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What if we could use the notion of entropy in a definition of life? Living things use energy to prevent entropy (decay?) while they are alive. On the other ha

What if we could use the notion of entropy in a definition of life? Living things use energy to prevent entropy (decay?) while they are alive. On the other hand, natural, non-living processes do no such thing, and increase entropy as governed by the law of thermodynamics. We could also use criteria such as growth, reaction to stimuli, and reproduction. However, crystalline structures also grow and chemical processes may produce more of a certain molecule. All of those seek some energy minimizing equilibrium without any mitigating mechanisms.

woodandsteel 9y ago
The problem with that definition is there are other types of systems that do that. But it certainly is an essential part of the definition.
jwilliams 9y ago
That's true - and it's been used in a few contexts. The issue is the context. i.e. Living systems do take in energy and organize. However, if you make the box a little bigger, it's still subject to entropy. However, even drawing the box/context is useful!
snowwrestler 9y ago
You can't beat entropy, or prevent it. All you can do is change its distribution. So, one way to look at living things is that each one is a local depression in entropy. But because you can't make something from nothing, each living thing has to broadly increase entropy in their environment, in order to decrease it locally. Thus if we envision entropy as a surface, a living thing is not a depression from a flat plane, but rather more like a hill with a steep depression in the middle. But again, since you can't have something from nothing, life can't arise from an environment of maximum entropy. In order for life to come into being, local entropy must be low enough for a hill to develop. This is where the entropic definition gets into trouble, because the local low-entropy environment around here is provided by the sun. And if you define life as any local depression of entropy, then it raises the question of whether the sun is alive. Maybe it's better to think of life as a system, not an attribute. To use an analogy, you wouldn't look at a single wave in a rapid in isolation, and wonder what it is. Without the broader context of the river, you'll never understand how the wave came to be there. If every living thing is a like a ripple in the local entropic surface, we can point to individuals, but could only really understand them if we consider the whole picture of the solar system.

woodandsteel 9y ago

The problem with that definition is there are other types of systems that do that. But it certainly is an essential part of the definition.

jwilliams 9y ago

That's true - and it's been used in a few contexts. The issue is the context. i.e. Living systems do take in energy and organize. However, if you make the box a little bigger, it's still subject to entropy. However, even drawing the box/context is useful!

snowwrestler 9y ago

You can't beat entropy, or prevent it. All you can do is change its distribution. So, one way to look at living things is that each one is a local depression in entropy. But because you can't make something from nothing, each living thing has to broadly increase entropy in their environment, in order to decrease it locally. Thus if we envision entropy as a surface, a living thing is not a depression from a flat plane, but rather more like a hill with a steep depression in the middle. But again, since you can't have something from nothing, life can't arise from an environment of maximum entropy. In order for life to come into being, local entropy must be low enough for a hill to develop. This is where the entropic definition gets into trouble, because the local low-entropy environment around here is provided by the sun. And if you define life as any local depression of entropy, then it raises the question of whether the sun is alive. Maybe it's better to think of life as a system, not an attribute. To use an analogy, you wouldn't look at a single wave in a rapid in isolation, and wonder what it is. Without the broader context of the river, you'll never understand how the wave came to be there. If every living thing is a like a ripple in the local entropic surface, we can point to individuals, but could only really understand them if we consider the whole picture of the solar system.