Occasionally you'll watch a programme on TV and it will just blow you away. Like a diamond floating round in a sea of trash, just such a programme came on last night, Prof. Brian Cox's Lecture about the Science of Dr. Who.
What I expected were explanations about the Doctor's gimmicks like his Sonic Screwdriver and K9 robodog. What we got was hour long opus on the possibility of time travel with the occasional side-step into electricity and magnetism. In short, it was brilliant!
Asking the basic question whether the good Doctor could actually travel through time in a Tardis, the impossibly young Prof Cox set about explaining the rudiments of Einsteinian Relativity and the peculiar nature of space-time.
For me the most illuminating feature of his talk was how time is categorised as light cones both in the past and future. Our own light trail, each and every one of us, is called a World Line if I remember rightly. Our World Line, from birth to death, travels through space-time but is bounded by the speed of light, which nothing can overtake. It reminded me of the spirit snakes following the cast of the movie Donnie Darko! Prf. Cox drew it something like this [I've added the colours]:
In order to travel in time like Doctor Who we would have to find a way to bend space-time so that our Future light cone curved round our Past Light Cone and in effect connected up at its base, allowing you or me to walk from our future into our past [reminds me of this blog!]
Prof. Cox explained that unless we indeed actually invent a Tardis, which could bend space-time like a toilet roll, we are alas, trapped in our own futures and the past is closed firmly shut.
However, places do exist in the Universe that ignore space-time and the speed of light, namely Black Holes. If we were able to approach a Black Hole our World Line would bend towards it's rim, the Event Horizon. If we pushed on into the Singularity at the Hole's heart we would enter a realm beyond our current understanding where light is eaten and time is void. What passers-by would see would be one final eternal image of ourselves as we loitered on the threshold, one final snapshot following the rules. Apparently Science describes the next stage as spaghettification as our bodies would be stretched to infinity by the new physics of the Singularity!
It was really excellent TV and he's a gifted presenter. If you haven't seen Prof Cox then its a treat. Prepare to have your mind blown! Did anyone else see it and does this type of stuff interest you readers?
