A recent article in Physics.org “Missing Black Hole Report: Hundreds Found!” Oct 25, 2007 reported, “Astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away. The (these) massive, growing black holes, discovered by NASA’s Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their … Read more
In 1998, cosmologists made a remarkable discovery. Up until then they assumed that the expansion of the universe was gradually slowing down, due to the gravitational tug that individual galaxies exerted on one another. However, in 1998 observations of supernovas indicated some mysterious force was acting against the pull of gravity, causing galaxies to fly … Read more
In 1933 Fritz Zwicky a Swiss astronomer, was trying to measure the mass of a galactic cluster (a group of several galaxies) using two different methods. He tried to infer this mass from the speed of the galaxies. Just like kids on a merry-go-round have to hold on to avoid being ejected, galaxies are held … Read more