# Magnet in a pipe?

1. Nov 24, 2012

### cragar

Lets say I have a superconducting pipe that is infinitely long.
Now I place a magnet in the pipe, will the magnet stay placed in the pipe due to the meisner effect? And the magnet is in a Constant gravitational field.
And the pipe is vertical in the G field.

2. Nov 24, 2012

### K^2

I'm pretty sure it will drop slightly, until it causes the superconductor to produce a sufficiently strong magnetic field on the inside to support the magnet against gravity.

3. Nov 24, 2012

### cragar

Even if the magnet is light it will need to move a little bit so the Lorentz force can push the electrons and create a strong enough current. What If I hold the magnet there fore a little
bit and then let go, will it move a little bit.
And ok lets assume the magnet is stationary in the pipe, now I shoot a marble off of it,
will the magnet move a little bit and then come back to a stationary position or will it continue down the tube. It seems like it will eventually come to rest.

It seems like it might not need to move down the pipe to be held up.
What If I had a stronger magnet that weighed the same and just the presence of the magnet created that same current in the pipe as the weaker one did with the movement, it seems like it would be held up right away with out any movement?