18 ms·

If we take the eventual heat death of the universe to be at about 10^100 years, the era we are in with stars and so on only lasts about 10^14 years. Which means

If we take the eventual heat death of the universe to be at about 10^100 years, the era we are in with stars and so on only lasts about 10^14 years. Which means light and stars and galaxies are actually just a tiny tiny blip at the start of the lifespan of the universe. Nearly all of the life of the universe will be dark with no stars, just black holes and dark distintegrating rocks and isolated particles. https://en.wikipedia.org/wiki/Future_of_an_expanding_universe#The_Stelliferous_Era https://en.wikipedia.org/wiki/Future_of_an_expanding_univers... Sweet dreams

bjornlouser 4y ago
"Nearly all of the life of the universe will be dark with no star" Maybe it will turn out that many of the double star systems were created by intelligent life
- ben_w 4y ago
  How are you thinking about stars in a way that double stars will help?
- SamBam 4y ago
  Isaac Asimov's The Last Question is an excellent short story that explores whether future civilizations will ever be able to reverse entropy. [1] Also, Ten Chiang's Exhalation is another short story about trying to stave off the entropy-death of the universe. [2] 1. https://astronomy.org/moravian/C00-Last%20Question.pdf https://astronomy.org/moravian/C00-Last%20Question.pdf (pdf) 2. https://www.lightspeedmagazine.com/fiction/exhalation/ https://www.lightspeedmagazine.com/fiction/exhalation/
GalenErso 4y ago
I refuse to believe that the Universe isn't cyclical, because I believe the Universe has existed forever, otherwise there is no answer to the origin of everything other than something from nothing or God.
- PUSH_AX 4y ago
  Why is one of those answers better than the other?
  - haswell 4y ago
    Believing one has a tendency to cause people to fundamentally alter how they live their lives, optimize for an afterlife at the expense of the life they actually have, and then fight wars over the belief that the afterlife is the only one that matters. As a default state of not knowing, one causes far more material harm in our current reality than the other.
    - edgyquant 4y ago
      This seems like your biased interpretation actually. Most people believe in God and most people don’t start wars.
      - bandie91 4y ago
        altough I agree with this datapoint. however the parent post's concern was not about majority, but that monotheism causes violence at all, and it causes more damage to material goods than lack of monotheism. i once disagree that monotheism, which values non-material things more than material ones, neccessarily leads to destruction of the material. orthodox Christianity for example values material and non-material, soul and body equally. secondly i disagree that this argument is valid. since if you are in the viewpoint of "all that matters is the non-material" then wasting material does not harm the world. and simirarly, supposedly saving souls at the expense of the body is incomprehensible to the materialist. so the term "harm" understood in 2 disjunct ways per the 2 frameworks. circling back to orthodoxy: it unites the "saving souls" and "saving forests" (understand well, it's not about trees, but the whole material creation clamped together in a catchphrase) attitudes in the mystery of Incarnation.
    - bandie91 4y ago
      standing on a viewpoint of ca. "the cause of everything is a spaceless, timeless, immaterial, powerful, intelligent, personal being" (ie. the pilosophers' God) does not entail the Abrahamic religions' image of God directly, nor an afterlife of humans, nor a right to self defence, nor commission of evangelization nor jihad.
Aperocky 4y ago
This is YOLO on the universe level.
ye-olde-sysrq 4y ago
"How can the net amount of entropy of the universe be massively decreased?"
- andai 4y ago
  For the uninitiated: https://users.ece.cmu.edu/~gamvrosi/thelastq.html https://users.ece.cmu.edu/~gamvrosi/thelastq.html
  - dontwearitout 4y ago
    Thank you for sharing this!
- MichaelZuo 4y ago
  What does 'net amount of entropy' mean?
  - ye-olde-sysrq 4y ago
    You can already decrease entropy locally, but net for the entire universe, entropy (as far as we can tell...) always increases monotonically. And any action you take to decrease local entropy still actually increases it in total. So "The Last Question" is also basically asking - "how can we avoid the heat death of the universe?". And phrased yet again differently: "Once all the stars burn out and all the uranium is fissioned and the coal burned and the universe is just a homogenous 5 degree kelvin soup of [I'm sure some physicist could tell me whatever fundamental particle it'll be that composes this soup] - what then? Is that just it?"
