You probably don't think of them that way, but Blu-ray discs have a gorgeous color. In fact, the same physics that gives butterfly wings and housefly eyes their iridescent shine are also at work on Blu-ray. All are examples of what physicists call structural color, which are colors created not from pigments, but from translucent, microscopic shapes that capture light and reflect it in such a way that it appears colored to the human eye.
Bracelets or belts that track your activity and vitals may soon be a thing of the past. Engineers from the University of Illinois at Urbana-Champaign and Northwestern University have produced a health-monitoring device that looks like a Band-Aid. The thin, soft patch can stick to and move with the skin, all while wirelessly sending vital updates to your designated cellphone or computer.
Gold, precious forever but especially lately, is a tricky metal. Bound up in consumer electronics, jewelry and the ores that it comes from, gold is difficult to extract, and most modern processes do it with a highly toxic combination of cyanide salts. The cyanide leaches the gold out, but the cyanide can seep into the ground, causing environmental problems and posing threats to human health.
