HIRO NAKAMURA in the TV show Heroes has the enviable knack of travelling through time and space. For the rest of us, it’s not so easy – unless we can find a “naked” black hole. Such bodies could act not only as a “cosmic time machine”, but might be responsible for the gamma-ray bursts often seen from Earth, which could be signs of time travellers coming back from the future.
This cosmic time-travel scheme using naked black holes was dreamed up in the 1970s by Fernando de Felice at the University of Padua in Italy. His idea, which he has now…



