The information hidden in the CMB spectral distortions in Planck maps and beyond

The deviations of the CMB spectrum from a blackbody spectrum represents an important unexplored window in cosmology. Our knowledge of the CMB spectrum has not changed since the COBE-FIRAS space experiment 25 years ago. In the near future we may have a second CMB spectrum experiment which would improve upon the sensitivity of the COBE-FIRAS by 3-4 orders of magnitude. There is high probability of surprising discoveries with such a jump in sensitivity. I will review the physics of CMB spectral distortions and what information we might gain from them about our Universe and fundamental physics. I will also show results from the recently concluded Planck experiment which have, for the first time since COBE-FIRAS 25 years ago, given us new information about the CMB spectral distortions.