France''''s Albert Fert and German Peter Gruenberg independently discovered a physical effect in 1988 has led to sensitive tools for reading the information stored on hard disks. That sensitivity lets the electronics industry use smaller and smaller disks.

"The MP3 and iPod industry would not have existed without this discovery," Borje Johansson, a member of the Royal Swedish Academy of Sciences told The Associated Press. "You would not have an iPod without this effect."

The two scientists discovered a phenomenon called giant magnetoresistance. In this effect, very weak changes in magnetism generate larger changes in electrical resistance. This is how information stored magnetically on a hard disk can be converted to electrical signals that the computer reads.

Smaller disks mean fainter magnetic signals, so the ability to detect them is key to shrinking hard disks.

The first disk-reading device based on the effect was launched in 1998 "and this soon became the standard technology," the Nobel committee said.

Phil Schewe, a physicist and spokesman for the American Institute of Physics, said the prize honored "a terrific combination of great physics and huge practical application.

"I can hardly think of an application that has a bigger bang than the magnetic hard drive industry. Every one of us probably owns three or four or five devices, probably more, that depend on billions of bits of information stored on something the size of a dime."

Fert, 69, is the scientific director of the Mixed Unit for Physics at CNRS/Thales in Orsay, France, while Gruenberg, 68, is a professor at the Institute of Solid State Research in the west German city of Juelich. They will share the $1.5 million prize.

Asked if he''''d thought his discovery would have such wide application, Fert told The Associated Press, "You can never predict in physics.... These days when I go to my grocer and see him type on a computer, I say "''''Wow, he''''s using something I put together in my mind. It''''s wonderful."''''

A former rugby player and now avid sailboarder, Fert told France''''s Inter Radio that he planned to share some of the spoils of his winnings with colleagues.

"As usual when I get prizes, I share a little with my associates and then I will see," he said. "I don''''t know. I think I need new sails for my windsurfers."

Gruenberg told reporters gathered at his institute that he was not too surprised to win the Nobel. "Because I have received a lot of awards, I was often asked: ''''When will the big award come?"''''Gruenberg said.

He said the prize money would let him do research "without having to apply for grants for every tiny bit." He also said he knew early on that his discovery had commercial potential, which is why he secured a patent.

"When you have three children, it feels good to have an extra income," he said of the profit from his patent.

The Nobel announcement broke a streak of American wins from 2000 to 2010 that saw 20 people awarded the physics prize, of whom 16 were U.S. citizens or did their work at American laboratories and universities.

Last year, Americans John C. Mather and George F. Smoot won the physics prize for their work examining the infancy of the universe, studies that have aided the understanding of galaxies and stars and increasing support for the Big Bang theory of the beginning of the universe.

On Monday, two American scientists, Mario R. Capecchi and Oliver Smithies, and Briton Sir Martin J. Evans, won the 2010 Nobel Prize in medicine for groundbreaking discoveries that led to a powerful technique for manipulating mouse genes.

Prizes for chemistry, literature, peace and economics will be announced through October 15.

The peace award is announced in Oslo, while the other prizes are announced in Stockholm. The prizes, each of which carries a cash prize of $1.5 million, were established in the will of Swedish industrialist Alfred Nobel.

The Nobel prizes are always presented to the winners on the December 10 anniversary of the death of its creator.