Galaxy clusters, which consist of thousands of galaxies, are important for exploring dark matter because they reside in a region where such matter is much denser than average. Scientists believe that the heavier a cluster is, the more dark matter it has in its environment. But new research suggests the connection is more complicated than that.
How did the universe begin? And what came before the Big Bang? Astrophysicists have asked these questions ever since discovering that our universe is expanding. New research suggests that subatomic heavy particles act as “primordial standard clocks,” offering a way of probing the beginning of space and time to determine which of the competing cosmological theories is correct.