All Galaxies Found To Rotate Once Every Billion Years

 A new study by an international team of astronomers from Australia, China and the United States has discovered that all galaxies rotate once every billion years, no matter the size.
 According to the study, it was found that by using simple mathematics, it was possible to demonstrate that all galaxies of the same size have the same average interior density.
 “The Earth spinning around on its axis once gives us the length of a day, and a complete orbit of the Earth around the Sun gives us a year,” said Professor Gerhardt Meurer, from the University of Western Australia node of the International Centre for Radio Astronomy Research. “It’s not Swiss watch precision, but regardless of whether a galaxy is very big or very small, if you could sit on the extreme edge of its disk as it spins, it would take you about a billion years to go all the way round.
 “Discovering such regularity in galaxies really helps us to better understand the mechanics that make them tick — you won’t find a dense galaxy rotating quickly, while another with the same size but lower density is rotating more slowly.”

Read more about this fascinating story at: http://www.sci-news.com/astronomy/galaxies-behave-like-clocks-05817.html
Or read the full study at: https://arxiv.org/abs/1803.04716
Image: Messier 101 via NASA / ESA / K. Kuntz, JHU / F. Bresolin, University of Hawaii / J. Trauger, JPL / J. Mould, NOAO / Y.-H. Chu, UIUC / STScI.