My friend and I came to wondering if there is indisputable proof that electrons exist? Sure, I can sit in a physics class and talk about their speed, mass, spin, etc... but how do I know that all that is real? How do we know that there isn't something else in their place that functions similarly and therefore gives us the results we expect, but at the same time explains some of the problem areas of physics? I am under the impression that no one has ever seen an electron or any other, smaller particle. If this is the case, isn't there the possibility that we're a little off base?