Not sure I would describe physics as the truest form of materialism. It's just a tool or science for describing things. Maybe truest measure of reality according to materialism in that it is capable of pinpointing the most fundamental elements that compose the world around us? I'm not sure where you're going with this question.
Sorry about that. It is not what I am saying, but what frustratingly, seems to be the prevailing understanding of materialism among the faithful.
It seems to me that discussions about materialism so often devolve into discussion the minutiae of high energy physics. I think this is a consequence of reducing Materialism to some stick-figure cartoon like "Materialism says everything is just made up of atoms".
Maybe you think physics is not the truest measure? But materialism assumes only material things exist.
I say that this is a caricature reduction of materialism on par with caricature reductions of religion like Russell's Teapot. It serves only as a cheap excuse not to engage with the topic.
Here's an illustration of why materialism goes far, far beyond "only material things exist":
I believe most religions would term a person who is primarily interested in money a "materialist".
So what is money? It is not the bank notes or credit cards - those are symbols of money. It is not the balance sheets or gold reserves, these are, again, symbols of money.
Money has no material existence. But it is causal, it has undeniable causal power in our reality, it iis very, very real! Think of all the massive projects set in motion by the completely immaterial, non-existent, but very real, and thoroughly materialist concept of money.
So materialism, even when used as a derogative to indicate wealth, cannot be said to view reality only in terms of physically existing objects.
One pithy definition of Materialism is that "existence precedes essence". I like that, but it is awfully abstract. The German writer Berthold Brecht made it more concrete with his one-liner of "Grub first, the Ethics" ("Erst kommt das Fressen, dann kommt die Moral"). Or, to put it into less crass terms,
consciousness arises from noticing "I exist", is the materialist position. I'd like to point out how this is quite the opposite of Descarte's "I think, therefore I am", which puts ideas, thoughts, before existence, and indeed apart from existence, creating a dualism of ideas and matter which is very reminiscent of religious concepts of a spiritual world existing apart from the physical one.
Materialism, to my understanding, is very opposed to dualism. Mind and matter are not two separate realms of existence. Our minds are not "trapped" in material existence - our minds have material existence.
I'm still caught up on the words physics as truest form of materialism. When I think of forms of materialism, I think of different ideologies within the worldview of materialists everywhere.
Yes, right? There is so much more to Materialism than reducing everything to a Lego world of quarks and leptons.