For one, general relativity alone can not explain the observed motions of galaxies or the way the universe seems to expand. (discovermagazine.com)
But the existence of galaxies outside our own posed another question, about the apparent motions of those galaxies away from one another. (science.sciencemag.org)
In the last decade, two independent and sometimes competitive research groups have used some of the most luminous objects in the universe — exploding stars dubbed Type Ia supernovas — to gauge the distances and motions of galaxies with unprecedented precision. (discovermagazine.com)