5 ms·

"But Freeman Dyson has shown that, despite this, life could adapt to the ever-decreasing supply of ordered energy, and therefore could, in principle, continue f

by pingou 14y ago

"But Freeman Dyson has shown that, despite this, life could adapt to the ever-decreasing supply of ordered energy, and therefore could, in principle, continue forever". Does anyone knows what he's talking about ? Dyson's sphere ? Surely there's some energy loss involved in the process ? But if it's true I'm happy to learn that an intelligent lifeform can theoretically live forever.

Luc 14y ago
I think this may be referring to the insight that there won't be a heath death of the universe, due to gravity. Best I could find is here (a book review written by Dyson): http://www.nybooks.com/articles/archives/2011/mar/10/how-we-know/?pagination=false http://www.nybooks.com/articles/archives/2011/mar/10/how-we-... "Gravitation reverses the usual relation between energy and temperature. In the domain of astronomy, when heat flows from hotter to cooler objects, the hot objects get hotter and the cool objects get cooler. As a result, temperature differences in the astronomical universe tend to increase rather than decrease as time goes on. There is no final state of uniform temperature, and there is no heat death. Gravitation gives us a universe hospitable to life. Information and order can continue to grow for billions of years in the future, as they have evidently grown in the past."
- pingou 14y ago
  So no heat death, but every computation implies an energy loss, right ? Even with the help of gravity, how do you prevent energy from escaping in EM form ? Even a black hole evaporate if I recall correctly. So I can imagine we could live a loooong time, but indefinitely ? That sounds too good to be true to me, but I don't know much about the physic involved.
  - kamaal 14y ago
    >>So no heat death Unfortunately even if that is true, there is something called as entropy at play here. Also I would advice you to read Isaac Asimov's "The last question" once. One thing discussed in that book is how quickly human kind or an intelligent being can grow in population and energy consumption. So even before we reach the point of heat death, if we survive and move out to do the heavens. Then over time, we are likely to run out of resources and space eventually- may be even long before the heat death of the universe itself.
wcoenen 14y ago
He's talking about the ideas from Dyson's "Time Without End" lectures: http://www.aleph.se/Trans/Global/Omega/dyson.txt http://www.aleph.se/Trans/Global/Omega/dyson.txt
- pingou 14y ago
  Thank you, looks interesting, I'll have a look, I hope it's not too complicated for a layman like me.
kamaal 14y ago
For curiosity and entertainments sake, I would recommend anybody to read Isaac Asimov's "The Last Question". It can be read under 15 minutes and it a entertaining read on this subject and entropy in general. However for serious arguments sake, the whole problem in this question is "definition of life" itself. However even if we consider that heat death is inevitable and that we are assuming human beings to be around then. Then there are way bigger threats to our future than the heat death of the universe.
andyjohnson0 14y ago
This is Dyson's "eternal intelligence" scenario. A summary can be found at [1], but the details are in "Time without end: Physics and biology in an open universe" [2]. wcoenen very helpfully linked to a text version of this paper [3]. [1] http://en.wikipedia.org/wiki/Dyson%27s_eternal_intelligence http://en.wikipedia.org/wiki/Dyson%27s_eternal_intelligence [2] "Time without end: Physics and biology in an open universe", Reviews of Modern Physics, Vol. 51, Issue 3 (July 1979), pp. 447-460 [3] https://news.ycombinator.com/item?id=4777857 https://news.ycombinator.com/item?id=4777857
- bluedanieru 14y ago
  So, Achilles never caught up with that tortoise, after all.

by pingou 14y ago

Luc 14y ago

I think this may be referring to the insight that there won't be a heath death of the universe, due to gravity. Best I could find is here (a book review written by Dyson): http://www.nybooks.com/articles/archives/2011/mar/10/how-we-know/?pagination=false http://www.nybooks.com/articles/archives/2011/mar/10/how-we-... "Gravitation reverses the usual relation between energy and temperature. In the domain of astronomy, when heat flows from hotter to cooler objects, the hot objects get hotter and the cool objects get cooler. As a result, temperature differences in the astronomical universe tend to increase rather than decrease as time goes on. There is no final state of uniform temperature, and there is no heat death. Gravitation gives us a universe hospitable to life. Information and order can continue to grow for billions of years in the future, as they have evidently grown in the past."

pingou 14y ago
So no heat death, but every computation implies an energy loss, right ? Even with the help of gravity, how do you prevent energy from escaping in EM form ? Even a black hole evaporate if I recall correctly. So I can imagine we could live a loooong time, but indefinitely ? That sounds too good to be true to me, but I don't know much about the physic involved.
- kamaal 14y ago
  >>So no heat death Unfortunately even if that is true, there is something called as entropy at play here. Also I would advice you to read Isaac Asimov's "The last question" once. One thing discussed in that book is how quickly human kind or an intelligent being can grow in population and energy consumption. So even before we reach the point of heat death, if we survive and move out to do the heavens. Then over time, we are likely to run out of resources and space eventually- may be even long before the heat death of the universe itself.

wcoenen 14y ago

He's talking about the ideas from Dyson's "Time Without End" lectures: http://www.aleph.se/Trans/Global/Omega/dyson.txt http://www.aleph.se/Trans/Global/Omega/dyson.txt

pingou 14y ago
Thank you, looks interesting, I'll have a look, I hope it's not too complicated for a layman like me.

kamaal 14y ago

For curiosity and entertainments sake, I would recommend anybody to read Isaac Asimov's "The Last Question". It can be read under 15 minutes and it a entertaining read on this subject and entropy in general. However for serious arguments sake, the whole problem in this question is "definition of life" itself. However even if we consider that heat death is inevitable and that we are assuming human beings to be around then. Then there are way bigger threats to our future than the heat death of the universe.

andyjohnson0 14y ago

This is Dyson's "eternal intelligence" scenario. A summary can be found at [1], but the details are in "Time without end: Physics and biology in an open universe" [2]. wcoenen very helpfully linked to a text version of this paper [3]. [1] http://en.wikipedia.org/wiki/Dyson%27s_eternal_intelligence http://en.wikipedia.org/wiki/Dyson%27s_eternal_intelligence [2] "Time without end: Physics and biology in an open universe", Reviews of Modern Physics, Vol. 51, Issue 3 (July 1979), pp. 447-460 [3] https://news.ycombinator.com/item?id=4777857 https://news.ycombinator.com/item?id=4777857

bluedanieru 14y ago
So, Achilles never caught up with that tortoise, after all.