Ferrofluid

A colleague and I spent some time playing around in the lab with a ferrofluid and a strong neodymium magnet. And a camera, of course. Ferrofluids are supercool and look almost unreal. A few more pictures can be found in my gallery here, and loads of them on Flickr - many a lot better than mine.

With the magnet closer the spikes become smaller and denser. The curve hexagonal pattern of light dots in the lower part comes from light scattered off the tips of out-of-focus spikes. The spikes form a hexagonal pattern on the surface as clearly seen below.

A hexagonal pattern of large spikes.

I didn't have a green lamp, so the colour comes from shining a white lamp through a solution of nickel salt.