Mythbusters on the Discovery Channel recently tackled the legend of exploding CDs. The legend goes that flawed CDs that are spun to 30,000+ r.p.m. in 50+X CD-ROM drives have a tendency to explode.
Well, turns out that the legend is somewhat true. The guys from Mythbusters were able to get some CDs to explode by spinning them really, really fast on a fake CD-ROM drive powered by a router (the wood-working kind).
(Why a router? Turns out that they couldn’t get a commercial CD-ROM drive to spin as fast as it was supposed to. A 52X drive is supposed to spin at 30K r.p.m., but they couldn’t get one to spin past 20K.)
They spun these CDs (and exploded many of them) in front of an unprotected gelatin mold of a human. The damage was exceptional. The exploding CDs spun outward like ninja stars, doing considerable damage to the dummy. The best results were from CDs that they “pre-damaged” to simulate wear-and-tear, including one they microwaved.
(Remember, however, that in real-life the CD is inside the CD-ROM drive, giving you more protection than Jello-man. Although, in one expirement, the exploding CD dented and deformed the metal case, leaving creases in it.)
The most fun was when they plugged their fake CD-ROM drive-router concoction into a 220-volt outlet. They’d plug it in, and the CD would last perhaps a half a second before vaporizing in a cloud of shiny fragments.
They had a high-speed camera running during the experiments, and in super slo-mo playback, you’d often see the CD start to wobble just before detonation. It appeared that at a certain speed, the harmonics would getting the thing rattling in the drive (moving up and down, as well as round and round), and even flexing considerably. Some of them looked like pizza dough being tossed on the air. The end came very quickly after.
…a quick jerk at the tool and the CD slid out of the holder and contacted the carpet whilst spinning at ungodly speeds. It peeled out a bit in front of me and proceeded to make its way to the door at a very high speed. On contacting the closed door, the CD did a most unexpected thing: it first bounced back a few inches, and then, when it hit the door again, it jumped straight up the door and struck the ceiling, exploding into thousands of fragments which rained down on the entire room.
He has videos of a lot of his expirements, and they’re entertaining as all get out. Ah, good fun in the name of science.