3-D visualization of the magnetic field of a U-magnet.
Available at Visuals Unlimited.

Science concept images

Conceptual Stock Photography, Conceptual Stock Imagery, Stock Conceptual Photography,
Stock Conceptual Imagery, Conceptual Stock Illustration, Stock Conceptual Illustration,
Creative Stock Photography, Offbeat Photos, Weird Images, Odd Pictures, Strange Concepts.
Whatever you want to call it.
It's what we do.  We see things a little differently.