How long does it take an electron to travel from NY to LA through a copper wire?

[cthulu2016]

Last edited Fri Jun 22, 2012, 05:04 PM - Edit history (1)

(Direct current)

If you answered "less than a second" (at the speed of light) give yourself 1/10th credit. It's an sensible-seeming answer, which counts for something.

If you answered something appreciably slower than the speed of light, in hours or days, give yourself 1/2 credit.

If you said, "About a month... probably 2 to 6 weeks depending on conditions" give yourself full credit.

The weird world of science. When we use electric power it isn't like a stream of electrons going from the power plant to our house. It's more like the power plant is sending a field (which does propagate at the speed of light) ordering electrons already in the wire, or already at our end, to do their thing.

(It could be worse. Speed of light photons from the center of the sun take thousands of years to get to the surface.)

_______________________

Since I have recently posted about Samuel Morse (who did not invent the telegraph, but had enough money to end up with the patent), and Edison's first invention (a legislative vote counting machine), and now about how long it would take an electron to navigate through collisions with an incredibly large number of copper atoms, the reader may properly deduce that my current audio book in my car is about the history of man's study and use of electricity. I prefer non-fiction in the car because it is usually broken into 10 or 20 minutes bits of listening time. I find fiction is better at home, or on a long trip.

Also, I post things like this because the informative replies are always a learning experience for me, and I assume for others. All I know is what I read in the papers.

[dimbear]

1. What if the wire leads the the lights of a 747? n/t

[jberryhill]

2. Another way of looking at it...

If you have a long hose already full of water, the water comes out of the end of it when you turn the tap on, which is a lot sooner than water from the tap travels through the hose.

Or.... A crowd can send a wave around a stadium faster than any member can run around it. Indeed, nobody doing the wave goes anyhwhere.

[Wait Wut]

3. I didn't need to know this.

But, somehow, I'm intrigued. My science poor brain is picturing little electrons running really, really fast through a tunnel that looks copperish. They all have angry looks on their little faces and resemble PacMan with a helmut.

Oh...and they're humming in some sort of weird marching tune.

It's been a long week. I have only a few braincells left and they aren't my brightest ones.

[cthulu2016]

7. Ah... but you see, if that were the case

the electrons would be pouring out of your wall sockets all day long. They would be like an open water tap. Soon you'd be knee-deep in electrons (and every day would be a very bad hair day)

I am with you, by the way. I am fine with not being able to visualize the probability waves of sub-atomic interactions and such, but one expects everyday thing like electricity to be less mystical.

[unblock]

4. depends on if tsa selects it for a subatomic strip-search.

and the correct answer is "depends on how fast the copper wire is moving".

[randome]

5. A Republican copper wire or a Democratic one?

[Uncle Joe]

6. Two atoms are in a bar. One says "I think I lost an electron"

Last edited Sat Jun 23, 2012, 12:35 PM - Edit history (1)

The other says "Are you sure" to which the other replies, "I'm positive."

Wadsworth

Thanks for the thread, cthulu.

[Brother Buzz]

8. AC or DC current? Soild or stranded copper wire?

[Rex]

9. Well what do you expect with a layover in Dallas?

nt.

[FarCenter]

10. It depends on the voltage; if it's AC voltage they never go anywhere.

They just shift back and forth.

If DC, see Drift Velocity http://en.wikipedia.org/wiki/Drift_velocity

[cthulu2016]

12. Thanks. DC.

[slackmaster]

11. Yep, current is the flow of electrical potential, not of electrons per se

In fact current by convention goes the opposite direction of electrons.

[hunter]

18. Thank you, Benjamin Franklin...

He had a fifty-fifty chance.

http://en.wikipedia.org/wiki/Electric_charge#History

But it's satisfying in a ying-yang sort of way. Electrons going one way, current the other...

Would the modern world have been any different if Franklin had called it so electrons came out with a "positive" charge?

[razorman]

13. 1/1069th of a second. 17 hours if it has to go through Cleveland. :)

[Scootaloo]

14. This is kind of basic physics, isn't it?

Is it just me? Meh. I guess with the state of science education in the US...

[cthulu2016]

17. Well, yes. It is.

And a lot of things I post are, to me, excruciatingly basic law and elementary politics and obvious constitutional theory.

But they are often interesting to someone else.

If all posts were limited to, "Only post things no other person on DU knows," it wouldn't a very useful discussion board. (Though quite abstruse, since different people here know a lot of things.)

[hunter]

15. You can't tag electrons like an ornithologist tags birds, so we can't really know.

Electrons are particles that cannot be distinguished from one another, even in principle.

Explanations like yours obscure the weird behaviors of things like electrons or photons. The electrons and the "field" of your description are in essence a single entity. The fixed molecules of a conductor will behave a certain way under the influence of an electric current, but there's no way of picking individual electrons from the crowd, no way of telling when or if a particular electron has entered or exited the power line. A power plant is not analogous to a water pump, and electrons are not analogous to molecules of water.

In his Nobel Lecture December 11, 1965 Richard Feynman recalls the "one electron universe" thought experiment of physicist John Wheeler:

I received a telephone call one day at the graduate college at Princeton from Professor Wheeler, in which he said, "Feynman, I know why all electrons have the same charge and the same mass." "Why?" "Because, they are all the same electron!" And, then he explained on the telephone, "suppose that the world lines which we were ordinarily considering before in time and space - instead of only going up in time were a tremendous knot, and then, when we cut through the knot, by the plane corresponding to a fixed time, we would see many, many world lines and that would represent many electrons, except for one thing. If in one section this is an ordinary electron world line, in the section in which it reversed itself and is coming back from the future we have the wrong sign to the proper time - to the proper four velocities - and that's equivalent to changing the sign of the charge, and, therefore, that part of a path would act like a positron."

http://en.wikipedia.org/wiki/One-electron_universe

http://en.wikipedia.org/wiki/John_Archibald_Wheeler

[PoliticAverse]

16. Most likely the electron will be waiting forever...

as the paths are now fiber optic.

[GeorgeGist]

19. Where do they stay ...

once they get to LA?

[hootinholler]

20. Battery Park?

I'm not sure if LA has a Battery Park, but many big cities do.

[hootinholler]

21. They never get there!

If the current is AC, then the electrons oscillate on the wire never moving more than a few feet.

If the current is DC, then the wire resistance means that the voltage would have to be so high and the wire so thick (even stranded) as to make it very difficult and expensive to set the experiment up, so much so that it would nearly be impossible. Line loss is why we use AC to transmit power.