If you go deep enough in physics, you don't have "wood". You just have a wavefunction. The wavefunction evolves with time in "classical" QM physics, and just exists statically in timeless physics.

And "the same thing" doesn't mean much, since there is nothing like "this electron" but only "one electron".

Saying that a piece of wood changed is an upper-level concept, which you can't directly define in fundamental physics, but only approximates (like "pressure", or "wood", or "liquid"). The way you define your high level approximation doesn't really need to know if the lower level is continuous or not. The same way you won't define "liquid" differently just because we discovered that protons are not indivisible, but made of quarks.

Of course, lower level can be relevant : for example the fact there is no such thing as "this electron" contributes to saying that personal identity depends of configuration more than of "the same matter". But it's only a minor argument towards it, for me.

[anonymous]8y0

If you go deep enough in physics, you don't have "wood". You just have a wavefunction.

Fair enough, but surely the idea is to explain wood and the changes therein by reference to more fundamental physics. So even if the idea of change doesn't show up at the very most fundamental levels, there must be some level at which change becomes a subject of physics. Otherwise, I don't see how physics could profess to explain anything, since it would have nothing to do with empirical (and changable) phenomena.

Of course, lower level can be relevant : for

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