    - twawaaay 4y ago
      Once all stars die you will be able to live very long off of the heat of dead stars as they slowly cool off to background temperature. And once those stars are completely cold, you can start converting their mass into energy by dropping them into black holes, piece by piece. And once you dropped all matter you could into black holes you could live off merging black holes. And once you merged black holes you could live off of the black hole radiation until all black holes evaporate. But this would be if the Universe wasn't expanding at a growing rate. If the Universe is truly expanding at an ever accelerating pace there will come a Big Rip which will cause every fundamental particle to get further from all other particles at speeds faster than light. And then matter as we know it will cease to exist.
bena 4y ago
This sort of thing always fascinates me. This is all true and it absolutely does not matter. The thought of the universe sitting essentially idle for 10^86 years seems like it should feel wasteful. But why? Wasting what? Does our consciousness imbue the universe with any special quality? It's all so weird. Even some of our most fantastical science fiction only projects out a few millennia. Star Trek gets to the 31st century (or 3000s). Foundation is at least 12,000 years in the future. Dune takes place from about 23,000 to about 28,000. Warhammer 40k gets its name from the fact it takes place in the 40,000s. The Time Machine reaches to the 800,000s for the majority of its action. Red Dwarf is set the furthest at 3,000,000-ish. All of which fall way short of even 1 billion years. The Andromeda and Milky Way galaxies aren't scheduled to meet up for another 5 billion. We aren't even a blip.
- lanna 4y ago
  > The thought of the universe sitting essentially idle for 10^86 years 10^100 years minus 10^14 years is not 10^86 years. It is roughly 10^100 years.
- badcppdev 4y ago
  Small correction to your maths but not your sentiment. 10^100 years - 10^14 years = approx. 10^100 years In the same way that: 10^6 - 10^3 = 1,000,000 - 1000 = 999,000 which is more or less approx. 10^6 Edit: Although this is one of those relatively uncommon situations where it doesn't really matter if you're off by 100 trillion years.
  - bena 4y ago
    True enough. I honestly did not care enough to do anything but the most cursory attempt at math due to the scale involved. 10^14 years and 10^100 are effectively equal compared to even our entire species current lifespan.
    - Taywee 4y ago
      Yeah, it can be boiled down to "there will be stars for longer than you can fathom, then there won't be stars for longer than you can fathom". It's hard to really feel much about different timespans that are all "forever" relative to the entirety of human existence.
thisismyswamp 4y ago
This is meaningless, nothing about those numbers matters neither does it say anything conclusive about the nature of reality. It's just our best guess right now, and we are very early.
- Aperocky 4y ago
  I find this interesting about human nature, that is in the want to believe in something eternal. Even if current theory about Universe is proven correct, it will most likely have no effect whatsoever on current human lifetimes. But doesn't preclude us from wanting to believe that the universe is eternal and constant, that there will be flashes of life and activity 10^50 years down the line.
  - thisismyswamp 4y ago
    I find the reverse interesting - this anti-conventional desire to reduce scary questions to meaningless quantities in order to intellectually one up everyone else.
    - jacquesm 4y ago
      Or, maybe they're just right.
      - edgyquant 4y ago
        Impossible to know but seemingly illogical.
- didntreadarticl 4y ago
  True, there are other options https://en.wikipedia.org/wiki/Big_Crunch https://en.wikipedia.org/wiki/Big_Crunch https://en.wikipedia.org/wiki/Big_Rip https://en.wikipedia.org/wiki/Big_Rip https://en.wikipedia.org/wiki/False_vacuum_decay https://en.wikipedia.org/wiki/False_vacuum_decay etc
__MatrixMan__ 4y ago
If this haunts your dreams, consider "The Life of the Cosmos" By Lee Smolin, as antidote. In that book he proposes that each of those black holes has a child universe associated with it, some of which have sets of physical constants that allow for grandchildren. It's a fun read.

