Nobel Prize in Physics 2006 to John C. Mather and George F. Smoot
John C. Mather and George F. Smoot share the Nobel Prize in Physics 2006, as just has been announced by the Royal Swedish Academy of Sciences. They are awarded for their research on cosmic microwave background radiation.
"It is an excellent experiment that converge two fields, astrophysics and particle physics", says Maarten de Jong, working as a professor in the FOM National Institute for Nuclear Physics and High Energy Physics (NIKHEF) in Amsterdam. He is very pleased at the award. "The results were a true breakthrough. They acknowledge the Big Bang theory. They also confirm our assumptions on the existence of so-called dark material in our universe."
Measuring cosmic microwave background radiation with the COBE satellite have provided an understanding in the origin of the universe. The results support the Big Bang scenario. After the Big Bang the cosmos has cooled down increasingly. In spite of all that a background of radiation remains. Other ‘bodies’ like objects and people also emit radiation. It depends on the temperature which wavelengths a body exactly radiates (the spectrum). In this case the scientists call the shape of spectrum black body radiation.
Ever since the Big Bang the universe has been expanding in all directions. At the same time the temperature of the cosmic microwave background radiation has been decreased to 2.7 degrees Kelvin. Mather and Smoot were the first scientists that were able to calculate this temperature accurately using the black body spectrum of the COBE satellite.
Anisotropy
The COBE satellite was also able to measure small differences in temperature from various directions. This is called anisotropy. The extremely small differences in temperature provide important information on the origin of the galaxies. Variations in temperature show us how matter started to coagulate. Without this proces matter would have been adopted a completely different shape and scattered equally all over the universe.
Future research
"The successor of the COBE satellite is the WMAP satellite. The WMAP satellite has measured the microwave background radiation in even more detail", reports Sijbrand de Jong, professor in Experimental Physics in the Radboud University, Nijmegen. He is also pleased at the Nobel Prize winners. "The results of the WMAP satellite have turned cosmology into a precision science. What's more, we came to the surprising conclusion that only about four percent of the density of mass and energy in the universe consists of the matter we are familiar with. We now know quite much about only four percent of our universe and we know nothing about the remaining part."
The successor of the WMAP becomes the PLANCK satellite that is still to be launched. This satellite is able to measure also the polarisation of the background radiation and in this way it will refine the image furthermore.
"All over the world great efforts are going on in astroparticles physics at the moment in order to point at the 96 percent mass and energy in the universe that is still unknown. The breakthrough of the COBE measurements have led to a renaissance of astroparticle physics, a field that is developing rapidly also in The Netherlands", according to De Jong. "About one thousand scientists are involved in the COBE project. This scale is absolutely necessary for a project like this. By awarding the Nobel Prize to Mather and Smith the Nobel Prize Committee show their appreciation of such a large project. At the same time they put the key figures on a pedestal."
For more information about the Nobel Prizes, please see also www.nobelprize.org or the Dutch FOM-website.