CD shattering, DVD shattering (more recently Blu-ray shattering) and optical disc shattering, a phenomenon also known as exploding CDs, occurs when a optical disc shatters inside a high speed optical disc drive (48× or higher CD-ROM unit) with a loud cracking sound. Typically, the disc and the drive will be ruined. Fragments of the broken disc may be expelled through the front of the drive at high speed and cause physical injury.A disc shatters when it fails to support the centripetal force required to keep all parts of the disc moving circularly. The velocity of the edge of a 120 mm disc rotating at 10,350 RPM is approximately 65 m/s. (234.1 km/h, 145.5 mph) To remain in circular motion about the spindle, the disc edge accelerates at about 7,200 G. The force causing this acceleration is transmitted through the disc itself and is balanced by an opposite force on the other side of the disc. Thus, a disc begins to fail when it can not handle these forces, and a failing disc can then completely shatter due to the imbalance of forces around the disc.