Is information (in classical physics) transferred at light speed? Or is it assumed to be instantaneous? What is actually going on in examples such as:
1) An electron in space is surrounded by a capacitor which is connected to a closed circuit. Microsecond by microsecond, what happens?
If I have two perfectly rigid boxes, one behind the other, and I push one on the side on a frictionless floor, when will the other box know it's being pushed?

Question

Is information (in classical physics) transferred at light speed? Or is it assumed to be instantaneous?  What is actually going on in examples such as:
1) An electron in space is surrounded by a capacitor which is connected to a closed circuit.  Microsecond by microsecond, what happens?
If I have two perfectly rigid boxes, one behind the other, and I push one on the side on a frictionless floor, when will the other box know it's being pushed?

anonymous · Answer

i think its instantaneous

anonymous · Answer

Assumed to be so or is?

anonymous · Answer

thats what i think lol

anonymous · Answer

yes the information is rtansferred at the speed of light

anonymous · Answer

really?  So what would happen in the electron problem?  The moment an atom of the metal in the switch touches the other side, the electron moves?

anonymous · Answer

first tell which type of current is in the circuit ac or dc

anonymous · Answer

you have a battery (dc) of some EP hooked up to a switch and cap in series.  an electron is in the space between the cap plates.  You switch it on.

anonymous · Answer

electron will move towards +ve terminal

anonymous · Answer

instantaneous current will start flowing in circuit

anonymous · Answer

assuming it's a perfect switch of course

anonymous · Answer

You need 'stuff' to transfer information. No thing (no 'stuff') can travel faster than light, so no. AT BEST, information (about ANYTHING) travels AT the speed of light, never above.

anonymous · Answer

That was the relativistic answer. Qunatum mechanics muddies the waters considerably (google quantum entanglement).

anonymous · Answer

is information ok

anonymous · Answer

yeah @henpen  I heard about that

anonymous · Answer

But rereading the question, as long as you aren't doing electromagnetism you can approximate that it does.

anonymous · Answer

eventually we'll have quantum computers with entangled memories - and finally no lag!

anonymous · Answer

OK.  so the current has to reach the capacitor, as I understand it.

anonymous · Answer

An good example is about 4 mins into http://www.youtube.com/watch?v=Yi1H_9JOwkI

anonymous · Answer

But what about the boxes example?

anonymous · Answer

other box will start accelerating as soon as ist box starts motion

anonymous · Answer

Are all your questions to do with the original information question?

anonymous · Answer

As in, do we assume that information can't travel faster than  for that question?

anonymous · Answer

@henpen  I don't understand what you're saying.  But I watched the video, and it seems to me that all forces can transfer their information at the speed of light (at most), since that information is transferred through the force's field particles (if I am not mistaken).

anonymous · Answer

Then only quantum entanglement is the instantaneous one.
And I'm not going to pretend to know how that works.

anonymous · Answer

Basically, it's impossible to have a totally rigid body. If you have light year long scissors (even really strong), if you close then quickly they will bend.

anonymous · Answer

okay then the stress/microscopic compressions in the first box will delay the force's movement across it by however much.

anonymous · Answer

But is my assumption about the light speed of forces true?

anonymous · Answer

Yes and Yes.

anonymous · Answer

max speed of light speed*

anonymous · Answer

OK.  Cool.  that answers a lot, thanks!