This quote is by Naty1 from another thread. I wanted to expand on it, but it would have been off-topic. "They" refers to strings. I have always wondered about this. Is it true that the troublesome infinities which lead to the need for renormalization and such are the result of particles being infinitesimally small? The reason I'm asking this is that apparently the Standard Model requires that elementary particles be infinitesimally small points. Does this mean literally infinitesimal? Sometimes I see the term "point" and other times "point-like" which seems to leave some room for some size. I just cannot philosophically wrap my mind around any "thing" (even if the "thing" is just a field disturbance) that has absolutely no dimension at all, and it also seems to lead to all kinds of quantum confusion at planck lengths. It's easier for me to accept 11 dimensions that that... I think that that is one of the big reasons that, for me, a non physicist, String Theory is so appealing at least on a qualitative level, because it allows a particle as having some finite size, about a planck length, which also renders the sub-planck quantum stuff irrelevant. I understand that the SM is spectacularly successful, but I don't quite understand why this requirement is so important (probably because I don't understand the math). Is this requirement strictly a mathematical necessity to make the formaulae work, or is it reasonable to accept the idea of infinity or infinitely small as being physically real?