The CMB is radiation left over from an early stage in the development
of the universe, and its discovery is considered a landmark test of the
Big Bang model of the universe
I have been completely astounded. I never believed when we started that anybody would ever measure the non-uniformities of the CMB, let alone the polarisation, which is now what we are seeing.
. When the universe was young, before the formation of stars and planets, it was denser, much hotter, and filled with a uniform glow from a white-hot fog of hydrogen plasma. As the universe expanded, both the plasma and the radiation filling it grew cooler. When the universe cooled enough, protons and electrons combined to form neutral atoms. These atoms could no longer absorb the thermal radiation, and so the universe became transparent instead of being an opaque fog. Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch, and the event shortly afterwards when photons started to travel freely through space rather than constantly being scattered by electrons and protons in plasma is referred to as photon decoupling. The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time (and wavelength is inversely proportional to energy according to Planck’s relation). This is the source of the alternative term relic radiation. The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling.ackground
It is possible for the interaction of CMB light with dust in our galaxy to produce a similar effect, but the BICEP2 group says it has carefully checked its data over the past three years to rule out such a possibility.
Prof Andrew Jaffe from Imperial College London, UK, works on a rival telescope called POLARBEAR. He commented: “A lot of this is technology driven. And the next generation of experiments, like the next generation of POLARBEAR, SPIDER and EBEX, and things like that, will have far more detectors and will go after this signal and hopefully drag out much more detail.”
One of those pioneers, Prof Alan Guth from the Massachusetts Institute of Technology, to
Source : BBC
“I think it is absolutely amazing that it can be measured and also absolutely amazing that it can agree so well with inflation and also the simplest models of inflation – nature did not have to be so kind and the theory didn’t have to be right.”
“I can’t tell you how exciting this is.
Inflation sounds like a crazy idea, but everything we see today – the galaxies, the stars, the planets – was imprinted at that moment,
in less than a trillionth of a second.
If this is confirmed, it’s huge.”