> we've known for a long time that atoms are not indivisible.
I do not agree with your statement that "we've known for a long time that atoms are not indivisible." Lucretius makes very clear that atoms are forever indivisible entities. So, _by definition_, we call an indivisible object an atom. If it is divisible it is not an atom, according to the original definition of the word.
What happened is that, physicists named an object an "atom" and when they resolved that object they named "atom" into its constituent parts, they claimed to have divided an indivisible atom. No. This is only a play on words.
Unfortunately, we see this process of loading old words with new meanings in physics all the time. No definition is sacred in physics. As you wrote, "In modern usage, 'materialism' is synonymous with 'physicalism'." This simply means that physicists changed the meaning of the word "material."
This process confuses me a lot. I even have a short essay about why physics must be semantics.
I agree that terminology is especially fickle in physics, and it can be very confusing. Words need to be co-opted in order to discuss the objects of a new theory, and often they are simply chosen by rough analogy. The "mass" of Newton's spacetime is not the "mass" of Einstein's relativity. The "spin" of an electron is not the same as the spin of a car's wheel.
John Stewart Bell has a nice quotation about this when discussing the use of the word "measurement" in quantum theory:
> Take for example the “strangeness”, “charm”, and “beauty” of elementary particle physics. No one is taken in by this “baby talk”. ... Would that it were so with “measurement”. But in fact the word has had such a damaging effect on the discussion, that I think it should now be banned altogether in quantum mechanics.
As for atomism more broadly, now that I think about it there are some modern theoretical physicists with ideas about the discretisation of spacetime, for example: https://arxiv.org/abs/1312.2852
I do not agree with your statement that "we've known for a long time that atoms are not indivisible." Lucretius makes very clear that atoms are forever indivisible entities. So, _by definition_, we call an indivisible object an atom. If it is divisible it is not an atom, according to the original definition of the word.
What happened is that, physicists named an object an "atom" and when they resolved that object they named "atom" into its constituent parts, they claimed to have divided an indivisible atom. No. This is only a play on words.
Unfortunately, we see this process of loading old words with new meanings in physics all the time. No definition is sacred in physics. As you wrote, "In modern usage, 'materialism' is synonymous with 'physicalism'." This simply means that physicists changed the meaning of the word "material."
This process confuses me a lot. I even have a short essay about why physics must be semantics.
https://docs.google.com/presentation/d/1lV91S8enG4TqkxfO3XkA...