After viewing a short youtube video regarding diamagnetism I decided to repeat the experiment using my newly acquired green lab laser. The plan was very simple: slightly elevated flat surface, movable magnet, a few drops of distilled water and a carefully aimed laser beam. Un-fortunately the only flat surface I had on hand was a mirror which I instinctively turned up-side-up, thinking that is the correct way to go at it. Which is of course wrong as I found out later. The laser beam is supposed to bounce of the water surface for that experiment, not the mirror, and the effects on the water surface can be viewed when moving the magnet beneath that area.
(Video can be seen here: http://www.youtube.com/watch?v=2FvWtEdY4sE)
Frustrated by my obvious failure to reproduce a very very simple experiment I kept fiddling with the position of the magnet and the angle of the laser until I managed to get the laser to bounce off the mirror almost exactly at the center point of where the magnetic effect on the water was. Here is the result. Actually, there were two results. Not to far away ( the images were projected on my garage ceiling ) there was a different pattern. Image #2 below.
I can't say that I know what these images represent, but I imagine them being 2D representations of the underlying magnets effects on water. I'd be grateful if anyone could provide a more scientific explanation.
Anyways, here's what I used and how to reproduce the effects.
( Apologies for the blurry images, I couldn't with the tripod... again. )
Step 1: Equipment and Materials
Here is what you will need:
Any old laser will do red, green, blue, anything within your visual spectrum is just great. The only thing I'd suggest you avoid is using a strong laser. If you're into laser you'll know the ones I mean: the dvd burner, blue-ray, I can cut through duct tape ones. Since you'll be bouncing laser beams off all over the place, I'd urge you to not exceed 50mW and at the very least use some sunglasses for basic protection.
Here's the one I'm currently using: http://www.dealextreme.com/details.dx/sku.10096
Size doesn't matter, it's how you use it. :) No wait! Erase that! Get something small enough to handle with ease.
1 small puck-shaped neodymium magnet
The one I used came with the Arduino sensor pack 900.
1 small metallic strip
or anything that you can use to move the magnet without moving the mirror.
Distilled preferred, but not required.
something to elevate the mirror only slightly above the height of the magnet
[optional] a squid type third hand
It's a priceless tool and if you hadn't built one for your workshop I encourage you try. The most excellent instructable on how to do this is here: https://www.instructables.com/id/Third-Hand-A-multi-use-helping-hand-for-electro/
Step 2: Assembly and Alignment
Actually how to set this up should be evident from the previous step, so I'll just give some pointers about what I've observed to give the best results. It should be obvious that the whole point of having the mirror elevated is to avoid moving it or the laser. That said, when aligning the laser to the surface of the mirror, I found it best to make the mirrored beam only just barely pass the heat sink of the emitter. This makes it pretty easy to align the magnet correctly and will make the image on the viewing surface less distorted.
Don't be lazy like me and clean your mirror. Also use distilled water if you have any. As observable from the picture below, I neglected to do so and found that tiny particles of dirt and dust also make quite lovely images on their own. You can tell the image is from dirt if it moves when you gently blow into the water. The magnetic images will stay still unless you manage to move the whole thing all together.
How much water to use?
What you really want is only a few drops. Your goal should be to achieve as much height from your water drop as possible. This will give the strongest effect.
Step 3: Drawing Laser Flowers
Fire up your laser and move the magnet around. Should your laser have a good sized heat sink you can keep playing with it for a long while. Mind your eyesight and have fun. Below are some of the other images I've taken.
Kind regards, Vince.