After Nobel talk — another controversy? October 3, 2006Posted by apetrov in Near Physics, Uncategorized.
So, the 2006 Nobel prize in physics was awarded to and (leaders of the COsmic Background Explorer (COBE) satellite experiment) “for their discovery of the blackbody form and anisotropy of the cosmic microwave background radiation.” Once again Thompson Scientific got it completely wrong (not even close!), proving that Nobel Prizes are not awarded by a simple majority of votes…
So, what is cosmic microwave background radiation (CMBR) and why it is anisotropic? There are nice reviews about that, including this one from the Particle Data Group, written by one of the awadrees. Anyways, the short story is that microwave background radiation, whose existence was proposed by George Gamow in 1946, comes as a consequence of the Big Bang. Hot plasma of various particles (including photons) produced in a Big Bang expanded and cooled down to a point when charged electrons and protons started to recombine into the neutral atoms, leaving photons decoupled. So this cooled-down photon bath now has a temperature of about 2.75 K (radiowave frequencies) and a spectrum of a black-body radiation. It turns out that this CMBR can be anisotropic due to various effects. For example, photons of CMBR would change energy (and thus temperature) in a gradient of some gravitational field (loose energy, or be redshifted, in an increasing potential and vice versa — the so-called Sachs-Wolfe effect). Or due to density fluctuations… Those anisotropies are tiny, of the order of thousandth of a percent! The observation of this effect, however, is a major discovery, as it connects us to the physics of the early universe.
So in 1989 a specialazed satellite experiment (above-mentioned COBE) was launched to study those anisotropies. The results were reported in April of 1992. The project leaders got the Nobel Prize!
There is, as always, a controversy. The thing is that in July 1983 an experiment Relikt (another link is here) was launched aboard the Prognoz-9 satellite to study cosmic microwave background radiation. The experiment carried out studies of the CMBR using only one frequency. However, in January of 1992, Andrei A. Brukhanov presented a seminar at Sternberg Astronomical Institute in Moscow, where he reported about the discovery of anistropy of CMBR. The results were published in journals Soviet Astronomy Letters and later in Monthly Notices of Royal Astronomical Society (see references above following the Relikt link).
Interesting story, don’t you think?