Newsweek (March 29) -- You might not expect this, since CDs and DVDs are made to be spun around, but if you rotate one of them very quickly it will shatter, appearing to immediately become a bunch of chunks of sharp plastic. because the disc’s polycarbonate material is rather brittle, it can’t stretch much, and so the elastic energy leads stress to build up. At high speeds, it also becomes slightly uneven, like an askew car tire, and begins to wobble or vibrate, says Huseyin Sehitoglu, a mechanical engineer at Illinois.