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aren't people (and all living organisms) the quintessential example of a local decrease in entropy that results in greater overall entropy? we are highly ordere

aren't people (and all living organisms) the quintessential example of a local decrease in entropy that results in greater overall entropy? we are highly ordered groupings of matter but we're really great at churning about the matter and energy around us and we eventually decompose too.

protonfish 10y ago
No more so than the wall in the previous example that created a local decrease of entropy.
jrapdx3 10y ago
A living organism is of course a noble endeavor standing against the tide of entropy. But it can do so only with significant influx of energy extracted from its external environment. The cost of constructing such an elaborate order of matter is paid by disorder elsewhere. As we know, the living stance can be maintained for only a relatively short time, after which it rapidly decomposes to background entropy. Interesting to speculate, as living beings we are chock full of "micro-environments", there could be exceptions to the laws of nature as we've understood them that could account for certain mysteries of biological nature.
- dogma1138 10y ago
  Any living organism is high entropy there are considerably lower entropy states for the molecules that make up your body to hold than the arrangement that makes you, you. A living organism also increases the entropy of the environment.
- civilian 10y ago
  We're not standing against the tide of entropy. If we're going to use a water metaphor, let's talk about a dam or a water wheel. Life is capturing energy and redirecting it-- we're still increasing entropy, but we're directing it in such a way that allows us to have some semblance of order. We aren't trying to resist anything, we dance in the expenditure of entropy.
bbctol 10y ago
Sure, but the above point was indicating that even a closed system is capable of decreasing in entropy, according to all other physical laws; it's just that the more complex the system is, the probability of the decrease declines rapidly to near zero.
JumpCrisscross 10y ago
> aren't people (and all living organisms) the quintessential example of a local decrease in entropy that results in greater overall entropy Complexity is orthogonal to entropy. The aforementioned barrier-separated box is high in entropy but simple. Upon lifting the barrier, a description of the gas front moving into the vacuum is enormously complex. It is also lower in entropy than the previous, barrier-separated state. Finally, when the gas is diffuse and entropy at its maximum, complexity dips back down. Life is complex. Plants turn solar radiation into complex living structures; they also diffuse waste heat. Animals eat those plants, make more complex stuff, and generate more diffuse waste heat.
- jbpetersen 10y ago
  Is there a way to quantify complexity in that sense?
  - wyager 10y ago
    No, because the GP is wrong. He claimed > The aforementioned barrier-separated box is high in entropy but simple. This isn't true in any meaningful objective sense; representing the exact state of the system in some basis (e.g. the position or momentum states of all particles in the system) requires a huge amount of information, corresponding to the entropy. The GP only said it's a "simple" system because we (for arbitrary reasons) don't really care very much about the position of each gas molecule. We as humans are satisfied with describing the system in terms of bulk statistical characteristics like temperature and pressure. However, we would be unsatisfied doing the same thing with a similarly information-rich system such as a microprocessor, because now the bulk characteristics of the system aren't sufficient information to describe the characteristics that humans care about. "Simplicity" or "complexity" as described by the GP is not a physical quantity; it's a reflection of which precise dynamical behavior we happen to care about. You could probably find all sorts of heuristics that generally match with human intuition, but in the end it's up to opinion.
  - eli_gottlieb 10y ago
    Shannon entropy is the expectation of Kolmogorov complexity, although I don't remember how Shannon entropy relates to Boltzmann entropy.
ThePhysicist 10y ago
Yes absolutely! Life is actually a way to increase entropy as it harnesses chemical energy in systems that otherwise wouldn't be able to reach a lower energy state by themselves.
- ddalex 10y ago
  Isn't it the other way around? Life decreases local entropy?
  - ThePhysicist 10y ago
    Yes but globally entropy increases faster than would be possible without life :)
deleted 10y ago
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mehwoot 10y ago
aren't people (and all living organisms) the quintessential example of a local decrease in entropy that results in greater overall entropy? Yes, but that's not what the person you replied to was saying. They were pointing out that there can be a global, absolute decrease in entropy, it's just statistically very unlikely.

