately something needs to happen to cause a sudden reverse into very low entropy, ie another Big Bang or something of the like. We’re talking like 10^50 years here before heat death ends thought so... the universe has some time still.