bjornlouser 4y ago

"Nearly all of the life of the universe will be dark with no star" Maybe it will turn out that many of the double star systems were created by intelligent life

ben_w 4y ago
How are you thinking about stars in a way that double stars will help?
SamBam 4y ago
Isaac Asimov's The Last Question is an excellent short story that explores whether future civilizations will ever be able to reverse entropy. [1] Also, Ten Chiang's Exhalation is another short story about trying to stave off the entropy-death of the universe. [2] 1. https://astronomy.org/moravian/C00-Last%20Question.pdf https://astronomy.org/moravian/C00-Last%20Question.pdf (pdf) 2. https://www.lightspeedmagazine.com/fiction/exhalation/ https://www.lightspeedmagazine.com/fiction/exhalation/

GalenErso 4y ago

I refuse to believe that the Universe isn't cyclical, because I believe the Universe has existed forever, otherwise there is no answer to the origin of everything other than something from nothing or God.

PUSH_AX 4y ago
Why is one of those answers better than the other?
- haswell 4y ago
  Believing one has a tendency to cause people to fundamentally alter how they live their lives, optimize for an afterlife at the expense of the life they actually have, and then fight wars over the belief that the afterlife is the only one that matters. As a default state of not knowing, one causes far more material harm in our current reality than the other.
  - edgyquant 4y ago
    This seems like your biased interpretation actually. Most people believe in God and most people don’t start wars.
    - bandie91 4y ago
      altough I agree with this datapoint. however the parent post's concern was not about majority, but that monotheism causes violence at all, and it causes more damage to material goods than lack of monotheism. i once disagree that monotheism, which values non-material things more than material ones, neccessarily leads to destruction of the material. orthodox Christianity for example values material and non-material, soul and body equally. secondly i disagree that this argument is valid. since if you are in the viewpoint of "all that matters is the non-material" then wasting material does not harm the world. and simirarly, supposedly saving souls at the expense of the body is incomprehensible to the materialist. so the term "harm" understood in 2 disjunct ways per the 2 frameworks. circling back to orthodoxy: it unites the "saving souls" and "saving forests" (understand well, it's not about trees, but the whole material creation clamped together in a catchphrase) attitudes in the mystery of Incarnation.
  - bandie91 4y ago
    standing on a viewpoint of ca. "the cause of everything is a spaceless, timeless, immaterial, powerful, intelligent, personal being" (ie. the pilosophers' God) does not entail the Abrahamic religions' image of God directly, nor an afterlife of humans, nor a right to self defence, nor commission of evangelization nor jihad.

Aperocky 4y ago

This is YOLO on the universe level.

ye-olde-sysrq 4y ago

"How can the net amount of entropy of the universe be massively decreased?"

andai 4y ago
For the uninitiated: https://users.ece.cmu.edu/~gamvrosi/thelastq.html https://users.ece.cmu.edu/~gamvrosi/thelastq.html
- dontwearitout 4y ago
  Thank you for sharing this!
MichaelZuo 4y ago
What does 'net amount of entropy' mean?
- ye-olde-sysrq 4y ago
  You can already decrease entropy locally, but net for the entire universe, entropy (as far as we can tell...) always increases monotonically. And any action you take to decrease local entropy still actually increases it in total. So "The Last Question" is also basically asking - "how can we avoid the heat death of the universe?". And phrased yet again differently: "Once all the stars burn out and all the uranium is fissioned and the coal burned and the universe is just a homogenous 5 degree kelvin soup of [I'm sure some physicist could tell me whatever fundamental particle it'll be that composes this soup] - what then? Is that just it?"
  - twawaaay 4y ago
    Once all stars die you will be able to live very long off of the heat of dead stars as they slowly cool off to background temperature. And once those stars are completely cold, you can start converting their mass into energy by dropping them into black holes, piece by piece. And once you dropped all matter you could into black holes you could live off merging black holes. And once you merged black holes you could live off of the black hole radiation until all black holes evaporate. But this would be if the Universe wasn't expanding at a growing rate. If the Universe is truly expanding at an ever accelerating pace there will come a Big Rip which will cause every fundamental particle to get further from all other particles at speeds faster than light. And then matter as we know it will cease to exist.

