We all know that dark energy works against gravity, pulling matter apart. We didn’t know, until now, that dark energy has weakened. Well, at least in comparison to its level of strength when the universe was young. Astronomers believe this is true based on observations of a new dark matter map. From Space.com:
The dark matter map was created with observations from the Hubble telescope of a large galaxy cluster called Abell 1689, located 2.2 billion light-years from Earth. This cluster is famous as a stunning example of gravitational lensing – a phenomenon predicted by Einstein that happens when massive objects warp the space-time around them, causing even light to travel on a bent path when it passes by.
Since the universe has been continually expanding since its birth, it was once much denser than it is now; and the extra-heavy cores of galaxy clusters suggest they were born during these early stages when such dense conglomerations of matter were around. But if galaxy clusters did get an early start in forming, you’d expect to see a lot more of them around today. The force of dark energy suppressed the formation of galaxy clusters, and counteracted, if you will, the head start clusters had in forming.
For all the questions this answers, it raises dozens more…