The Planck space observatory launched in 2009 by the European Space Agency was sent to observe the cosmic microwave background (CMB) radiation, a phenomena first predicted in 1948.
Named in honour of the Nobel Prize winning physicist, it has a higher resolution than previous probes (Cobe and WMAP) and therefore gives a more accurate picture, that it produces by rotating 360 degrees on all axes, measures tiny fluctuations in CMB, to build an image of the universe.
The image revealed the ‘blueprint’ of the universe, an early snapshot of it, before stars and galaxies formed. All that existed then was a vast sea of atoms and radiation. These atoms would eventually be pulled together by gravitational attraction and go on to form stars. By extrapolating backwards it is possible to infer the phenomena around the time of the big bang.
It largely conforms to expectations but not entirely. The tiny discrepancies are what is exciting physicists and could reveal evidence of the physics that occurred before the big bang.
The findings challenge fundamental concepts on the big bang, especially inflationary theory, the hypothesis that there was a catastrophic expansion less than a second after the big bang. We know the universe is expanding, but the new findings show it’s slower than previously thought (with a Hubble constant of 67.3 km/s/Mpc) which then leads to a slightly older universe than previous calculations (13.82 billion years).
It shows stronger fluctuations on one half of the image than the other. Also, larger than expected ‘cold’ regions (the blue bits) and deviations that are smaller than the measured deviations at smaller scales. The traditional predictions pointed to a uniform background radiation post big bang on all scales. The question now of course is, why?
What it really does confirm is that we still currently have little understanding of the universe – 96% of the universe is made of ‘stuff’ we still don’t understand. Only 4.9% of our universe is ‘regular’ matter, 26.9% dark matter, 68.3% dark energy (a bit more regular and dark matter, and a bit less dark energy than previously thought).
Physicists will now begin to re-evaluate underlying theories on how the universe evolved and is sure to signal the development of new theories on how it all began as we continue to see into the unknown and perhaps into a time before the big bang.