Question about electricity

[weeman]

So I'm doing an internship at Denver Center Theatre Company, and I met with my intership supervisor yesterday and we were talking about electricity. He told me that in things like superconductors, electrons can be exceeded well beyond the speed of light, because due to superconductors being kept at such cold temperatures, they generate very little resistance.

I got somewhat confused because everything I've learned as an amateur physicist tells me that nothing travels faster than light. He said that when physicists say this, they are typically referring to physical light (photons).

The interesting thing that I suddenly realized, is that electrons, in an electrical current, travel at the speed of light. Correct? So I began to question my own knowledge. If an electron has mass, how does it travel at the speed of light? According to Einsteins equation E=mc2, the faster an object of mass travels to C, the more mass it has, therefore requiring more energy.

So how can an electron even travel at C? Furthermore, how are scientists able to use superconductors to break the C boundry? Was my supervisor correct?

 

[MeteorWayne]

Well your supervisor was wrong. Electrons don't exceed c. Tell him that at your own peril.

And the concept of an electron traveling from one end of the wire to the other in order for there to be flow is incorrect. It's more like you push one in at one end and another falls out the other end. Think of a hose filled with water. When a molecule of water leaves the faucet when Jerry turns it on, it's not that same molecule that immediatly squirts Tom in the face; it's the molecules that were already in the hose. Electrons in a wire work the same way.

MW

 

[weeman]

Right. I know that the flow of electrical current is simply the flow of an electron, jumping from one atom to the next, by means of an external force.

I tried to tell him he was wrong, but he made it sound as though I was misinformed.

 

[Mee_n_Mac]

Right. I know that the flow of electrical current is simply the flow of an electron, jumping from one atom to the next, by means of an external force.

I tried to tell him he was wrong, but he made it sound as though I was misinformed.

You weren't (misinformed), he was.

 

[centsworth_II]

Right. I know that the flow of electrical current is simply the flow of an electron, jumping from one atom to the next...

Your supervisor may be absolutely wrong. But is it really a good idea to make a point of proving it? It is funny though that an electron's movement through a wire can be slower than a snail's pace.

"So, how fast do electrons move in typical copper wire?
... [about 10cm per hour] ....The electrons actually drift rather slowly through the conductor.
However, the electric field, or changes in the electric field due to motion of the charges
moves very close to the speed of light (3x108m/s) and therefore electricity appears to be
instantaneous."http://www.physics.ohio-state.edu/~kass/P132/P132_ch27.pdf

And that's in a DC (direct current) circuit. Most of the electricity we use is of the AC (alternating current) sort. In this case, the electrons really go nowhere at all! The current changes direction 50 or 60 times a second so the electrons move a fraction of a millimeter one way, then a fraction the other way, over and over.