3 ms·

no way electrons speed is at centimeters or even millimeters per second, electrons travel at or close to speed of light.

by bedros 9y ago

azernik 9y ago
This is factually false: https://en.wikipedia.org/wiki/Drift_velocity https://en.wikipedia.org/wiki/Drift_velocity
jzwinck 9y ago
You're both right. Individual electrons can move at high speeds (not c), but the overall flow of electrons in a wire is very slow. This happens because individuals move in random directions but the group has a slow push with the current. Imagine people going to the shopping mall. Once in a while someone goes in and an hour or two later they come out the other door 10m away. But they travelled a lot more than 10m. You just didn't notice from outside.
- mbell 9y ago
  > Individual electrons can move at high speeds (not c) My memory may be off but as I recall the fermi speed in copper is only around 0.5% of c, rather far off. What does propagate at speeds on the order of c is the EM field, which is what most people are actually talking about when they think of electricity moving down a wire. But, it's still something around ~60% of c in a copper transmission line.
bedros 9y ago
this is actually correct, electric signals are actually about 6inches or 15cm per nano second (not seconds) https://en.wikipedia.org/wiki/Signal_velocity https://en.wikipedia.org/wiki/Signal_velocity
- mbell 9y ago
  You're describing the EM field, not the electrons themselves. Actually the two are moving in opposite directions as well.
GuB-42 9y ago
Electrons move fast, though not nearly as fast of the speed of light. However, they don't go in a straight line. So if you mark a single electron and look at it from afar, you will see it move very slowly. But if you look closer, you will see it jiggling around with a slight bias toward a direction. What goes at nearly the speed of light is the "message" that electrons should move a certain way. If you want an analogy, if you blow into a flute, even though the air is moving slowly, the sound travels fast.

no way electrons speed is at centimeters or even millimeters per second, electrons travel at or close to speed of light.

by bedros 9y ago

no way electrons speed is at centimeters or even millimeters per second, electrons travel at or close to speed of light.

azernik 9y ago

This is factually false: https://en.wikipedia.org/wiki/Drift_velocity https://en.wikipedia.org/wiki/Drift_velocity

jzwinck 9y ago

You're both right. Individual electrons can move at high speeds (not c), but the overall flow of electrons in a wire is very slow. This happens because individuals move in random directions but the group has a slow push with the current. Imagine people going to the shopping mall. Once in a while someone goes in and an hour or two later they come out the other door 10m away. But they travelled a lot more than 10m. You just didn't notice from outside.

mbell 9y ago
> Individual electrons can move at high speeds (not c) My memory may be off but as I recall the fermi speed in copper is only around 0.5% of c, rather far off. What does propagate at speeds on the order of c is the EM field, which is what most people are actually talking about when they think of electricity moving down a wire. But, it's still something around ~60% of c in a copper transmission line.

bedros 9y ago

this is actually correct, electric signals are actually about 6inches or 15cm per nano second (not seconds) https://en.wikipedia.org/wiki/Signal_velocity https://en.wikipedia.org/wiki/Signal_velocity

mbell 9y ago
You're describing the EM field, not the electrons themselves. Actually the two are moving in opposite directions as well.

GuB-42 9y ago

Electrons move fast, though not nearly as fast of the speed of light. However, they don't go in a straight line. So if you mark a single electron and look at it from afar, you will see it move very slowly. But if you look closer, you will see it jiggling around with a slight bias toward a direction. What goes at nearly the speed of light is the "message" that electrons should move a certain way. If you want an analogy, if you blow into a flute, even though the air is moving slowly, the sound travels fast.