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Why is Maxwell's theory so hard to understand? (2007) [pdf]

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Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#21

Post by ncmncm »

It is unfortunate that Dyson neglects the role of Oliver Heaviside, again. This is in a long tradition of English neglect, ultimately traceable to Heaviside's status as a commoner. Heaviside invented the mathematical tools we still use to understand and teach Maxwell, and most of the important consequences of the theory, but Pupin, Hertz, Marconi, and deForest used his methods and took got the credit.

Today Heaviside's method is taught as Laplace transforms, with Heaviside's name scrubbed off. We only hear of him as an alternative name for the step function, the integral of the Dirac impulse function, and of the "Heaviside layer", the ionosphere that makes transcontinental radio actually possible, but we would have waited decades longer without him.

An excellent reference for the importance of Heaviside in the ultimate success of application if Maxwell's theory is Paul J. Nahin, "Oliver Heaviside: The Life, Work, and Times of an Electrical Genius of the Victorian Age", https://www.amazon.com/Oliver-Heaviside-Electrical-Genius-Vi...

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#22

Post by whatshisface »

NotAnEconomist wrote: post #20
bsder wrote: post #18

People didn't really get Maxwell because Maxwell's equations don't need a medium aka "aether". Waves propagating without a medium is a shocking message in this time frame. Maxwell published his equations in 1861/1862 in first form. In 1887, the Michelson–Morley experiment gave the first experimental disproof of the "aether". It also doesn't help that you have things like "displacement current" and have to find strang…

> In 1887, the Michelson–Morley experiment gave the first experimental disproof of the "aether". In what way is LIGO not a bigger, and successful, version of the Michelson-Morley experiment? I'm honestly asking, because from my limited understanding, it seems to be. From Wiki: > This result is generally considered to be the first strong evidence against the then-prevalent aether theory, and initiated a line of resear…

There might be some philosophical or creative writing overlap in the way the two are described, but the actual things that the theories are saying are completely different, lacking even a conceptual similarity.

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#24

Post by bsder »

NotAnEconomist wrote: post #20
bsder wrote: post #18

People didn't really get Maxwell because Maxwell's equations don't need a medium aka "aether". Waves propagating without a medium is a shocking message in this time frame. Maxwell published his equations in 1861/1862 in first form. In 1887, the Michelson–Morley experiment gave the first experimental disproof of the "aether". It also doesn't help that you have things like "displacement current" and have to find strang…

> In 1887, the Michelson–Morley experiment gave the first experimental disproof of the "aether". In what way is LIGO not a bigger, and successful, version of the Michelson-Morley experiment? I'm honestly asking, because from my limited understanding, it seems to be. From Wiki: > This result is generally considered to be the first strong evidence against the then-prevalent aether theory, and initiated a line of resear…

If LIGO confirmed "aether", then the measurements in the perpendicular arms would vary depending upon time (orientation of Earth in rotation, orientation of Earth around Sun, etc.).

As far as I know, they very much do NOT vary--to an absolutely amazing precision.

As far as I can tell, if the "aether" existed and we could detect it, we basically would have no hope of detecting gravitational waves.

> Naively, spacetime and quantum fields are both forms of aether theories.

Not ... really.

The existence of "aether" implies a preferential frame of reference. And every experiment we have done to attempt to establish such has failed.

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#25

Post by ncmncm »

k9s9 wrote: post #2

Interesting. And makes me wonder what else we are missing and misunderstanding, as we waste so much time trying to express the complexity of the world in spoken language rather than math. Not just physics but in sociology, psychology, economics etc. Faraday purely from experiments 30-40 years before Maxwell, intuitively understood electromagnetism. Nobody serious believed it because he didn't have the training to exp…

[retracted]

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#26

Post by tntn »

ncmncm wrote: post #21

It is unfortunate that Dyson neglects the role of Oliver Heaviside, again. This is in a long tradition of English neglect, ultimately traceable to Heaviside's status as a commoner. Heaviside invented the mathematical tools we still use to understand and teach Maxwell, and most of the important consequences of the theory, but Pupin, Hertz, Marconi, and deForest used his methods and took got the credit. Today Heaviside…

I'll second that book recommendation.

