World's tiniest lamp spans quantum and classical physics

The smallest ever incandescent lamp, made using a single carbon nanotube, has been created by physicists in the US. At 1.4 micrometres long and just 13 nanometres wide, the filament is invisible to the naked eye until it is switched on. Chris Regan's team at the University of California, Los Angeles attached a palladium and gold electrode to each end of the carbon nanotube, which spans a tiny hole in a silicon chip and is held in a vacuum. When electricity runs along the nanotube it heats up and begins to glow, releasing millions of photons every second, of which a few thousand reach the eye. "That makes the light relatively easy to see," says Regan. "Your eye is nearly single-photon sensitive." But it would make a poor reading lamp, he joke