# 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. Akshat Shah says:

Hi new narrator!!!

2. Charlie Lindler says:

Not gonna lie, you look and sound like you are reading off a script in front of you.

3. cloverfield911 says:

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

4. TRENDY says:

I don't like him. He sounds bored, nervous and unengaging

5. TheDajamster says:

Tell that to anyone who's ever hit a power line while digging a hole.

6. Martin Macedonian says:

cloverfield911 cracked me up with your comment 😀

7. Eise says:

I feel like an introduction should have been done. Is this going to be a regular thing?

8. TruckerJDub says:

I hope this guy was a one time thing.

9. Elizabeth says:

But.. where is Simon? 🙁

10. Stefan Travis says:

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.

11. ernie pokemon says:

who the FUCK are you David?

12. Josiah Luscher says:

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!!!!

13. Viki Banaszak says:

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.

All hail new guy! New guy, new guy!

15. BobEckert56 says:

Simon? What's up?

16. Trav2016 says:

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!

17. flanker says:

What happened to the bald fuck? This guy isn't bad but the way he speaks makes me sleepy.

18. Mike Oz says:

British accent = more interesting. This guys like a robot

19. Sarah says:

where is my Simon?!

20. ‘Murica 1776 says:

What the actual fuck did you just say

21. Aaron Rice says:

Uuugghhh….nerds.

22. Yeison Garces says:

Where's Simon?

23. matt THORNE says:

He's the co-founder and he's just covering videos now and then to help with the work load.

24. Corky Schillinger says:

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!

25. MythicPlay says:

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!

26. Brian H says:

How Illuminating.  Thanks David.

27. Micah Philson says:

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!

28. Aaron Laxton says:

i found this hard to watch, his voice is very monotone unlike simons

29. luisbvs says:

What just happened? Please explain… thanks…

30. Aravind K V says:

That's a fine, cool way of asking to support! I liked it a ton!

31. Stroheim333 says:

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.

32. Glen Berkel says:

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.

33. Adam J. Smith says:

Confounding! Tell me: this is the guy "Big Bang Theory" is imitating, isn't it?

34. wysiwyg43 says:

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.

35. Bill Ebert says:

lame.

36. Mis An Thrope says:

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?

37. Richard Jones says:

Way too much math.

38. UDAY KUMAR says:

coooool!!!!😊

39. Brent Salmon says:

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?

40. Dustywitch says:

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.

41. Nikki Rennardo says:

So electricity is more like a wave than a river?

42. Charles Jones says:

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.

43. Scott Smith says:

And if you take into account AC current….. yea, they are not moving, just the field around them

44. Cambria399 says:

why then does the filament get hot in a dc incadenscent light bulb

45. Jason Anderson says:

yick…

46. John Floyd says:

daven looks like he really has to shit

47. ThatGuyThatGames says:

at first i was comparing the speed of electricity to a drag car, now I'm comparing it to a turtle.

48. JOHNSON! yes sir! says:

so your saying if I drop car battery in my backyard pool I have ample time to get out?

49. jugosever says:

If the electrons move that slowly how can they carry enough energy to power an electric motor, for example?

50. Ethelred Hardrede says:

Now I want to know how well the equation fits with superconduction.

51. RonJohn63 says:

I knew it was slow, but not that slow.

52. Dominic Fong says:

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.

53. Shyam Dambhare says:

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

54. Today I Found Out says:

Now that you know all about the speed of electricity check out this video and find out When a Speed Limit Comes Into Effect: