
What is Electricity? - SunSparc
https://learn.sparkfun.com/tutorials/what-is-electricity
======
dspillett
Electricity is a myth.

Everything is really run by blue smoke and your cables are tubes to move it
around. The wire inside the cable is just for strength.

You can see this is true when something shorts. The resulting hole in the
system allows some blue smoke to escape, and the machine then stops working.

~~~
andars
Everything goes downhill once you see the magic smoke come out of an IC.

------
murbard2
I would understand the material better if it were presented as an armadillo
analogy. [http://smbc-comics.com/index.php?id=3892](http://smbc-
comics.com/index.php?id=3892)

~~~
tim333
Feynman explaining electricity as mentioned
[https://www.youtube.com/watch?v=kS25vitrZ6g&feature=youtu.be...](https://www.youtube.com/watch?v=kS25vitrZ6g&feature=youtu.be&t=8m17s)

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

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erehweb
There is a story (perhaps apocryphal) that a student at Cambridge [?] was
asked this at an exam many years ago.

He said "I'm sorry, I did use to know, but I've forgotten".

"How very unfortunate," said the professor. "In all of history, only two
people have known what electricity is. One the creator, and the other
yourself. And now one of the two has forgotten."

~~~
SunSparc
Haha, I daresay that student did poorly on the exam.

------
jimmahoney
I like Dave Barry's explanation of electricity (e.g.
[http://www.comp.leeds.ac.uk/Perl/Misc/electricity.txt](http://www.comp.leeds.ac.uk/Perl/Misc/electricity.txt)
) including

"the electric company sends electricity through a wire to a customer, then
immediately gets the electricity back through another wire, then (this is the
brilliant part) sends it right back to the customer again. This means that an
electric company can sell a customer the same batch of electricity thousands
of times a day and never get caught, since very few customers take the time to
examine their electricity closely. In fact, the last year any new electricity
was generated was 1937."

and

"AMAZING ELECTRONIC FACT: If you scuffed your feet long enough without
touching anything, you would build up so many electrons that your finger would
explode! But this is nothing to worry about unless you have carpeting."

~~~
noonespecial
Its actually worse than that. You keep the same electrons, the electric
company just wiggles them back and forth and then bills you for it.

As my prof used to say about AC, "you don't pay for the swing, you pay for the
push".

------
mrow84
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...](https://cdn.sparkfun.com/assets/9/5/6/1/4/519fcd42ce395f804c000000.gif)

~~~
johncolanduoni
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](https://en.wikipedia.org/wiki/Plasmon)

~~~
mrow84
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?)

------
shostack
Bit of a tangent, but reading this was really interesting in the context of
the book I'm reading now, "Ra."[1]

It takes place in a modern day world where "magic" was discovered decades ago
and is now a formal science with graduate programs right up there with
engineering and physics. It has rules, and in fact one character just created
a magical quine (which was apparently thought to be impossible).

If every sufficiently advanced technology is indistinguishable from magic, I
wonder what the turning point was when people stopped thinking of electricity
as magic and instead thought of it as science.

When you get into talk about electrons, how they flow, how they transfer
between atoms, and how we end up harnessing them, it is very easy for the D&D
nerd in me to mentally replace "electrons" with "mana".

Absolutely fascinating world we live in.

[1] [http://qntm.org/ra](http://qntm.org/ra)

~~~
SunSparc
So true. If the Egyptians could see what we play with every day, they would be
amazed. I imagine there is quite a bit of shock for people in deep
jungle/desert tribes that still live in huts when they are introduced to
"modern" technology. Magic is probably the best way for them to explain it
initially. Of course, "magic", usually just means, "something I do not
understand".

~~~
ajross
Yeah, but that's driven by familiarity not understanding. A median western
marketing executive has no better understanding of electrodynamics than your
amazonian tribeswoman, yet isn't surprised by the radio in his phone.

~~~
sebkomianos
Maybe it's also worth clarifying that familiarity doesn't mean or lead to
understanding. Sometimes quite the opposite (hint hint: newer generation using
smartphones, social networks, etc without understanding them at all and then
some from older generations remarking how they can be dangerous and
upsetting).

------
0xdeadbeefbabe
Electricity is being in love. Feynman possibly agrees?
[http://www.lettersofnote.com/2010/06/you-dont-understand-
ord...](http://www.lettersofnote.com/2010/06/you-dont-understand-ordinary-
people.html).

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

~~~
tim333
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.

~~~
snaky
That skills are legendary
[https://www.reddit.com/r/programming/comments/8l3bq/wolfram_...](https://www.reddit.com/r/programming/comments/8l3bq/wolfram_and_lisp/)

------
togusa
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.

------
heatish
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"

~~~
digi_owl
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.

~~~
hga
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.

~~~
0942v8653
[https://xkcd.com/567/](https://xkcd.com/567/)

------
SunSparc
Great little intro to electricity. SparkFun has some good educational
tutorials.

------
LgWoodenBadger
is electricity any different than ionized hydrogen?

~~~
delinka
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")

~~~
LgWoodenBadger
Ok, but hydrogen's nucleus is only a proton...

------
powertower
> A negative charge has an inward electric field because it attracts positive
> charges. The positive charge has an outward electric field, pushing away
> like charges.

If this was true, then why does a negative charge not attract other negative
charges?

~~~
aaronkrolik
Electric field forces are drawn as if you were placing a small positive charge
in the field. The wording is awkward. If convention used a small negative test
charge, the language (and diagram arrows) would be flipped. "inward electric
field" is only with respect to a positive charge, not to all charges.

------
emcrazyone
Couldn't read much past the statement:

"Electricity is briefly defined as the flow of electric charge, but there’s so
much behind that simple statement"

Electricity is the force not the flow. The flow is the current. The term,
"Electricity" in every college course I had on it in getting my degrees is
always the EMF (Electromotive Force).

Sorry to nit pick but I just have a real problem when articles are written
from sense of authority (An electronics company) and don't get the details
correct. It can kick off a cycle of incorrect learning and confusion if you're
relatively new and getting into electronics.

~~~
etep
I disagree with the nitpick. Electricity is not a technical term. In its
common usage, it encompasses many effects and broadly invokes many technical
concepts, i.e. among them EMF or voltage, current, electromagnetic waves, etc.
etc.

This article is not written for physicists, engineers, or anyone else so
technically trained. If it were, it would read as follows: "Electricity is a
vague term used to variously refer to the many aspects of electromagnetic
phenomena."

If you want to keep that sentence, and cover your bases, you could reword as
"the flow of electric charge, the potential to cause the same." And in any
case, the escape clause already exists as "there’s so much behind that simple
statement."

~~~
emcrazyone
What proof do you have the article wasn't written for physicists, engineers or
anyone else so technically trained?

This is the basis for not agreeing? If it is, then it seems you drew an
assumption then formed an opinon that is contrary to many college level
courses, texts, and teachings I've sat through where electricity is carefully
described as the force alone.

~~~
cbd1984
> What proof do you have the article wasn't written for physicists, engineers
> or anyone else so technically trained?

It's defining the term 'electricity', for a start.

