The Nobel Prize of Physics of 2005 was given today to two american scientists, John Hall and Theodor Hänsch, and to one german, Roy Glauber. They share the prize for their works on Quantum Optics.
Hall and Hänsch won the prize for works in quantum optics that advanced the field of spectroscopy and enhanced the precision of spectrometers. Spectroscopy is the set of techniques used to analyze the light emmitted by atoms or molecules. Each atom or molecule absorbs light in a particular way and emmits this energy back to the environment in a specific pattern that defining a signature. This is how astronomers can tell you the elements in the composition of a distant star: they analyze its light and identify the pattern of different elements. This pattern also revealed that the electrons in atoms were placed in specific orbits ordered by integer numbers, what Bohr explained in his model for the atom. But this is another story.
Glauber is a guy that I only lnew from a classic work in statistical physics where he introduced what is called today as "Glauber Dynamics". It is a way to introduce and study a dynamics in the Ising model (someday I'll talk more about it), which is originally a static model intended to describe magnetic materials. But he won the prize working on quantum optics too and it seems that he somehow is the father of this area, he was the first to apply quantum mechanics to describe optics.
I found an interesting document explaining the contributions of these three physicists in the homepage of Hänsch. I think I could hardly explain that better. I copied the document and put it HERE.
You can find more information on the Nobel Prize Page itself.
The image was taken from the site of the Vienna University of Technology where it has the caption:
The purple light originates from helium atoms excited by intense laser light. The laser pulses propagate along the axis of the purple lobes (horizontally) through the helium gas, and the X-ray beam (not visible) is radiated in a beam several hundred micrometers in diameter in the same direction. Photo by courtesy of: J. Seres, Vienna University of Technology.