What is matter?

[Demiurge]

From the point of view of quantum physics... Could physicists agree what matter is?

We see it, we describe it yet it resists intuitive understanding.

Is matter really just energy and measurement, decoherence, splitting, whatever process that brings out single outcomes aka "matter"?

 

[PeterDonis]

From the point of view of quantum physics... Could physicists agree what matter is?

"Matter" is a word. Physics is not done in words. It's done in math. So what the word "matter" means depends on what thing in the math you use that word to refer to.

 

[DaveC426913]

I think we've explored this before in another thread.

I offered the ready-n-ready definition that - with a few notable exceptions - matter encompasses the gamut of fermionic particles - the particles that obey Pauli Exclusion, and therefore "take up room" (in the way that, say, light does not).

Helium 3 is one of those notable exceptions that is matter yet does not obey PEP.