It took a team of physicists all this time to figure out how
DVDs workS  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 DV