Steve Dodge on Nostr: StartsWithABang I second Doug’s framing here—I would start by introducing the ...

StartsWithABang (npub10lr…nszn)

I second Doug’s framing here—I would start by introducing the solid-liquid-gas distinction as familiar but in need of a more precise definition. I would emphasize that the key is to recognize that the most important distinction between these phases is that they are separated by a phase *transition*.

Then I would note that the liquid-gas transition can be avoided altogether in the P-T phase diagram, and point out that this is possible because liquid and gas have the same *symmetry*. I’d then explain that the modern classification of matter prioritizes symmetry, and we’re off to the races with popular introductions to Landau theory, the metal-insulator transition, and topology.

Another thing I would want to mention is that different ground-state symmetries imply different excited states, so crystalline solids have phonons, ferromagnets have magnons, etc. When you add topology, you can get even weirder excitations, with fractional charges such as e/3, or (in principle) quantum statistics that are intermediate between fermionic and bosonic.

I took a look at the Wikipedia entry for “state of matter” and it is a hot mess, suggesting that maybe we should accept that its meaning depends on the context. I don’t really object to the solid-liquid-gas-plasma+ framework, but I don’t see anything fundamental about it.

Lastly, I think a much more important critique of Nayak’s claim is that it remains inconclusive!