Mermin is probably the source of the phrase - his April 1989 Physics Today essay cited in the link above. It gets misattributed to Feynman. If he picked it up from somewhere else, no one has been able to demonstrate that.
"Fields guide energy, and the energy does the actual work on the charges."
We know the fields are there BECAUSE of their effects on energy?
I'm trying to imagine a scenario in which you could detect fields if they didn't change the flow of energy in some manner. Energy has to be expended for work to be done. In this context expended effectively means distributed from a previously concentrated state? Transformed to kinetic energy, heat losses, and radiated away, etc.
The energy creates the fields? Or induces the fields in some way? And then the fields guide the energy?
I mention this because it is eerily reminiscent of the paraphrase of Einstein: "Mass bends Space and Space tells Mass how to move."
Off the top of my head analogy, but consider the topology of a hilly park as tracing out the gravitational potential of the region. A mass moves along the hills and its motion is subject to gravitational fields/forces relative to the location of the mass in the park. The strength and direction of the net force, the instantaneous velocity, and acceleration on the mass will be dependent upon the location of the mass relative to the potential and its gradient.
Space and time are "bent" in this case due to the inability of the mass to pass into the ground, but it is a kind of bending the gravitational topology into the shape the mass "sees".
You can map an electric potential based on charge configurations in a quasi-static system and produce a similar set of hills and valleys that the charges might roll into or out of that allows you to describe their motion.
The EM force is taken to be moderated by the exchange of photons--our energy packets.
There seems to be a verb missing in this quote, at the point where I have inserted a bracketed ellipsys:
"NO PART of the writings of Franklin exhibits his sagacity and his power of scientific generalization in a more conspicuous light than his theory of electricity. The talent to discover isolated facts in any branch of science although possessed by a few is comparatively inferior to that characteristic of mind which ( ... ) to the invention of an hypothesis embracing in a few simple propositions whole classes of complete phenomena [[v]]."
LEADS to?
LENDS ITSELF to?
Something of that sort seems to be indicated but since I don't have the referenced material I cannot say if it was missing in the original or has been lost in transcription.
It's not important to the article, I'm just trying to make sense of it and it defies me.
This was one of the best serials on substack. Thank you for sharing your ideas so freely.
I immensely enjoy the contrasting symmetry and their profound consequences:
Electric energy - Magnetic energy = 0
Kinetic energy (space^2) - Potential energy (time^2) = 1
No diss on Feynman, but if QED is determined to be less than the crown jewel of physics, “shut up and calculate” is gonna be a really lousy epitaph.
I'm told Feynman said "Shut up and calculate," but I've only been able to find it expressed by David Mermin in print. https://pubs.aip.org/physicstoday/article/57/5/10/412592/Could-Feynman-Have-Said-This
The difficulty is not the sourcing as much as everyone tags the line to him. If he didn't say it, then the source is needed to clear his name.
Mermin is probably the source of the phrase - his April 1989 Physics Today essay cited in the link above. It gets misattributed to Feynman. If he picked it up from somewhere else, no one has been able to demonstrate that.
"Fields guide energy, and the energy does the actual work on the charges."
We know the fields are there BECAUSE of their effects on energy?
I'm trying to imagine a scenario in which you could detect fields if they didn't change the flow of energy in some manner. Energy has to be expended for work to be done. In this context expended effectively means distributed from a previously concentrated state? Transformed to kinetic energy, heat losses, and radiated away, etc.
The energy creates the fields? Or induces the fields in some way? And then the fields guide the energy?
I mention this because it is eerily reminiscent of the paraphrase of Einstein: "Mass bends Space and Space tells Mass how to move."
Off the top of my head analogy, but consider the topology of a hilly park as tracing out the gravitational potential of the region. A mass moves along the hills and its motion is subject to gravitational fields/forces relative to the location of the mass in the park. The strength and direction of the net force, the instantaneous velocity, and acceleration on the mass will be dependent upon the location of the mass relative to the potential and its gradient.
Space and time are "bent" in this case due to the inability of the mass to pass into the ground, but it is a kind of bending the gravitational topology into the shape the mass "sees".
You can map an electric potential based on charge configurations in a quasi-static system and produce a similar set of hills and valleys that the charges might roll into or out of that allows you to describe their motion.
The EM force is taken to be moderated by the exchange of photons--our energy packets.
There seems to be a verb missing in this quote, at the point where I have inserted a bracketed ellipsys:
"NO PART of the writings of Franklin exhibits his sagacity and his power of scientific generalization in a more conspicuous light than his theory of electricity. The talent to discover isolated facts in any branch of science although possessed by a few is comparatively inferior to that characteristic of mind which ( ... ) to the invention of an hypothesis embracing in a few simple propositions whole classes of complete phenomena [[v]]."
LEADS to?
LENDS ITSELF to?
Something of that sort seems to be indicated but since I don't have the referenced material I cannot say if it was missing in the original or has been lost in transcription.
It's not important to the article, I'm just trying to make sense of it and it defies me.
“leads” And the reference was wrong, too. I’ve fixed it. Thanks!
Good catch.
I have to pay close attention because I’m over my head in much of this topic.