Saturday, 23 November 2013

can daleks travel faster than the speed of light?

Saturday night at the BFI
We were at the BFI on Saturday evening and it turned out there was a bit of a bash on for Doctor Who.

A couple of daleks managed to gate-crash and it made me think again about the time traveller dilemma. It would make sense to publicise a set date for time travellers to convene and a globally publicised Doctor Who fest could be one such moment. No actual time travellers were present though, unless they forgot to mention it.

It remands me also of the telly programme about Doctor Who physics shown a few days ago. It illustrated relativity, spacetime curvature and the effects at the edge of a black hole when observing the event horizon.

Some of it has great mathematics, but I can't help thinking there's a whiff of phlogiston about it. Phlogiston was the stuff supposed to be consumed by things that burned. Until a better theory came along.

So my dilemma is that clever people say things can't move faster than the speed of light. OK, so how can the earth's position relative to the sun by gravity be twenty arc seconds (8.3 minutes) ahead of its observed position? That would mean that gravity was somehow working faster than the speed of light.

Or, how could a black hole, which consumes all light, be able to have a gravitational pull? The gravity would have to be able to escape, whilst the light couldn't. Doesn't this mean it needs to travel faster than light?

Someone will say gravity is a wave, or that there's a yet to be discovered particle called a graviton. But whatever the explanations are, it still seems to me that there's some black holes in the theory.

How else would the daleks have been able to get in the bar?

3 comments:

Doris said...

Those pesky daleks manage to get everywhere!

As for some of the theories out there I really do wonder. When one stands back and looks at some of them they seem flaky and catch all in some sort of sciency haze that one is supposed to agree with in awe. And if you don't agree then one obviously does not understand.

Sounds like you had an interesting evening.

rashbre said...

Doris Yes, there's clearly real science with lots of whizzo formulas, but occasionally there are bits that seem to rely on faith rather than objective measurement. I shall have to ask the next scientist I meet why gravity can't travel faster than light.

Doris said...

But Rashbre, are you asking the right question? Remembering a certain answer of 42 and the search for the ultimate question!