Yesterday, I toured the Candian Light Source (CLS), probably the biggest science project in Canada of recent years.

It's basically a particle accelerator (a synchrotron, to be specific). But while in traditional particle accelerators, you're interested in getting particles up to great speeds and smashing them into each other or into other things, this machine takes a different approach.

One of the byproducts of turning atomic particles to keep them going in a loop at relativistic speeds is a whole bunch of energy in the form of light. So rather than smashing the particle into something (in this case, they're using electrons because they of their very low mass), you can just send tap into this at the point where the particle stream turns, and you get a beam of very intense light. So I guess you've just swapped a particle beam of, say, electrons for one of photons.

As it turns out, there are all kinds of things you can do with a really intense beam of light. These include high-resolution medical imaging, very fine etching of surfaces (like when you want to build nanobots), and determining protein structures.