How’s this for cool? Normal, everyday Scotch Tape (or sellotape, for you British readers) gives off x-rays when pulled off the roll in a vacuum. According to this article at USAToday.com, UCLA researchers
[used] a machine [to peel] ordinary Scotch tape off a roll in a vacuum chamber at about 1.2 inches per second. Rapid pulses of X-rays, each about a billionth of a second long, emerged from very close to where the tape was coming off the roll.
That’s where electrons jumped from the roll to the sticky underside of the tape that was being pulled away, a journey of about two-thousandths of an inch… When those electrons struck the sticky side they slowed down, and that slowing made them emit X-rays.
The UCLA eggheads hope to refine the process enough to create cheap x-ray equipment for paramedics, developing countries, and places where electricity is hard to come by (like a ranger station in a national park, for example).
Should office workers worry about getting cancer from Scotch tape? Apparently not. The phenomenon only occurs when Scotch tape is unrolled in a vacuum. So you should be fine… unless you’re taping together documents in outer space!