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What is Electricity?

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11–20 of 46 posts

Re: What is Electricity?

#11
post #8

Is it possible for signals to propagate as waves, without the electrons moving between atoms? Kind of like in this gif, but without them hopping along? https://cdn.sparkfun.com/assets/9/5/6/1/4/519fcd42ce395f804c...

Yep! These are called plasmons[1]. They are sort of like sound waves for electrons, in that they are compression (i.e. longitudinal) waves.

[1]: https://en.wikipedia.org/wiki/Plasmon

Re: What is Electricity?

#12
My EE professor said to me once:

"Quantum electrodynamics and shit. I'm not a physicist."

I wasn't all that impressed with that answer until many years later after reading Feynman lectures.

Re: What is Electricity?

#13
post #5

I would understand the material better if it were presented as an armadillo analogy. http://smbc-comics.com/index.php?id=3892

Feynman explaining electricity as mentioned https://www.youtube.com/watch?v=kS25vitrZ6g&feature=youtu.be...

Tragically lacking in armadillos though. Maybe he could have got further if he'd included a few.

Re: What is Electricity?

#15
post #9

I've always wondered about the design choice for the shape of batteries. It seems like the shape would indicate the current is flowing the opposite way than it does. Something about the positive terminal just says to me "I'm shooting electrons this way"

It's an historical accident. But electricity as the flow of positive charge is a pretty reliable model outside of materials science and nano-electronics, so why worry?

Re: What is Electricity?

#16

Electricity is being in love. Feynman possibly agrees? http://www.lettersofnote.com/2010/06/you-dont-understand-ord... .

Wow, one of my favorite scientists dissing one of my least favorite. Thanks for the link!

That's quite funny. I see from Wikipedia Feynman was on Wolfram's PhD thesis committee. He can't have been too impressed with Wolframs people skills.

Re: What is Electricity?

#17
post #8

Is it possible for signals to propagate as waves, without the electrons moving between atoms? Kind of like in this gif, but without them hopping along? https://cdn.sparkfun.com/assets/9/5/6/1/4/519fcd42ce395f804c...

Yep! These are called plasmons[1]. They are sort of like sound waves for electrons, in that they are compression (i.e. longitudinal) waves. [1]: https://en.wikipedia.org/wiki/Plasmon

Sweet, thanks. I see in the "possible applications" section of that wikipedia article it is stated that:

"Plasmons are being considered as a means of transmitting information on computer chips, since plasmons can support much higher frequencies (into the 100 THz range, while conventional wires become very lossy in the tens of GHz). However, for plasmon-based electronics to be useful, a plasmon-based amplifier analogous to the transistor, called a plasmonstor, first needs to be created."

So yeah, to all those applied physicists in the audience, hurry up and unleash the plasmonstor! (does anyone really call it that?)

Re: What is Electricity?

#18
post #9

I've always wondered about the design choice for the shape of batteries. It seems like the shape would indicate the current is flowing the opposite way than it does. Something about the positive terminal just says to me "I'm shooting electrons this way"

I got the impression from somewhere that plus and minus was defined long before they could track actual electrons, and thus discover that they had them backwards.

Yes, Benjamin Franklin was the first to assign positive and negative, and got the sign wrong. It looks like it took around another century to figure out that detail.

Re: What is Electricity?

#20

is electricity any different than ionized hydrogen?

Absolutely. To be called "hydrogen" (or any element really), a nucleus must be involved. Electron-free nuclei maintain their elemental identities, they're just positively charged and willing to take on electrons. "Electricity" involves moving electrons, which doesn't always require a nucleus (hence "free electrons")
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