bena 4y ago

This sort of thing always fascinates me. This is all true and it absolutely does not matter. The thought of the universe sitting essentially idle for 10^86 years seems like it should feel wasteful. But why? Wasting what? Does our consciousness imbue the universe with any special quality? It's all so weird. Even some of our most fantastical science fiction only projects out a few millennia. Star Trek gets to the 31st century (or 3000s). Foundation is at least 12,000 years in the future. Dune takes place from about 23,000 to about 28,000. Warhammer 40k gets its name from the fact it takes place in the 40,000s. The Time Machine reaches to the 800,000s for the majority of its action. Red Dwarf is set the furthest at 3,000,000-ish. All of which fall way short of even 1 billion years. The Andromeda and Milky Way galaxies aren't scheduled to meet up for another 5 billion. We aren't even a blip.

lanna 4y ago
> The thought of the universe sitting essentially idle for 10^86 years 10^100 years minus 10^14 years is not 10^86 years. It is roughly 10^100 years.
badcppdev 4y ago
Small correction to your maths but not your sentiment. 10^100 years - 10^14 years = approx. 10^100 years In the same way that: 10^6 - 10^3 = 1,000,000 - 1000 = 999,000 which is more or less approx. 10^6 Edit: Although this is one of those relatively uncommon situations where it doesn't really matter if you're off by 100 trillion years.
- bena 4y ago
  True enough. I honestly did not care enough to do anything but the most cursory attempt at math due to the scale involved. 10^14 years and 10^100 are effectively equal compared to even our entire species current lifespan.
  - Taywee 4y ago
    Yeah, it can be boiled down to "there will be stars for longer than you can fathom, then there won't be stars for longer than you can fathom". It's hard to really feel much about different timespans that are all "forever" relative to the entirety of human existence.

thisismyswamp 4y ago

This is meaningless, nothing about those numbers matters neither does it say anything conclusive about the nature of reality. It's just our best guess right now, and we are very early.

Aperocky 4y ago
I find this interesting about human nature, that is in the want to believe in something eternal. Even if current theory about Universe is proven correct, it will most likely have no effect whatsoever on current human lifetimes. But doesn't preclude us from wanting to believe that the universe is eternal and constant, that there will be flashes of life and activity 10^50 years down the line.
- thisismyswamp 4y ago
  I find the reverse interesting - this anti-conventional desire to reduce scary questions to meaningless quantities in order to intellectually one up everyone else.
  - jacquesm 4y ago
    Or, maybe they're just right.
    - edgyquant 4y ago
      Impossible to know but seemingly illogical.
didntreadarticl 4y ago
True, there are other options https://en.wikipedia.org/wiki/Big_Crunch https://en.wikipedia.org/wiki/Big_Crunch https://en.wikipedia.org/wiki/Big_Rip https://en.wikipedia.org/wiki/Big_Rip https://en.wikipedia.org/wiki/False_vacuum_decay https://en.wikipedia.org/wiki/False_vacuum_decay etc

__MatrixMan__ 4y ago

If this haunts your dreams, consider "The Life of the Cosmos" By Lee Smolin, as antidote. In that book he proposes that each of those black holes has a child universe associated with it, some of which have sets of physical constants that allow for grandchildren. It's a fun read.