From the ground breaking and life saving to the wacky and implausible, Dr Karl Kruszelnicki reveals some of the best moments in science.
http://www.abc.net.au/radionational/programs/greatmomentsinscience/
Black hole basics
Even though it sounds totally crazy, astronomers are very confident that black holes exist. Our galazy is really old, it should carry at least 100 million black holes but we’ve found only a couple of dozen of them.