How small does sub-atomic universe go?

[ucf-fisher21]

Hi everybody,

I was just wondering if humans have discovered the fundamental nature of matter (or energy). If not, could matter possibly be made up of an infinite regress of particles?

I've heard that quarks are what make up protons and nuetrons. What about electrons? Are they fundmental or can you break it down farther?

 

[DrChinese]

Hi everybody,

I was just wondering if humans have discovered the fundamental nature of matter (or energy). If not, could matter possibly be made up of an infinite regress of particles?

I've heard that quarks are what make up protons and nuetrons. What about electrons? Are they fundmental or can you break it down farther?

Electrons are fundamental. They act as point particles (no internal structure) based on experiments. So in this respect, theory and experiment currently agree. Electrons and other fundamental particles exhibit quantum behavior, which is a very strong indicator that there is no deeper level.

If you would like to postulate that there is a deeper level, you will need to come up with a theory that explains what goes on and how it can be tested to determine it is accurate.

 

[jtbell]

Electrons are fundamental.

... as far as we know. (I know you know this; I just wanted to make it clear to the original poster. Everything we know is "as far as we know," so we tend to take it as implicit in everything we say.)

I'd like to add that some physicists have speculated about a possible next level of particles that would combine to form electrons, quarks, etc. Two names that come to my mind are "rishons" and "preons." But as far as I know, these speculations / theories haven't (yet) predicted anything new about particles that could be verified experimentally.