EEVblog > The AmpHour Radio Show

#569 – Electric Fields, Son.

(1/1)

bsfeechannel:
@5:03

--- Quote ---So you have to do transient mode analysis, as us engineers call it, as these physicists don't know about this sort of stuff, you know, this is the domain of engineering [...]

--- End quote ---

 :palm:

Transient analysis was introduced in electromagnetism by Oliver Heaviside, a physicist. He came up with a tool called operational calculus, now supplanted by the related but more rigorous Laplace transform, and what is now known as the Heaviside step function specifically to deal with transients, whose solutions we engineers take for granted, when doing transient analysis.

This is an example of what happens when, in trying to popularize a cool but difficult and unintuitive concept, you have to simplify the theory--otherwise people won't get engaged--and you end up dumbing it down to the point of creating misconceptions.

We, "practical engineers", that were introduced to electronics by magazines or, more modernly, by videos and articles on the internet, get impregnated with these dumbed-down concepts like the water and pipe analogy for electricity flowing in wires. When we are confronted with the real thing and our misconceptions are debunked by the formal theory, we freak out, and these Electroboom-vs-Lewin, "practical engineers"-vs-physicists-like debates ensue.

These disputes will lose their meaning when we realize that physicists and mathematicians created the paradise where we engineers live.

HuronKing:
*Physicists invent transient mode analysis and transmission line theory and apply Poynting theory to invent coax cables.*

"Ya see, physicists don't understand transient mode analysis unlike us manly men practically practical engineers."

I'll go a step farther with your point @bsfeechannel. In the podcast, they discuss various analysis methods, capacitive coupling, transformer model, dipole antenna model etc and say they can all be used to answer Veritasium's riddle... and the Poynting vector is 'physicist blah blah blah.'

When the whole point of Veritasium's video was to try to explain what theory underlies those models in the first place. The answer is of course Maxwell's Theory which smart chaps like Heaviside used to invent coax cables and Hertz used to invent dipole antennas and Tesla used to make induction motors and industrial transformers...

I agree that Veritasium's video wasn't terribly good at making the connection clear. It made a lot of disjointed points and was exceptionally frustrating to mebecause none of it individually was wrong but the connection between the ideas wasn't brought together.

But if the answer to the question he started the video with is "how the heck does energy jump across the air gap in a transformer if energy only flows in wires?" is "so we have a transformer model, don't worry about the energy" then that is also really poor education.

Nikola Tesla, obviously, had an ax to grind against Thomas Edison, but I like this quote

--- Quote ---His [Thomas Edison] method was inefficient in the extreme, for an immense ground had to be covered to get anything at all unless blind chance intervened and, at first, I was almost a sorry witness of his doings, knowing that just a little theory and calculation would have saved him 90 per cent of the labor. But he had a veritable contempt for book learning and mathematical knowledge, trusting himself entirely to his inventor's instinct and practical American sense. In view of this, the truly prodigious amount of his actual accomplishments is little short of a miracle.
--- End quote ---

And I think Tesla was correct. In addition to once having Tesla on his payroll, Edison also hired physicist-engineers:
Charles Steinmetz (discoverer of magnetic hysteresis and inventor of complex phasor analysis and most 'practical' tools we take for granted, seriously, this guy was incredible)
Francis Upton (who has been called the Maxwell to Edison's Faraday, using physics to quantify Edison's experimental observations)
Arthur Kennelly (also a contributor to complex numbers in transient analysis)
John Ambrose Fleming (engineer who was personally instructed by Maxwell and made the equipment for the first transatlantic radio broadcast)

Heaviside also consulted on Edison's work in his publications in The Electrician.

The list goes on.

And I'm really, really doing a terrible injustice to the accomplishments of these accomplished mathematicians and physicists by summarizing them so thusly. My point is that Tesla is correct. Edison with his 'practical' mind didn't know jackshit about how any of the inventions produced in his lab actually worked. He had an army of incredible physicists to explain how any of it worked and they were all masters of Maxwell's theory. And they all utterly changed our world.

"Physicists vs engineers" is a crock that needs to stop. I teach my electrical engineering courses as applied physics. We ought to be as smart, if not smarter, than the physicists because we must construct the apparatus described by the theories and know when simplifications are appropriate and when they are not.


PS
Fleming discovered the Right-Hand Rule (for generators):
https://en.wikipedia.org/wiki/Fleming%27s_right-hand_rule#:~:text=Fleming's%20right%2Dhand%20rule%20(for,moves%20in%20a%20magnetic%20field.&text=The%20thumb%20is%20pointed%20in,direction%20of%20the%20magnetic%20field.

nfmax:
For more on the development of EM wave engineering theory from its roots in Maxwell's original work, and especially on the people involved, read Bruce J Hunt, The Maxwellians published by Cornell University Press (ISBN 978-0-8014-8234-2)  8)

bsfeechannel:

--- Quote from: HuronKing on February 07, 2022, 04:30:55 pm ---"Physicists vs engineers" is a crock that needs to stop.

--- End quote ---

It's interesting how Dave tries to coopt Chris, who is dismissive, to his cause against physicists.


--- Quote ---Dave: Which side of the fence do you sit on? [...] No fence sitting.
Chris: [...] I usually dig under the fence and don't pay attention.
Dave: [speechless]
Chris: I mean, does it really matter, if I can turn my blender on at the end of the day?
Dave: It matters because you're a design engineer and an influencer.

--- End quote ---

Don't get me wrong, I'm a big fan of Dave's for this forum and his channel, but sometimes I get disappointed for some of his positions (which of course he's entitled to), like this one for example.

In all my years of engineering I've never seen a movement against science, physicists or the academia in general. I think that the role of an "influencer" should include the dismissal of such misconceptions, but what we have seen is that many "influencers" start to believe their own publicity and, since popularity is power, they perceive the debunking of their misconceptions as a threat to their credibility.

There's no physcists vs engineer. There's influencers vs physicists/engineers who point out their (influencer's) cherished misconceptions.

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