Nitpick: "Atoms are called atoms because they have no subdivisible parts".
Oops, it turns out we used the name too soon.
When people say "universe" these days they mean the "visible universe" (or maybe the visible universe plus the stuff we're sure is there, but that falls outside our light cone now) - and not the original definition of the word anymore.
Atoms having no subdivisible parts implies that there are parts at all. But it turns out all matter is just somewhat stable oscillations within an energy field and no real boundaries between one part and another, and certainly nothing resembling such at the scale of something as large as an atom. So again.. too early..
Oops, it turns out we used the name too soon.
When people say "universe" these days they mean the "visible universe" (or maybe the visible universe plus the stuff we're sure is there, but that falls outside our light cone now) - and not the original definition of the word anymore.
(Not that we have "found" anything else yet.)