Is Time Travel possible?
"Well, of course time travel is possible", say the Smug Gits. "Actually, you are time travelling now - you are travelling into the future at the rate of 1 second per second" before their guffaws are silence by a punch to their smug gittery faces.
If Galiffreyan travel were possible, then surely there be some evidence of it, wouldn't there...?
Witness this film from 1926 with some haggard Time(old)Lady Romana on a Chenery Travel OAP chronocoach trip to the past, talking on her mobile phone to the other codgers returning to the good ole days of yore:
Now, before all you start moaning about phone masts and 3g technology not being available in Charlie Chaplin's age - this old baggage is from the FUTURE, where they probably don't need such low-tech methods of telephonic audio transference.
Of course, it could be that Lost Victorian Technology (hidden by the Chiswick Townswomen's Guild when rewriting the history books), and the 20s were rife with valve-ridden Tesla powered phones on his wireless energy transfer network (available since 1893). T-Mobile? Tesla-Mobile!
But we have no such antiquated evidence of steampunkery in our museums, apart from Charles's cabbage computer. Therefore she must've come from the future using a gigawatt of energy from the cock tower!