A rainbow reveals with colors what otherwise remains hidden: light is "refracted" by transparent matter, in this case water ...

Refraction—the bending of light as it passes through different media—has long been constrained by physical laws that prevent independent control over how light waves along different directions bend.

Guy Bartal, from the light refraction lab at Berkeley, talks with Scott Simon about the research they're doing on "invisible cloaks." Bartal overseas research in this lab, and is a co-author of two ...