On the twelfth day of advent we celebrate Stephen Hawking's contribution to cosmology.
On the eleventh day of advent we explore an unresolved puzzle concerning black holes which greatly intrigued Stephen Hawking.
Now we think we know all about black holes, here is another surprise: they are not completely black after all.
Explore a mystery that intrigued Stephen Hawking until the end of his life.
Nothing, not even light, can escape from a black hole. Or can it? Find out about one of Stephen Hawking's most radical results.
A quick tour to some of Hawking's most significant achievements.