harrylin said:
Surely many people do! It's fascinating to see how the electrostatic force of a plastic pen can deflect "at a distance" the water flow from a tap and as a kid I wondered what "is there" that transmits magnetic force, as we can feel how repulsive forces interact at a distance.
Oh, I'm fascinated by it. I'm saying that, especially in THIS thread, this issue NEVER came up. And I've seen many other threads where people dived in right into the more complex situation without bothering to step back and see if they've understood the simpler case.
This was also asked by the interviewer in the linked video - and I find Feynman's reply disappointing. In the middle he admitted that he didn't know the answer which is fine, but mostly he was just looking for excuses: he spent much time explaining how difficult it is to answer a "why" question and he pretended that no explanation is possible using concepts with which the interviewer is familiar.
This "incident" is well-documented, even by the interviewer. Still, at some point, I can understand Feynman's frustration, keeping in mind that this was the SAME guy that captivated the media and the public with his very simple demonstration during the Challenger disaster hearing.
As Einstein was known to say, explain it in simple terms, but not any simpler. One runs the risk to making inaccurate analogies when one tries to do many of these things at the pedestrian level.
nikolafmf said:
Yeah, that is a good question which could solve many dilemmas. What exact gets transmitted...? And if it is photons, how they make charges to feel force?
This gives me the opportunity to kill 2 birds with one stone.
1. It is imperative that, in learning, one starts with the simpler, more basic understanding. This is why I puzzled at the question, because it seems to start with the more complicated time-varying problem of something oscillating. When we teach physics to students, we try to start with something simpler, just so they get an idea and a feel for the physics, before proceeding to more complex physics and situations. That's how one HAS to learn. Really, the cliche that one has to learn how to walk FIRST before attempting to run truly applies here!
2. Many people, especially crackpots, have accused physicists of wanting to stick "within the box", and that we are unwilling to work "outside the box". This is, obviously, utterly false. What happens usually is that we often discover that what we consider to be a "rule" turns out to be only true for a limiting case. For example, we thought we have a conservation rule for energy, and a separate conservation rule for mass. Of course, we KNOW know that the more UNIVERSAL rule is the conservation of mass(energy content)+energy. So we change our concept when that has been shown convincingly to be valid.
Now that last argument applies here with respect to the CLASSICAL FIELD (since this is posted in the Classical Physics forum). We originally thought that all waves must have a medium to propagate in. When Special Relativity came out, and upon further development and experimentation throughout the previous century, we realize that the concept of a medium for EM radiation is superfluous. It is not needed, and more importantly, it is not detected! So we drop the "universal" requirement that all waves must have a medium to propagate. Thus, Maxwell equations, the equations that describe classical EM interactions, no longer require one!
So now, instead of physicists being stuck to thinking only within the box, it now appears that the general public/laymen are the ones who can't go beyond this box. Why? Because it doesn't make sense, or conceptually difficult to accept? That isn't a very strong argument (it isn't a very weak argument either), because having something to "make sense" or conceptually acceptable requires that one is FAMILIAR and understand that something. There are many things that don't make sense but are true, simply because we did not understand it in the beginning.
So the question on "what is waving" cannot be answered other than saying "nothing". This is because asking "what is waving" assume that there's something out there that is waving, and you want to know what it is (other than, presumably, the electric and magnetic fields). One can't answer that question anymore than one can answer "So, when did you stop beating your wife?" Both made an a priori assumption that hasn't been verified.
If you ask "Does EM require a medium to propagate?", then the answer is NO. Once that is established, then the question on what is "waving" doesn't come up anymore, because it becomes moot!
Note that we haven't dealt with quantum field theory, or in particular, quantum electrodynamics. I am extremely hesitant to want to start delving into that, because I can see myself having to take steps backwards at every step along the way to explain the explanation.
I don't know if my response here is sufficient to satisfy the conceptual understanding of this. It may not be satisfying to hear that "nothing" is the answer. However, Mother Nature has no obligation to cater to our feelings or our needs. She does what she does.
Zz.
