Science Buddies: "Ask an Expert"

I'm competing in astronomy and my project is about suns prominences. A prominence is a part of suns atmosphere that gets colder and denser and wants to fall to the surface but the suns magnetic field keeps it floating over the surface. I want to simulate that. I've tried taking a glass board and a aluminium and bronze wire. I made a U shape out of the wire and I put it so it's parallel with the board and I've run DC (with a rectifier) only through the wire. What should happen is inducing electricity in the board so that its magnetic field pushes the wire away from it. I was told to use a diamagnet so I used a glass board. I don't know if the experiment worked. The wire did get away from the board, but it also got a little deformed every time. I thought maybe it got away because it got deformed so I put the board on the other side of the wire and it got away from the board again. But 15 min later when I switched sides again, it didn't move at all. And another problem is that when I would turn off the electricity the wire wouldn't return to it's original position, it would stay away from the board. I assumed it did so because the force got strong enough when I got the electricity running to push the wire away and deform it a little to do so, but when I turned it of there wasn't any force to return the wire to the starting position. Do you know why? Do you know how I can get my experiment to work or do you have another idea how I could demonstrate the behaviour of the prominences?

I wish I had a better answer for you, but I'm afraid I'm not quite understanding your experimental procedure. It sounds like a very interesting experiment.

What do you mean by a "glass board"? Glass is not normally a conductor and is not magnetically active. I'm also not sure what your experimental procedure is from your description.

Note: this isn't really my field, so I'm not sure I'll be able to provide an answer even if I do understand the experiment better, but I'm willing to try.

puza - I echo Ray's comments but am not an expert in this specialty either. A wire conducting an electric current will certainly generate a magnetic field around it and that can be attracted to or repulsed from another magnetic field. It's possible that glass is slightly diagmanetic (not as much as say, pyrolytic carbon) so your experiment may be valid. However, if you observed that the wire was repulsed by whatever this field was, but fails to return to it's original position perhaps you did stress the wire with too great a current. If you are only trying to note deflection and return, you might reduce the current in the loop, noting small movements when current is applied or removed. That should support your thesis.

Rick Marz