The axis of evil
Stories from Physics for 11-14 14-16
The cosmic microwave background radiation is nearly uniform in all directions. However, in 2003, data from NASA’s Wilkinson Microwave Anisotropy Probe found an unexpected pattern in the temperature data, which the journal Nature listed, in 2015, as one of six baffling physics results that can’t be resolved. At one scale, the random fluctuations of the radiation seem to align in a preferred direction that has been dubbed the ‘axis of evil’ as it threatens models of the nature of the background radiation. A second anomaly in the data is the so-called ‘cold spot’, an area along the ‘axis of evil’ with a temperature around 70 μK less than the mean temperature of the background radiation. The ‘cold spot’ has been associated with a billion-light-year-diameter ‘supervoid’, a huge empty space that is devoid of galaxies.