Scientists have long theorized that you can create matter from light by colliding photons, but proving that theory has been a different story -- you need the right high-energy particles to even think of trying. However, it looks like that once-impossible dream is close to becoming reality. Researchers at Imperial College London have discovered a technique that should produce electrons and positrons by colliding two sets of super-energetic photons. To create the first batch of photons, you have to first blast electrons with a laser, and then shoot them at a piece of gold; you produce the other batch by firing a laser at the inside of a small gold can to produce a thermal radiation field. If you collide the two photon sources inside the can, you should see electrons and positrons spilling out.