Astronomers have assumed for decades that the Universe is expanding at the same rate in all directions. A new study based on data from ESA’s XMM-Newton, NASA’s Chandra and the German-led ROSAT X-ray observatories suggests this key premise of cosmology might be wrong.
![](https://scx1.b-cdn.net/csz/news/tmb/2020/doubtsaboutb.jpg)
Source:
https://phys.org/news/2020-04-basic-assumption-universe.html