Quantum Physics

[Grrrrr]

I've always enjoyed reading and learning about Quantum Physics and General Relativity and with all the talk of the LHC i'm determined to understand as much of it as possible! I've done quite a lot of reading on wikipedia as well as reading Brian Greene's Elegant Universe but sometimes written text is a poor substitute for a good teacher. So i have some questions!

The photon is the force carrier of the electromagnetic force, the W&Z bosons of the Weak Force and Gluons of the strong force. That's easy enough to understand written like that but i can't quite get my head around how the actual process works.

This is how i imagine it to work, so please tell me if i am wrong!

Take for example a 'gun' that can fire 2 electrons parallel to each other, simultaneously. The electrons both have negative charge and repel each other causing them to move apart. So according to the above do the electrons both release a photon in the direction of each other causing them to move apart?

Suppose the gun fires an electron and a proton, they have opposite charges and will move together. In this case will the 2 particles release a photon away from the other particle, thus causing them to move together?


Hopefully this thread will turn into a question and answer session on quantum physics so i'd appreciate it if anyone without an interest in the subject could stay out of the thread. Thanks!

 

[Grrrrr]

They exchange "virtual" particles - no "real" photons are created or released etc.

http://en.wikipedia.org/wiki/Force_carrier
http://en.wikipedia.org/wiki/Virtual_particle

I've just read the virtual particle article and it explains the exact situation i just posed

From wiki:

In the image above and to the right, the solid lines correspond to real particles (of momentum p1 and so on), while the dotted line corresponds to a virtual particle carrying momentum k. For example, if the solid lines were to correspond to electrons interacting by means of the electromagnetic interaction, the dotted line would correspond to the exchange of a virtual photon. In the case of interacting nucleons, the dotted line would be a virtual pion. In the case of quarks interacting by means of the strong force, the dotted line would be a virtual gluon, and so on.

More Questions soon!

 

[Grrrrr]

But if they were emitting photons i think we'd be able to detect it wouldn't we?

From the same article as my last post

In practice, a clear distinction can be made: real photons are detected as individual particles in particle detectors, whereas virtual photons are not directly detected; only their average or side-effects may be noticed, in the form of forces or (in modern language) interactions between particles.

 

[Grrrrr]

Edit: The Feynman diagram have always confused me, since again mechanical intuition prevails - if there is an exchange of momentum, such as in balls colliding with each other, then how does it give rise to an attractive force. It seems to me that they would always cause repulsion.

I was pondering this also.

Also, photos clearly exist as particles that we can detect as well as being 'virtual particles'. Can the same be said of bosons and gluons or do they only exist as virtual particles?

 

[Grrrrr]

Very interesting, i appreciate your input

With regards "emitting a negative-virtual-photon towards each other" as you put it, is this a good way of describing what happens, or what actually happens? Am i punching above my weight trying to figure all this out?