It is not often that astronomers can see large changes in the brightness of a galaxy within a few years. Most galaxies change in brightness (and other properties) over millions or billions of years. So, when images of the distant 10-billion-light-year galaxy J0218-0036 showed that it dimmed to a twentieth of its previous brightness in … Read more
Primordial black holes (PBHs) are a very special type of black hole, thought to have formed from dense pockets of subatomic matter in the seconds after the Big Bang – and a new study reports what may be the first direct time. That may take years to prove, but the prospect is exciting. Black holes … Read more
In 1916, just a year after Albert Einstein published his general theory of relativity, Karl Schwarzschild used mathematical calculations to show this: If enough mass were packed into a very small volume, then this dense enough mass would create a region where the gravitational force is so strong that nothing, including light, could escape from … Read more