Entropy explained, with sheep (2016)

Cold ice, in an environment that doesn't supply energy to the ice, will not explore microstates at any notable pace, and thus will not melt.

I don't think it makes any prediction about what will happen when cooling water, because the freezing reaction is related to the specific chemistry of water molecules. The only prediction is that any macrostate that gets newly entered into is less likely to change, because of the relatively low energy state of the system (compared to the energy required to break the newly formed bonds of the crystalline form.

What did I miss/get wrong?

this is getting a bit meta, maybe even off-topic. But I think this is fairly simple to explain: you can't remember states you haven't been in. Generalized memory implies some record of a state that has occured - states that have not occured cannot be remembered. The problem is that memory of types that we are familiar with (human, written, computer) all involve macrostates, not microstates. And increasing entropy (aka "more probable things are more likely to happen") mean that there is asymmetry at the macrostate level, and thus in memory.

A memory system that only recorded microstates would, I suggest, have no concept of time, and a much reduced notion of causality. There may be some statistical patterns that could be observed and could perhaps be "strong" enough to infer that "after state N we frequently end up in state P", but the sheer number of states would likely interfere with this.

There's also the timescale problem. A memory system that operates on the timescales of typical human experience will notice relatively constant change in much of the world, as macrostates come and go. But a memory system that operates at, say, geological timescales won't record many macrostate changes at all, and will tend to indicate that almost nothing happens in the world. All those macrostates ("tables", "chairs", "houses", "books") that came and went without being noticed form no part of this system's memory of the world. Of course, there are processes still taking place (new macrostates made up of even more vast microstates), but these going to be even more directional/asymmetric.

The one part of this view that leaves me a little confused is that at very short timescales, the unchanging nature of many macrostates is echoed in relatively unchanging microstates for most solids. The piece of metal that makes your isn't changing macrostates at any appreciable pace (which is why its eventual wearing out forms an asymmetric experience of time for us), but it also isn't changing microstates in any notable way either. I find this confusing.

Now explain this: when the sheep are cooped up in one box you can extract energy from the system. This becomes apparent if you imagine the boundary between the boxes is a fan. As the sheep move from what is a high pressure on one side to 0 pressure on the other they will move the fan. Attach a generator to the fan, and you get energy out.

This configuration, with high pressure on the side low on the other, will happen every so often through random chance. Admittedly not very often, in fact so rarely it's useless to us. But in principle we have a perpetual motion machine.

We don't, of course. But why not?

And more to the point is the 2nd law nothing more than a statement of averages? By which I mean "order always tends towards disorder" is in fact false. We will every so often see order arise from disorder. So the 2nd law is not really a hard and fast law, any more then "you always loose when gambling at the casino" is a hard and fast law.

Also, who determines what a 'macroscopic variable' is? Why do there only seem to be 3 for gassess (V, T, P?)