protonfish 10y ago

No more so than the wall in the previous example that created a local decrease of entropy.

jrapdx3 10y ago

A living organism is of course a noble endeavor standing against the tide of entropy. But it can do so only with significant influx of energy extracted from its external environment. The cost of constructing such an elaborate order of matter is paid by disorder elsewhere. As we know, the living stance can be maintained for only a relatively short time, after which it rapidly decomposes to background entropy. Interesting to speculate, as living beings we are chock full of "micro-environments", there could be exceptions to the laws of nature as we've understood them that could account for certain mysteries of biological nature.

dogma1138 10y ago
Any living organism is high entropy there are considerably lower entropy states for the molecules that make up your body to hold than the arrangement that makes you, you. A living organism also increases the entropy of the environment.
civilian 10y ago
We're not standing against the tide of entropy. If we're going to use a water metaphor, let's talk about a dam or a water wheel. Life is capturing energy and redirecting it-- we're still increasing entropy, but we're directing it in such a way that allows us to have some semblance of order. We aren't trying to resist anything, we dance in the expenditure of entropy.

bbctol 10y ago

Sure, but the above point was indicating that even a closed system is capable of decreasing in entropy, according to all other physical laws; it's just that the more complex the system is, the probability of the decrease declines rapidly to near zero.

JumpCrisscross 10y ago

> aren't people (and all living organisms) the quintessential example of a local decrease in entropy that results in greater overall entropy Complexity is orthogonal to entropy. The aforementioned barrier-separated box is high in entropy but simple. Upon lifting the barrier, a description of the gas front moving into the vacuum is enormously complex. It is also lower in entropy than the previous, barrier-separated state. Finally, when the gas is diffuse and entropy at its maximum, complexity dips back down. Life is complex. Plants turn solar radiation into complex living structures; they also diffuse waste heat. Animals eat those plants, make more complex stuff, and generate more diffuse waste heat.

jbpetersen 10y ago
Is there a way to quantify complexity in that sense?
- wyager 10y ago
  No, because the GP is wrong. He claimed > The aforementioned barrier-separated box is high in entropy but simple. This isn't true in any meaningful objective sense; representing the exact state of the system in some basis (e.g. the position or momentum states of all particles in the system) requires a huge amount of information, corresponding to the entropy. The GP only said it's a "simple" system because we (for arbitrary reasons) don't really care very much about the position of each gas molecule. We as humans are satisfied with describing the system in terms of bulk statistical characteristics like temperature and pressure. However, we would be unsatisfied doing the same thing with a similarly information-rich system such as a microprocessor, because now the bulk characteristics of the system aren't sufficient information to describe the characteristics that humans care about. "Simplicity" or "complexity" as described by the GP is not a physical quantity; it's a reflection of which precise dynamical behavior we happen to care about. You could probably find all sorts of heuristics that generally match with human intuition, but in the end it's up to opinion.
- eli_gottlieb 10y ago
  Shannon entropy is the expectation of Kolmogorov complexity, although I don't remember how Shannon entropy relates to Boltzmann entropy.

ThePhysicist 10y ago

Yes absolutely! Life is actually a way to increase entropy as it harnesses chemical energy in systems that otherwise wouldn't be able to reach a lower energy state by themselves.

ddalex 10y ago
Isn't it the other way around? Life decreases local entropy?
- ThePhysicist 10y ago
  Yes but globally entropy increases faster than would be possible without life :)

deleted 10y ago

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mehwoot 10y ago

aren't people (and all living organisms) the quintessential example of a local decrease in entropy that results in greater overall entropy? Yes, but that's not what the person you replied to was saying. They were pointing out that there can be a global, absolute decrease in entropy, it's just statistically very unlikely.