Are there any units? If you take apples from a tree and put them together it's two, but are the singular apples really 1? You can always divide the apple into smaller pieces, until it's atoms, then protons and neutrons, then quarks, then something else... etc. And you can do the same to always make something bigger. Earth could be considered a unit, but you could always stack more earths to make it into a bigger unit infinitely? Is there a explanation for this?