Two analyses of a million galaxies show that their distribution may not be symmetrical, which may mean that our understandings of gravity and the early universe are incorrect

Space 18 June 2022

The Sculptor Galaxy

Stocktrek Images, Inc. / Alamy Stock Photo

The mirror symmetry of the universe may be in trouble. Based on our current understanding of the large-scale structure of the cosmos and what we know about how gravity works, if we look at how galaxies are distributed throughout the universe and then compare it with its mirror image, the two should be basically indistinguishable. But two separate analyses of our best map of galaxies have now found that this principle, called parity symmetry or just parity, doesn’t seem to hold true.

Each analysis examined galaxies from the …