• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Cool magnet stuff

athon

Unregistered
A
Joined
Aug 7, 2001
Messages
9,269
I need some ideas, people. I'm constructing a school show on magnets, and so far have the basics but want some awesome looking demonstrations. I've got my hands on some large rare earth magnets and have made a decent sized gauss rifle, which works well. I considered making a rail gun (I want to discuss Lorentz forces as I go a little into the topic of electric fields), but am about to scrap that idea as it just doesn't look feasible.

So, anything else I can make? It has to be cheap and relatively safe. There was something I read ages ago about using a steel bearing or something, dropping it down a pipe... can anybody remind me how that works?

Athon
 
Ferrofluid, AKA magnetic fluid, is some of the coolest stuff in the world. It's basically very small iron filings suspended in oil. I saw a great sculpture based on ferrofluid that did a show timed to music.
 
athon said:
Yeah, that's the ticket. The 'slow fall' pipe is what I'm looking for.

And ferro fluid would be interesting. I'll look into it.

Athon
Click to expand...
Yeah, I like it, too, but the opaque pipe makes it harder to show a large group.
Some of the magnet distributors have ready made kits and good external links, too. Check them out, also.

Dave

ETA: The pendulum and ramp experiments can be modified for large groups, and making a water or wind driven generator can be instructive.
 
Last edited:
True. I've already started to consider how to get a large group to see inside the pipe; mirrors strategically place with a good light source is the closest I can come up with. I'll work on it.

Athon
 
CaveDave said:
http://www.amasci.com/neodemo.html
I can maybe find more if those don't suit you.
Click to expand...
thanks for the link.

i am looking for a simple, small experiment, robust enough to yield real data but light enough that i can carry (a version) on the road. aim is to demonstrate sustained nonlinear dynamcis ("chaos") and difficulties in forecasting even "simple" physical systems; ideally someone else has written down a hamiltonian/ODE somewhere...

is there a simple configuration (a pendulum over fixed magnets) that would yield long-lived if transient dynamics? the nicest data i've seen involves a magnet over liguid helium, a bit hard to take in your hand luggage these days...
 
lenny said:
i am looking for a simple, small experiment, robust enough to yield real data but light enough that i can carry (a version) on the road. aim is to demonstrate sustained nonlinear dynamcis ("chaos") and difficulties in forecasting even "simple" physical systems; ideally someone else has written down a hamiltonian/ODE somewhere...

is there a simple configuration (a pendulum over fixed magnets) that would yield long-lived if transient dynamics? the nicest data i've seen involves a magnet over liguid helium, a bit hard to take in your hand luggage these days...
Click to expand...

If you don't need to have magnets, you might try a chaos pendulum. For a simmulation see:
www . butterflystation.net/arcade/pendulum/pendulum.html

Sorry I can't make it a clicky yet.

/Hans
 
lenny said:
is there a simple configuration (a pendulum over fixed magnets) that would yield long-lived if transient dynamics? the nicest data i've seen involves a magnet over liguid helium, a bit hard to take in your hand luggage these days...
Click to expand...
Several years ago, my neice and nephew and mom and I went to a San Antonio museum that had an attached "science exploratorium" part, and there was a display that, IIRC, had a long armed free swinging pendulum with a ring magnet at the end swinging over a metal plate on which you could place disc magnets in different places and polarities to watch the patterns of the swinging change around the various attractors and repellors. Kind of cool. the plate may have been curved to match the swing radius.

Does this help?

Oh, and here is Grundar's link:
http://www.butterflystation.net/arcade/pendulum/pendulum.html

Cheers,
Dave
 
athon said:
True. I've already started to consider how to get a large group to see inside the pipe; mirrors strategically place with a good light source is the closest I can come up with. I'll work on it.

Athon
Click to expand...
Use a long piece of either L-bracket or U-channel aluminum held at a very steep angle, so that a flat magnet slides in the crease. Works just as well, especially if you show comparison with a similarly sized piece of metal, just to show it's not friction that's slowing down the motion. Not as cool as the tube, but much better for presentation.

- Timothy
 
CaveDave said:
Several years ago, my neice and nephew and mom and I went to a San Antonio museum that had an attached "science exploratorium" part, and there was a display that, IIRC, had a long armed free swinging pendulum with a ring magnet at the end swinging over a metal plate on which you could place disc magnets in different places and polarities to watch the patterns of the swinging change around the various attractors and repellors. Kind of cool. the plate may have been curved to match the swing radius.
Click to expand...
There's a cute little commercially available desk version of this (that I have, and it's great fun to play with) that you can see here:

http://www.thinkgeek.com/geektoys/cubegoodies/6758/

- Timothy
 
thanks all for the suggestions.

CaveDave said:
Only 8" tall? I guess that would be OK for a desktop.
I would build a larger one for group demos, though.
Click to expand...
or make the plate transparent, and put the device on an OHP? not sure you could keep the pendulum in focus; but then it might look nice poping into and out of focus "chaotically"...
 
You must log in or register to reply here.

Back
Top Bottom