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Comment by adrianN | Hacker News Reader

> The Second Law of Thermodynamics: The world tends towards disorder. That’s why your room becomes messier and messier over time

That's not how the second law works.

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the second law says that there are statistically (infinitely) many orders of magnitude more ways to be disordered than ordered, so the inescapable tendency is from order to disorder.

the same goes for a room. many orders of magnitude more ways of being disordered than ordered. it tends toward disorder without additional energy to keep it ordered.

Except there is a conscious entity driving the room towards an ordered state.

Speak for yourself

Quantum Mechanics: stuff that takes form only when observed. That's why you can't find your keys or phone sometimes, or plug in a USB cable. :D

It's much simpler to simulate your universe if we only have to render what you're observing. I remember the days when we had to keep deleting telescopes and microscopes until we had enough processing power. Trains caused a lot of scenery to pop in before the new algorithm - we tried telling customers that the increased speed would kill them.

This seems like a reasonable analogy. What about it do you feel is wrong?

You can tidy your room and the mess (that they mistake for entropy) would be reduced. The 2nd law of thermodynamics states that in an isolated system the entropy is always increasing (or at best constant), so the room analogy does not work.

Tidying it requires external energy, which is what is happening (unless the person stays in the room in which case the mess will become even bigger).

Tidying your room would be adding energy to the system, to make it tidy. This is still in line woth thermodynamics where adding energy can decrease entropy

You have to add energy to make it messy as well

"Tidy" is a subjective quality, not an objective physical one. It does take mental energy to tidy a room, and without that effort it will tend to get messy through use. As long as you don't confuse mental energy for physical energy and tidiness for entropy in the literal sense, then the analogy works surprisingly well.

The only reason your room gets messier and messier is because you are messy, there is no law and physics has nothing to do with it. It just makes you feel smarter because you can use "thermodynamic" in a sentence

Physics does have something to do with it. It takes less energy to leave a food plate on your night stand than to get up and bring it to the sink. It takes less energy to throw your clothes in a mess on a chair than to fold them and put them away. Then when you eventually clean everything up, you expend less energy than the sum of energies that it would have taken to keep it tidy. For example, you can make 1 trip with 4-5 plates and cups to put them away as opposed to 1 trip per item. So you turn an energy profit. Messiness is energy expenditure minimization.

You might ask why clean up at all. For most people there comes a time when the mess starts being distracting and once they start having to look for items, they start to expend more energy per action. So it makes sense to clean everything up and start over.

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