I Quantum fields and "mediator" particles

[Rick16]

[Moderator's note: Spin off from another thread due to topic/forum change.]

I have this uneasiness about mediator particles in general. On the one hand, nature is so economical, even austere (shortest path, shortest time, Fermat's principle, least action, the lazy universe and all that), and on the other hand there is this boundless wastefulness with particles, as if somebody else paid for them. How can I conceptually reconcile these extremes?

 

[Demystifier]

What do you mean by "boundless wastefulness with particles"?

 

[PeroK]

[Moderator's note: Spin off from another thread due to topic/forum change.]

I have this uneasiness about mediator particles in general. On the one hand, nature is so economical, even austere (shortest path, shortest time, Fermat's principle, least action, the lazy universe and all that), and on the other hand there is this boundless wastefulness with particles, as if somebody else paid for them. How can I conceptually reconcile these extremes?

What about learning some real phyiscs?

 

[Rick16]

Okay, this was not a question that I wanted to use to start a thread. It was just a side note in another thread.

 

[PeterDonis]

Okay, this was not a question that I wanted to use to start a thread. It was just a side note in another thread.

It was a topic change from the previous thread; that's why it got spun off. Answering it in the other thread would have been a thread hijack. It would even have been a forum hijack, since the question doesn't belong in the BTSM forum; it falls well within standard QFT in the regime where it has been experimentally tested.

If you don't want answers to the question, you should not have asked it at all.

 

[PeterDonis]

On the one hand, nature is so economical, even austere (shortest path, shortest time, Fermat's principle, least action, the lazy universe and all that)

All this is just an approximation in the classical limit.

on the other hand there is this boundless wastefulness with particles

I'm not sure what you mean by that. If you are thinking about "virtual particles" in QFT, be advised that that concept has serious limitations, and certainly doesn't justify any claim of "boundless wastefulness:". You might want to read this Insights article:

https://www.physicsforums.com/insights/misconceptions-virtual-particles/

How can I conceptually reconcile these extremes?

By fixing your conceptual scheme. In a correct conceptual scheme, there is nothing that needs to be reconciled.

 

[Nugatory]

there is this boundless wastefulness with particles,

The word "particle", as it used in quantum mechanics and especially quantum field theory, means something different than you would assume from the normal use of the word. A quantum particle is not a tiny little object that in large numbers makes up the field the way water molecules in large numbers make up a cup of water.

Thus the apparent proliferation is more an artifact of the mathematical description we use to describe fields than the proliferation of any real objects. As an analogy, I can write the sound wave coming out of an orchestra as the sum (superposition, in the language of QM) of a very large number of sine waves each with with its own frequency... but we would not think that nature was being wasteful with frequencies just because I need a lot of them to write the wave as sum of frequencies.

There's no really layman-friendly explanation of what a quantum particle is and how they emerge from the mathematical description of a field. The closest I know of is this link, which explains in passing how an electromagnetic field can be written as a sum of single-photon states.

 

[Rick16]

The word "particle", as it used in quantum mechanics and especially quantum field theory, means something different than you would assume from the normal use of the word. A quantum particle is not a tiny little object that in large numbers makes up the field the way water molecules in large numbers make up a cup of water.

Thus the apparent proliferation is more an artifact of the mathematical description we use to describe fields than the proliferation of any real objects. As an analogy, I can write the sound wave coming out of an orchestra as the sum (superposition, in the language of QM) of a very large number of sine waves each with with its own frequency... but we would not think that nature was being wasteful with frequencies just because I need a lot of them to write the wave as sum of frequencies.

There's no really layman-friendly explanation of what a quantum particle is and how they emerge from the mathematical description of a field. The closest I know of is this link, which explains in passing how an electromagnetic field can be written as a sum of single-photon states.

Thank you. This is the kind of answer that I was hoping to get.