G. Ertl wins the 2007 Nobel Prize in Chemistry, A. Fert and P. Gruenberg in Physics
Gerhard Ertl of Germany won the 2007 Nobel Prize in chemistry on Wednesday for studies of chemical reactions on solid surfaces, which are key to understanding questions like how pollution eats away at the ozone layer.
Ertl's research laid the foundation of modern surface chemistry, which has helped explain how fuel cells produce energy without pollution, how catalytic converters clean up car exhaust and even why iron rusts, the Royal Swedish Academy of Sciences said.
His work has paved the way for development of cleaner energy sources and will guide the development of fuel cells, said Astrid Graslund, secretary of the Nobel Committee for Chemistry.
Ertl, who won the prize on his 71st birthday, told reporters that it "is the best birthday present that you can give to somebody."
"I am speechless," Ertl told The Associated Press from his office in Berlin. "I was not counting on this."
Ertl is an emeritus professor at the Fritz Haber Institute of the Max Planck Society in Berlin. Planck and Haber were themselves Nobel laureates, winning the physics and chemistry prizes in 1918.
The academy said Ertl provided a detailed description of how chemical reactions take place on surfaces and studied some of the most fundamental mysteries in that field.
Ertl showed how to obtain reliable results in this difficult area of research, and his findings applied in both academic studies and industrial development, the academy said.
"Surface chemistry can even explain the destruction of the ozone layer, as vital steps in the reaction actually take place on the surfaces of small crystals of ice in the stratosphere," the award citation said.
Americans Mario R. Capecchi and Oliver Smithies, and Briton Sir Martin J. Evans, won the 2007 Nobel Prize in medicine on Monday for groundbreaking discoveries that led to a powerful technique for manipulating mouse genes.
On Tuesday, France's Albert Fert and German Peter Gruenberg won the physics award for discovering a phenomenon that lets computers and digital music players store reams of data on ever-shrinking hard disks.
Prizes for literature, peace and economics will be announced through October 15.
The awards -- each worth $1.5 million -- will be handed out by Sweden's King Carl XVI Gustaf at a ceremony in Stockholm on December 10.
French scientist Albert Fert and Peter Grunberg of Germany have won the 2007 Nobel Prize for physics.
They discovered the phenomenon of "giant magnetoresistance", in which weak magnetic changes give rise to big differences in electrical resistance.
The knowledge has allowed industry to develop sensitive reading tools to pull data off hard drives in computers, iPods and other digital devices.
It has made it possible to radically miniaturise hard disks in recent years.
Matin Durrani, editor of Physics World, a journal published by the UK's Institute of Physics, said the award had gone to "something very practically based and rooted in research relevant to industry".
"It shows that physics has a real relevance not just to understanding natural phenomena but to real products in everyday life," he added.
Professor Ben Murdin of the University of Surrey, UK, said giant magnetoresistance, or GMR, was the science behind a ubiquitous technological device. "Without it you would not be able to store more than one song on your iPod!" he explained.
"A computer hard-disk reader that uses a GMR sensor is equivalent to a jet flying at a speed of 30,000 kmph, at a height of just one metre above the ground, and yet being able to see and catalogue every single blade of grass it passes over."
GMR involves structures consisting of very thin layers of different magnetic materials.
For this reason it can also be considered "one of the first real applications of the promising field of nanotechnology", the Royal Swedish Academy of Sciences said in a statement.
"Applications of this phenomenon have revolutionised techniques for retrieving data from hard disks," the prize citation said. "The discovery also plays a major role in various magnetic sensors as well as for the development of a new generation of electronics."
A hard disk stores information, such as music, in the form of microscopic areas that are magnetised in different directions.
The information is retrieved by a read-out head that scans the disk and registers the magnetic changes.
The smaller and more compact the hard disk, the smaller and weaker the individual magnetic areas.
More sensitive read-out heads are therefore needed when more information is crammed on to a hard disk.
"It's no good having computer hard-drives that can store gigabytes of information if we can't access it," said Professor Jim Al-Khalili of the University of Surrey, UK.
"The technology that has appeared thanks to the discovery of GMR in the late 1980s has allowed hard-disk sensors to read and write much more data, allowing for bigger memory, cheaper and more reliable computers."
Last year, US scientists John C Mather and George F Smoot won for their work examining the infancy of the Universe.
They were honoured for their studies into cosmic microwave background radiation (CMB), the "oldest light" in the Universe.