It's incredible that you can ask a graduating class of EEs if they know of heaviside and only get some mumbling about a step function, given that Heaviside developed the majority of the fundamental ideas still used in EE. Complex impedance, vector calculus, Maxwell's equations, telegrapher's equations, precursors of s-domain methods, inductive loading, many of the names for AC circuit concepts.

I think Hertz acknowledged Heaviside's contributions, though, and didn't intentionally take credit for his work. I could be confused, though.

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#27

Post by ncmncm »

tim333 wrote: post #19
k9s9 wrote: post #2

Interesting. And makes me wonder what else we are missing and misunderstanding, as we waste so much time trying to express the complexity of the world in spoken language rather than math. Not just physics but in sociology, psychology, economics etc. Faraday purely from experiments 30-40 years before Maxwell, intuitively understood electromagnetism. Nobody serious believed it because he didn't have the training to exp…

Spoken language has a lot going for it. I note the featured article and it's discussion are all words not maths. By the way looking at Maxwell's paper it seems awful complicated https://royalsocietypublishing.org/doi/pdf/10.1098/rstl.1865... compared to the modern form of the equations https://ethw.org/w/images/d/d6/Maxwell_image_02.jpg

The modern form of the equations was worked out by commoners, so had to be filtered through the work of others before it could be taught.

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#28

Post by ncmncm »

tntn wrote: post #26
ncmncm wrote: post #21

It is unfortunate that Dyson neglects the role of Oliver Heaviside, again. This is in a long tradition of English neglect, ultimately traceable to Heaviside's status as a commoner. Heaviside invented the mathematical tools we still use to understand and teach Maxwell, and most of the important consequences of the theory, but Pupin, Hertz, Marconi, and deForest used his methods and took got the credit. Today Heaviside…

I'll second that book recommendation. It's incredible that you can ask a graduating class of EEs if they know of heaviside and only get some mumbling about a step function, given that Heaviside developed the majority of the fundamental ideas still used in EE. Complex impedance, vector calculus, Maxwell's equations, telegrapher's equations, precursors of s-domain methods, inductive loading, many of the names for AC ci…

It was deForest, particularly, who pretended to originality. I should have written "got".

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#29

Post by NotAnEconomist »

bsder wrote: post #24
NotAnEconomist wrote: post #20

Earlier quoted context omitted.

> In 1887, the Michelson–Morley experiment gave the first experimental disproof of the "aether". In what way is LIGO not a bigger, and successful, version of the Michelson-Morley experiment? I'm honestly asking, because from my limited understanding, it seems to be. From Wiki: > This result is generally considered to be the first strong evidence against the then-prevalent aether theory, and initiated a line of resear…

If LIGO confirmed "aether", then the measurements in the perpendicular arms would vary depending upon time (orientation of Earth in rotation, orientation of Earth around Sun, etc.). As far as I know, they very much do NOT vary--to an absolutely amazing precision. As far as I can tell, if the "aether" existed and we could detect it, we basically would have no hope of detecting gravitational waves. > Naively, spacetime…

But the arms are predicted to vary in those cases by the same theory that LIGO is confirming: our rotation causes frame dragging, and there's some weird Sun-Earth orbital relativistic effects as well, right?

I know the Sun-Jupiter orbit produces a large portion of the estimated 5,000 watts of gravitational emissions given off by our solar system. My mental model of this is that it perturbs the aether ("spacetime") through which it travels, radiating waves which carry energy out of the system. Is there a different one?

It's just the power output in those waves is incredibly, incredibly low -- LIGO can only hear much larger events, such as large astral bodies colliding.

So I'm not sure I understand -- there seems to be at least a gravitational aether.

Re: Why is Maxwell's theory so hard to understand? (2007) [pdf]

#30

Post by grigjd3 »

k9s9 wrote: post #2

Interesting. And makes me wonder what else we are missing and misunderstanding, as we waste so much time trying to express the complexity of the world in spoken language rather than math. Not just physics but in sociology, psychology, economics etc. Faraday purely from experiments 30-40 years before Maxwell, intuitively understood electromagnetism. Nobody serious believed it because he didn't have the training to exp…

In truth, it generally takes significant time to arrive at fundamental theories. Most people don't realize this because in a physics class, at best, you might get taught when so-and-so published an equation.
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