Understanding Mediators and Contact Interactions in Quantum Mechanics

[eraemia]

Hello everyone, I am kind of new to this forum. If this post belongs elsewhere, please tell me, thanks.

1. What are mediators? Are they particles? Why does the four fundamental interactions each have one or more associated mediators? Moore (my textbook's author) writes: “Each interaction as one or more associated mediators that represent the interaction in quantum-mechanical calculations (what does this mean?). These calculations imagine a pair of particles interacting by exchanging mediators in a way that usually makes the mediators undetectable even in principle (I don’t understand this at all)” (11). So, the book also tells me that strong nuclear interaction associates with gluons (8 types); electromagnetic with photons; weak with vector bosons; and gravitational with graviton.

2. What are examples for each of the following contact interactions: friction interactions (which oppose the relative motion of the objects in contact); compression interactions (which seek to keep them from merging); and tension interactions (which oppose their separation) (Moore 13). The book gives no explanation as for how to identify these contact interactions. There are some examples, but I need a more complete definition or explanation or each so I am able to identify when these interactions occur.

Thanks for everyone's help!

 

[olgranpappy]

Hello everyone, I am kind of new to this forum. If this post belongs elsewhere, please tell me, thanks.

1. What are mediators? Are they particles? Why does the four fundamental interactions each have one or more associated mediators? Moore (my textbook's author) writes: “Each interaction as one or more associated mediators that represent the interaction in quantum-mechanical calculations (what does this mean?). These calculations imagine a pair of particles interacting by exchanging mediators in a way that usually makes the mediators undetectable even in principle (I don’t understand this at all)” (11). So, the book also tells me that strong nuclear interaction associates with gluons (8 types); electromagnetic with photons; weak with vector bosons; and gravitational with graviton.

I wouldn't worry about it too much if I were you just right now. At this level you can just treat knowledge of all those silly particles as tidbits of worthless trivia.

2. What are examples for each of the following contact interactions: friction interactions (which oppose the relative motion of the objects in contact); compression interactions (which seek to keep them from merging); and tension interactions (which oppose their separation) (Moore 13). The book gives no explanation as for how to identify these contact interactions.

He gives explanations in the parenthesis. For example, friction interactions (oppose relative motion of objects in contact)... like when Mr. Miyagi in the movie "The Karate Kid" rubs his hands back and forth together really fast to generate heat to heal Daniel-Son. That's friction. Two things rubbing on each other. That's what "relative motion of the objects in contact" means.

There are some examples, but I need a more complete definition or explanation or each so I am able to identify when these interactions occur.

Thanks for everyone's help!

 

[eraemia]

That's...somewhat helpful, thanks. But it doesn't help me solve any of my homework questions! -- https://www.physicsforums.com/showthread.php?p=1417814#post1417814

 

[olgranpappy]

That's...somewhat helpful, thanks. But it doesn't help me solve any of my homework questions!

That's nice, because I don't really care about your homework problems.

I wish you good luck, sir.