BigB(1)

by : Tristan Vey

The Big Bang is there, all around us. In effect, we are bathed by a diffuse form of radiation called fossil radiation, inherited from the original explosion (this first form of light being emitted «only» 380 000 years after the Big Bang). But observing this very cold microwave radiation (a mere 3 degrees above absolute zero) and whose existence was predicted in the 1940s only to be observed for the first time in 1964, is no easy matter. This signal is in effect largely drowned out by the surrounding electromagnetic radiation and it takes all the cleverness of the scientific community to isolate what George Smoot, Nobel Prize for Physics 2006, has called the «face of God».

Today, The Planck European satellite launched in 2009 and situated 1,5 million kilometers from Earth ( a place of equilibrium between the gravitational fields of Earth and the Sun called a Lagrange point) is prepared to give a first glimpse of a global view of the sky where one can see both the illumination from our Galaxy and this luminous echo from the Big Bang. «The structure of the fossil radiation [in red and yellow in the image] is more manifest in the regions top and bottom of the image, where the illumination from our Galaxy is weaker», explains Jean-Michel Lamarre, the scientist responsible for one of the two principal measurement instruments on board the satellite.

No interpretation for months to come

In order to observe only the cosmological radiation from the Big Bang, a great deal of analysis is still necessary. «The different phases of the interstellar environment emit in frequency bands, in ‘colors’ that are different», explains Jean-Loup Puget, research director at CNRS, Institut d’astrophysique spatiale. These ‘colors’ can be used to separate the light in our Galaxy, at the center of the image, in order to extract the fossil radiation. «Precisely in the same manner that the human brain is capable of isolating the voice of one person speaking in the midst of a group in full discussion», adds Jean-Loup Puget. One will thus need to wait until the end of 2012 for this incredibly precise and detailled image of the «face of God» to become public. It should bring with it a great deal of intelligence on the birth and first few instants of our universe, and permit us to better understand the rythm of its expansion.

In the meantime, this first ovenfull of data brings information on our own Galaxy, the Milky Way. We will nonetheless need to wait for astrophysicists to interpret this data, which coud take months, if not years. Work for an ant colony whose goal is ever the same : to better understand the workings of our universe.