>What I'm saying is that "the entropy" doesn't exist outside of our minds. It's the product of our description of the thermodynamical system. Depending on the model that we think of we produce a different entropy.

This whole discussion is pointless. It kind of angers me that we dived into this pointless pedantic side quest. If this is all you're trying to say then clearly when I defined a custom macrostate then you already knew I knew this. Why bother arguing about useless details? I think you're not being entirely honest here. I think you were mistaken about entropy OR you have certain issues going on with you as you spent so much time pushing this pointless thread forward. But whatever.

>What I'm saying is that "the entropy" doesn't exist outside of our minds. It's the product of our description of the thermodynamical system. Depending on the model that we think of we produce a different entropy.

No offense but this is probably the worst way to describe it. I have a mathematical model of a projectile motion. The projectile motion is a product of my mind because I made up that model. This is a COMPLETELY pointless statement and is analogous to yours.

I think this is snobbery. Either you assumed I didn't know what entropy was and in your snobbery wanted to teach me with some "revelatory" counter examples (which wasted so much time) or YOU didn't know what entropy was and you're just not admitting it.

>There is a relationship that depends on what is the thermodynamical model used to describe the system.

Right before you wrote this you wrote: "entropy is not a physical property of (the microstate of) the system but a property of a particular (thermodynamical) description of the system" which is completely contradictory. There is no way for entropy to ONLY be about macrostate WHEN macrostate is defined in TERMS of microstates.

It's like saying Trees have nothing to with atoms because trees are made of wood. Well guess what? Wood is made out of atoms!

This whole line is contradictory.

>Theoretically I could make the entropy go as close to zero as I want by making the macrostate more and more detailed. Quantum thermodynamics is one case in which entropy is zero when a state is perfectly known.

Wow this whole conversation started because you wanted to make light of some pedantic detail. Yeah if you define macrostate as a microstate sure. But if you want to go pedantic we can, your statement is STILL incorrect in light of your new example. Entropy is not ALWAYS zero if you know position and velocity of the balls, simply because this is not ALWAYS the case.

There are counter examples to your ALWAYS qualifier which makes your statement definitively false.

>Coming back to your original question: https://news.ycombinator.com/item?id=33226742

You have not answered my question. You aren't getting it. Rising Entropy is just an example for illustrative purposes, entropy is simply a probabilistic phenomenon. The question is deeper then that and is about the nature of probability and reality itself.

>Only if we keep adding uncertainty / forgetting information as we go forward will entropy increase.

Bro. Forgetting stuff doesn't change entropy. We already agreed that entropy is independent of knowledge. Yes Entropy is defined generically in that it requires an additional definition of a macrostate in order for the equation to be fully utilized.... but it is still in this case independent of knowledge.

You could say that forgetting stuff requires you to use lower resolution macrostate models in practice but this independent of the theoretical equation and is just a really stupid and over-complicated way of describing it.

For example: you could say that the volume of a rectangular prism is wlh. If someone forgets h, does that change the volume of the prism? Only if that someone is an ass hole (aka philosopher). Don't be an ass hole. This kind of "knowledge" related stuff can literally be applied to everything and is a rabbit hole with no final destination. The heart of it lies deeper.