Slower Than a Turtle – The Speed of Electricity

Slower Than a Turtle – The Speed of Electricity


Hello I’m Daven Hiskey and you are watching
the Today I Found Out Youtube channel. In the video today we’re looking at the surprisingly
slow speed of electricity. Let’s get started. You may be surprised to learn that electrons
flow through a typical copper wire much slower than a turtle walks. Each wire that conducts a flow of electrons,
producing usable electric current, is composed of billions of atoms. To move along it, the
electrons have to traverse these atoms, randomly zig-zagging their way as they do, resulting
in the net flow rate, called “drift velocity,” in a given direction being quite slow. How slow exactly? To calculate it, we use
this formula: I=n*A*v*Q or v=I/(n*A*Q) I is the current, n is the number of electrons
per cubic meter, A is the cross-section of the wire, Q is the charge of an electron and
v is the drift velocity of the electrons. Since the number of electrons in a copper
wire (n) is 8.5 * 10^28 per m^3, and the charge of an electron (Q) is 1.6 * 10^-19 coulombs,
if we also know the cross sectional area and the current, we can calculate the electrons’
drift velocity. For example, suppose you have a current of
14 amps and a copper wire with a cross section of 3 * 10^-6 m^2. Plug in all the numbers
and you get that the electrons are moving at a speed of 3.4 * 10^-4 m/s – or about
a whopping one-third of a millimeter per second. To put it in values that are easier to conceptualize,
this works out to about 1.2 meters or 4.1 feet per hour- a rate about 195 times slower
than the average box turtle, which can cover about 800 feet in that same amount of time. So how is it that something that makes a turtle
look like the Road Runner can more or less instantaneously turn on a light across a room? Chain reaction. The atoms in the wire are crammed together
cheek to jowl, which, while it makes the going slow, also has the electrons more or less
abutting one another. When the switch is turned on, thanks to the electrical potential difference
created by the generator, a force is created to move the electrons, with each pushing its
neighbor, which in turn pushes its neighbor and so on all the way through the wire. So, while no electrons zoom through the wire
to turn on the light as you might have previously thought, it ends up seeming like that is what’s
happening. This is not unlike how when you turn on your faucet, water instantly comes
out despite the fact that your water source might be many miles away.

57 thoughts on “Slower Than a Turtle – The Speed of Electricity

  1. Today I found out that the former presenter is tied up and gagged in a closet just off camera!!!………………….

  2. New Guy is more informative, more detailed, and more focued on the topic. There's also none of the fluff of the "Amazing Things" videos. Oh, and he's better looking than Simon :-).

    But Simon is the engaging one. Youtube is for entertainment, even when it's disguised as education.

  3. You were right until about 1:34. Then you started spouting utter nonsense. Electrical power is transmitted via an electromagnetic wave. The drift velocity of the electrons has nothing to do with it. It's exactly like sound being transported through air with out a wind. PLEASE DON"T MISREPRESENT SCIENCE TO THOUSANDS, POTENTIALLY MILLIONS, OF PEOPLE TAKE YOUR VIDEO DOWN AND FIX IT!!!!

  4. Hi new guy! I'd say we don't bite, but, you've already heard from the peanut gallery below. Simon is not allowed to leave us unsupervised.

  5. Reply with "1" if you want Simon to only host, because there can only be ONE British, dapper, and bald Host. Reply with "2" or greater if you like steak!

  6. C'mon folks – have a heart! Simon had to take a couple of personal days, so Dave very kindly stepped in to help out. Cut the man a little slack – not that he needs any help from me. Support the channel!

  7. Been watching for awhile now, just realized you're a newer channel, very good production content, just shared you guys to my Facebook, hope you grow fast and keep producing quality content!

  8. Since nobody else is saying it, in fact quite the opposite, Thanks so much for filling in for Simon, Dave! I didn't even consider how you guys would balance for the few days while he had to take a surprise week off. People here are just not used to you, but if you had to fill in here regularly or had your own segment, they'd get used to it fast; you're not that bad!
    On a related note, I was surprised by the amount of swearing about this fact in the comments. I didn't think this crowd was so hostile!

  9. And with this very useful and even simple information, that the public is almost never told of some strange reason — at last static electricity and magnetism make some sense for people in general (and everybody who aren't mathematicians and can't read Maxwell's equations). It is amazing to see how useless scientists often are in explaining their theories; often they only explain what, not how.

  10. Dave, you did a good job. I miss your silly, self depricating humor comments this time around. But this was a chill vid. Ingore the entitled nimrods and keep making entertaining, informative vids. btw, you guys should do a Q&A video.

  11. Today I found out I'm an idiot. LOL I got the gist of it though, but I won't be installing wiring any time soon. Well, never.

  12. Intelligent subject and all you "brainiacs" out there can talk about is who presented it??? Did even one of you pay attention to the content?

  13. Do the electrons pull or push? Which ones move first? Do those moving to the positive end move slightly before those coming from the negative of a power supply?

  14. Interesting video, a bit technical for some people with the math, you loose a lot of people with equations – especially long ones like those. However, I like it personally.

  15. I always found the clearest explanation is to think of the electrons in wires as balls in a tube all touching each other. If you push the ball at one end of the tube, the ball at the other end moves almost immediately. It's the transfer of energy that is at near light speed, not the movement of the balls/electrons themselves.

  16. You are doing a fine job sir, pay no attention to the negative comments. Just to show us there are plenty of mean people out there.

  17. I am studying electrical engineering from last four years but no one explain me this thing.it awesome yrr🐒🐯😎 thanks sir!

  18. Now that you know all about the speed of electricity check out this video and find out When a Speed Limit Comes Into Effect:
    https://www.youtube.com/watch?v=tRy8fjND8Qk

  19. Rub your comb on you hair then get it close to a small piece of paper. U will find out that protons do move in the paper resulting in an acceleration of the paper towards the comb. Simple electrostatic experiment! This is what happens in a wire; with a potential difference in the wire, a force is felt by the electrons causing them to accelerate from a high potential to a law one. Think of a stream of electrons being pushed by static electrons on one side, but being pulled by static protons on the other side…

  20. Electrons do not move through conductors. Electricity is conveyed on the outside skin of the wire, through the use of the magnetic and dielectric lines of force. Electrons however are present at the ends of each dielectric force line, and get dragged into the conductor, at a velocity based on the rate of the electric field.

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