the point particle

[gib65]

I'm just wondering how physicists conceptualize the "point particle" - that is, the model of the fundamental particles that describes them as geometric points (or the size of geometric points). Are we supposed to imagine them literally as tiny points that couldn't logically be any smaller?

 

I have a bit of trouble with this because I can't imagine anything physically existing unless it had some extention to it. If it didn't extend in a certain dimension, it would be infinitely thin in the other two, and therefore could only exist as a geometric concept, not a tangible thing in the world. Maybe that's just me though.

 

I know this topic is somewhat philosophical, but I figured it had at least one foot in physics, so I put it in this section. If the mods feel differently, feel free to move it to the appropriate section.

[Klaynos]

A point particle, is a theoretical model of an infitesimmlly small dot.

 

They are not physically real, fundemental particles have a finite probability wave in which they exist. They are not point particles.

[Severian]

Fundamental particles are point particles, but it doesn't really mean what you think. A point particle is an object whose position eigenstate is a point. So if you measure its position you get a point (in principle - clearly it is limited by experimental precision).

 

Most of the time they are not in position eigenstates though, so they are smeared out.

[Klaynos]

Sorry me bad

[gib65]

Ah, that makes more sense to me now. Thanks.