Though DVDs have been consumer-grade tech for years, it wasn't until yesterday that scientists announced they were certain why they worked. Now we know that burning a DVD is really more like freezing it. DVD burning image by Filipe La Rotta.
It's been well known for decades that if you train a laser onto a specially-crafted layer of metal alloys on an optical disk, you create a storage medium that can hold an enormous amount of data for decades - and possibly centuries. But what's going on when the laser hits metal?
An international group of scientists based in Germany have been puzzling out that problem for several years. They're using one of the world's biggest supercomputers, JUGENE, to simulate what happens - nanosecond by nanosecond - when a laser hits the thin layer that gleams on the surface of a pristine DVD. For their most recent experiment, the group focused on one of the most popular alloys, or metal mixes, used to make DVDs. This alloy is nicknamed AIST, after its elements - AIST contains small amounts of silver (Ag), indium (In), antimony (Sb), and tellurium (Te). Like antimony (pictured at left), all these elements are very reflective, and together they give your DVDs that lustrous shine.