One Giant (Magnetoresistive) Leap for Mankind

I've been waiting for this one for a few years now: The Royal Swedish Academy of Sciences awarded the 2007 Nobel Prize in Physics to the two scientists who discovered the so-called giant magnetoresistive effect, a phenomenon that made the iPod (or, more specifically, the really tiny hard drive inside the iPod) possible.

Giant magnetoresistance (GMR) occurs in thin films composed of alternating magnetic and non-magnetic metal layers; hit the layers with a magnetic field, and the electrical resistivity within the layers drops by an unusually large degree (GMR shows 50% drop in electrical resistance, where regular magnetoresistance drop is around 5%). This property is useful when trying to read bits off of a magnetic hard disk—as the sensitivity of the head increases, one can make the bits much smaller on the disk, resulting in higher storage densities and consequently smaller drives.

Albert Fert of the University Paris-Sud and Peter Grünberg of Jülich
Research Centre independently discovered giant magnetoresistance in

I admit, I'm biased. But I love it when the non-particle physicists carry the day.—Martha Harbison