4 ms·

The main argument made, concerning the second law of thermodynamics can explain why we age but I am not sure it proves that aging is incurable. The second law o

by Iolaum 8y ago

The main argument made, concerning the second law of thermodynamics can explain why we age but I am not sure it proves that aging is incurable. The second law of thermodynamics says that entropy increases in closed systems. A human is not a closed system. The second law does not prevent a conceptual procedure where, through an operation/cure we decrease the entropy of a patient/human. Of necessity that procedure would produce a bigger increase of entropy in the environment with which the patient/human interacts, but that's not a problem. As an example of the above imagine a fetus 2 weeks old and a fetus 20 weeks old. The is much more order in the 20 week fetus, therefore less entropy. It's also easy to realise that the fetus is not a closed system since it interacts heavily with it's mother.

ijpoijpoihpiuoh 8y ago
Under the same argument made in the article, a room can never be tidied. It can only become messier and messier. And yet, somehow, my house is set right every other Friday after the cleaning people come through. To me, it seems obvious that the second law is at most a contributory factor. The real reason we age is that indefinite longevity is energy-intensive and not favorable for the propagation of the information patterns in our genes. Our genes have optimized for propagation, because information patterns that didn't have died out or been dominated. Anything else, including whether you live a day beyond the minimum required to help your children propagate their genes, is ancillary. Here's a thought experiment. Imagine you created a niche where the minimum reproductive age were gradually raised by artificial means. I suspect that in such a niche, you'd begin to see adaptations that would lead to longer lifespans. If you ran the experiment long enough on a large enough population, I'd bet natural selection would figure out how to get the average lifespan well above its current level. We could try it on some small animals [ed: not bacteria, since they do not reproduce sexually and it would be infeasible] to figure out if this is true, but it's hard for me to imagine it isn't. (How much human suffering would be involved, and whether we'd even recognize the result of this process as human, is also beside the point!)
- Iolaum 8y ago
  A friend from the university used that line on his parents as an excuse for the state of his room. Luckily for him they didn't know enough physics to call him out on it because his room was not really a closed system.
  - saagarjha 8y ago
    Or spent long enough to think about why rooms can be cleaned each week?
  - Terr_ 8y ago
    Young Me: "Why clean it? It'll just get dirty again." My Dad: "Why feed you? You'll just get hungry again."
snowwrestler 8y ago
You can trade entropy for order, but that doesn't necessarily mean you can trade any entropy for a particular set of order, like making a specific older person young again, or keep a person young forever. I haven't read the full article yet but there's more to thermodynamics than just a see-saw of entropy and order; it is also a factor in chaotic systems and "time's arrow"--which is pretty deep mystery physics. Quantum mechanics works just as well in either direction, time-wise. Theoretically a photon doesn't experience time at all, and every electron is indistinguishable from another. But at our scale, many processes seem unpredictable and irreversible. Even if you could catch all the smoke a candle puts out, and you add energy to make a candle out of it, it wouldn't be the same candle. We can take a broken egg, use it fertilize grain, feed the grain to a chicken, and make a new egg... but we can't just put the broken egg directly together again. And it might be impossible, no matter what the available energy, to keep someone from aging. Beyond entropy and order, which are statistical concepts, aging is the matter of how the state of our body progresses. And managing state seems a lot harder than just measuring total aggregate order in a system.
philwelch 8y ago
You can only cheat the second law of thermodynamics by emitting your entropy on the rest of the universe, and assuming the universe is a closed system, then the heat death of the universe prophesied by the second law of thermodynamics still puts a hard upper limit on human lifespan. Which is basically the crux of this whole disagreement--sure, it's scientifically possible to live orders of magnitude than we currently live, but even if you live for a million years, you're just punting on the question of mortality, you're not answering it.

by Iolaum 8y ago

ijpoijpoihpiuoh 8y ago

Under the same argument made in the article, a room can never be tidied. It can only become messier and messier. And yet, somehow, my house is set right every other Friday after the cleaning people come through. To me, it seems obvious that the second law is at most a contributory factor. The real reason we age is that indefinite longevity is energy-intensive and not favorable for the propagation of the information patterns in our genes. Our genes have optimized for propagation, because information patterns that didn't have died out or been dominated. Anything else, including whether you live a day beyond the minimum required to help your children propagate their genes, is ancillary. Here's a thought experiment. Imagine you created a niche where the minimum reproductive age were gradually raised by artificial means. I suspect that in such a niche, you'd begin to see adaptations that would lead to longer lifespans. If you ran the experiment long enough on a large enough population, I'd bet natural selection would figure out how to get the average lifespan well above its current level. We could try it on some small animals [ed: not bacteria, since they do not reproduce sexually and it would be infeasible] to figure out if this is true, but it's hard for me to imagine it isn't. (How much human suffering would be involved, and whether we'd even recognize the result of this process as human, is also beside the point!)

Iolaum 8y ago
A friend from the university used that line on his parents as an excuse for the state of his room. Luckily for him they didn't know enough physics to call him out on it because his room was not really a closed system.
- saagarjha 8y ago
  Or spent long enough to think about why rooms can be cleaned each week?
- Terr_ 8y ago
  Young Me: "Why clean it? It'll just get dirty again." My Dad: "Why feed you? You'll just get hungry again."

snowwrestler 8y ago

You can trade entropy for order, but that doesn't necessarily mean you can trade any entropy for a particular set of order, like making a specific older person young again, or keep a person young forever. I haven't read the full article yet but there's more to thermodynamics than just a see-saw of entropy and order; it is also a factor in chaotic systems and "time's arrow"--which is pretty deep mystery physics. Quantum mechanics works just as well in either direction, time-wise. Theoretically a photon doesn't experience time at all, and every electron is indistinguishable from another. But at our scale, many processes seem unpredictable and irreversible. Even if you could catch all the smoke a candle puts out, and you add energy to make a candle out of it, it wouldn't be the same candle. We can take a broken egg, use it fertilize grain, feed the grain to a chicken, and make a new egg... but we can't just put the broken egg directly together again. And it might be impossible, no matter what the available energy, to keep someone from aging. Beyond entropy and order, which are statistical concepts, aging is the matter of how the state of our body progresses. And managing state seems a lot harder than just measuring total aggregate order in a system.

philwelch 8y ago

You can only cheat the second law of thermodynamics by emitting your entropy on the rest of the universe, and assuming the universe is a closed system, then the heat death of the universe prophesied by the second law of thermodynamics still puts a hard upper limit on human lifespan. Which is basically the crux of this whole disagreement--sure, it's scientifically possible to live orders of magnitude than we currently live, but even if you live for a million years, you're just punting on the question of mortality, you're not answering it.