   I don't know where else to put this or how (newbie, advice appreciated), but...  Rose, Jack and the Doctor play the tape of Dr Constantine trying to treat Jamie. But there were no tape recorders in Britain in 1941. Tape recording was developed by the Germans in WW2 and not available to the Allies until after the liberation of Luxembourg. A professional like Dr Constantine would have used a transcription disk of some type.http://en.wikipedia.org/wiki/Magnetic_tape_sound_recording   