Recent content by Danyon

I often hear that a superconductor can hold a current indefinitely, I have a thought experiment which relates to this claim. Consider a closed square loop of superconducting wire, this wire carries some current. Will the electrons in the circuit transfer momentum and energy to the metal lattice...

That's really bizarre, could you please show the math here? Just looking at the scenario its hard to imagine how something isn't violated here

I can't find any clean ways to resolve the problem, I've been thinking about this for months, I came across this example when I was trying to design a reactionless thruster. I hope that linear momentum is violated, it would be quite useful for spacecraft

Consider two objects, "A" and "B", each having mass 1kg. Object "A" moves downward towards object "B" and collides with the extended arm of object "B". Let's say for the sake of argument that during this collision object "A" lost one unit of momentum and 0.5 joules to object "B" (This value does...

Consider moving a negative charge in the direction of current of a wire. This will cause the stationary positive charges in the wire to appear to move in the reference frame of the moving negative charge, this will cause length contraction on the positive charges and creates a net positive...

In the case of current in a wire there are positive charges in the wire that are needed for the effect to occur. Given that there are no positive charges near or around the electron as it moves through free space I can't see how its magnetic field can be attributed to an electric field in...

Okay, "explained in terms of" is probably the wrong way to put it then, what I mean is, the special relativity picture of magnetism says that the magnetic field in one reference frame is actually an electric field in another reference frame (in the current in a wire situation). I'm asking, can...

I've read in various places that magnetism can be explained in terms of the effects of special relativity. However, all of the explanations of this only mentioned the case of current flowing in a wire. Can special relativity explain the magnetism of free flowing electrons and other moving...

Consider a 5 meter by 5 meter and 1cm thick superconducting plate, now place a very strong neodymium magnet against the underside of the plate.The plate is big enough so that the magnetic field does not go around the plate. Does a magnetic field penetrate the plate or is it blocked completely...

Is there any easy way to determine the charge on a van de graaff generator based on the voltage?

Will a laser diffract through a single slit if the laser beam width is smaller than the slit? Such that the laser beam can pass though without touching the sides.

Which wire do you say is emitting radiation? Would it still be the case if the device was only used once?

That's a shame. Oh well

Okay, thanks. I've been wondering about this for a while. would there be any near field effects in this example?

Okay, thanks. I just got a bit mixed up