how can photons and other elementary particles have 0 dimension yet comprise objects that are extended in 3 dimensions?



From my limited understanding of physics, it seems like since a photon has 0 dimension, it should reflect off 0% of the surface of an object, because its cross section that collided with the surface is 0 units wide. That would mean an infinite number of photons would be required to capture the features of any object at all, which seems absurd and impossible.

In: Physics

A photon acts like a wave, a particle, and a probability distribution (like an electron), meaning that it is not 0 dimensions. A photon has just enough force behind it that when a lot of photons are working together, they can propel objects (look into solar sails). From my understanding, photons are 1-dimension, in that they are a single point (not sphere) that expresses itself as a wave. Think “How thick is a wave of sound?” It doesn’t have a thickness/volume, but it is present along its line.

If you look into String Theory, it’s main basis is that the universe is made of particles that aren’t 3-dimensional. It is a “string” like a rubber band on a 2-d plain. When that band is “twanged” or shaken, it vibrates into a 3-dimension shape (smaller than quarks, which are what protons/etc are made of). The frequency of the “twang” is what is responsible for different particles being observed/formed. (This is ONE theory of the universe. When following String Theory, there are 10 (+ ?) dimensions.)

You know how in school they teach you something in lower grade and tell you “what they taught you is partially correct, but mostly wrong” when you get to a higher grade? Yeah this is one of those situations.

Essentially, when you go wayyyyy down on the scale of sizes to elemental particles in the standard model, they can only be detected from charge and mass. In terms of size, there are researches that tells us “they are smaller than this, we still can’t figure out just how small they are”. So, as a pragmatic way of dealing with it, people just consider them as points since their sizes are insignificant when compared to the distance which they interact with other particles.

And then there’s instances like “photons” and “forces” where they are technically mathematic representations of “smallest unit of energy” with no mass but exhibit properties of both waves and particles. Afaik, they exist as a stand in to explain how things work, like how photon is the “particle version” of light to give sense on how reflection works.

So yeah, the ELI5 for that is “they aren’t technically 0 dimension, just small enough we don’t/can’t care to mention it” or more accurately, “we genuinely don’t fucking know what it looks like when things get this small, and we could be completely wrong the entire time, the model we use now just happens to work for current purposes so we stick with that”.