Axis of Evil

The term Axis of Evil was coined after coincidences were pointed out within WMAP data regarding CMB anisotropies and in conjunction with other directions and planes related to the solar system and Milky Way. Some of the coincidences were soon dismissed, and those remaining led to the coining of the term Axis of Evil. The coincident directions were on the order of 10 degrees' separation of axes whose directions should be totally unrelated. Such anisotropy-coincidences suggested some bias in the observation, or bias in the analysis that revealed coincidences, or due to some local astronomical phenomena that affects our view of the cosmic microwave background (CMB). The coincidences also suggested possible cherry-picking from among the many possibilities for such coincidences, or suggested some unsuspected aspect of cosmology. Some non-scientists (and some scientists humorously) suggest them to be evidence of Earth's special place in the universe.

Some coincidences were nearly immediately dismissed or effectively challenged, and more coincidences disappeared or weakened as additional data has become available (including the CMB-anisotropy data of Planck), though the latest anisotropy data still has at least one unexplained alignment. I personally don't find "within 10 degrees" to be all that surprising (even though it is true that the fractional probability of two unrelated directions within that angular distance is less than hundredth, and that of three would thus be less than a ten-thousandth), and I suspect much of the seemingly-unlikely coincidence is from cherry-picking among all the huge number of such angular measurements to select from (for which the birthday paradox applies).