http://www.youtube.com/watch?v=fEcHp54_yG4&feature=player_embedded
BBC America has released a clip from The Science Of Doctor Who , a one-hour special will air in the States later today. In this clip Steven Moffat and knowledgeable boffins debate the possibility of time travel using Einstein's Special Theory of Relativity and wormholes...
Read the SFX analysis of the Doctor Who series 7 trailer
