Andreas Maier

A flashlight shines into the eye, and the retina responds with electrical impulses, like an echo, but not of sound, of light. This echo can be recorded, and it reveals not only how the eye is working but also how the brain is. After all, the retina is a piece of the brain that has been pushed out to the periphery.

A factory laser that cuts and welds metal on production lines has been made to work as a particle accelerator for the first time. Physicists took a standard ytterbium laser, its heart is a crystal the size of a palm, and turned its flashes into a tool for accelerating electrons to nearly the speed of light.