Dr Who - just weeks away.

[TimberWolf]

<Catherine Tate>
But it is though.
</Catherine Tate>

Spacetime can be bent - that's the whole point of General Relativity. There are paths around very dense spinning objects (like a few members here), that end at a point in spacetime before the beginning. Also, there's no particular reason why spacetime can't be bent to provide a navigable route back in time. (It isn't possible, so far as current scientific understanding is concerned, to go back to a time before the time machine or path was created ).

Not that it matters one jot, since the time-travel aspect is merely a literary device in order to tell stories.

You sound as you've been reading popular science magazines. Causality is at the heart of relativity and while backward time travel may be coaxed out of it in realms where the equations blow up, no-one serious believes it's possible outside the realms of bad science fiction.

[NotAllThere]

Indeed. Didn't CBBC horrible histories recently win an adult award?

Then they tried to shift it to primetime, having Stephen Fry, instead of the rat. Total crap. The rat is definitely better.

I'm Sorry I've Got No Head is worth watching as well - kind of bastard offspring of the Fast Show. "She's a witch", "A thousand pounds?",...

[NotAllThere]

You sound as you've been reading popular science magazines. ....

I had to put it in terms that the punters here would understand. Thing is, that wormholes and twisted space are valid solutions to Einstein's field equations. Time travel does have consequences for causality, and scientists would prefer to keep it. But there's nothing fundemental that prevents causality being violated. At the quantum level causality is problematic. Perhaps a unification of general relativity and QM will result in a proof that causality is preserved, and time travel is impossible.

[d000hg]

Dr Who jumped the shark many, many series ago.

Jumping the shark (oh jeez another tired cliche meme) is THE WHOLE POINT of Dr. Who.

You sound as you've been reading popular science magazines. Causality is at the heart of relativity and while backward time travel may be coaxed out of it in realms where the equations blow up, no-one serious believes it's possible outside the realms of bad science fiction.

a)Classing any Sci Fi which includes TT as bad is silly for a start
b)Yes of course they do. Not many but "no-one" is really not something a scientist should claim

And before we get too serious...

[Gentile]

I quite like Doctor Who (just about the only telly I've watched since about 2002), but they've really been messing it around the schedules for the past year or two, so I find I miss it rather than chase it about. I'll catch up on iPlayer at some point, I'm sure.

[TimberWolf]

Jumping the shark (oh jeez another tired cliche meme) is THE WHOLE POINT of Dr. Who.

a)Classing any Sci Fi which includes TT as bad is silly for a start
b)Yes of course they do. Not many but "no-one" is really not something a scientist should claim

I said "no-one serious", which is a considerably smaller than the set of "no-one". No physical process is irreversible as far as I know, but nevertheless for a macroscopic object to travel backwards in time, while the rest of the universe continues to obey the expected rules of causality and direction of increased entropy, the arrow of time, will require some book keeping to pull off. Take a collision of just two atoms for example. To get back to the pre-collision state would require all the photons emitted in random directions at the speed of light at the time of collision, and influenced locally by the rest of the universe immediately thereafter, to come back with the same energy and momentum as immediately at the collision. Bring those atoms together without the book-keeping intact and you'd need to explain how the universe is not to be filled with paradoxes. Those photons did stuff with the rest of the universe. Are you going to roll back the rest of the universe? A complete roll back would be possible IMO, as well as other possibilities with "many worlds theories", but that's not what's being discussed here, we're discussing the feasibility of Dr Who physics. Granted things are a little different at the quantum level, where time and space and many familiar things have little meaning, but it's the macroscopic world we inhabit and where the interest lies.

Perhaps you'd like to name someone serious who regards travelling backwards in time, for a macroscopic object, as feasible, or explain how you think it might work bearing in mind what I've said above.

[NotAllThere]

The physics is totally irrelevant, since Dr Who is an adventure story and a bit of a laugh. (Personally, I think time travel is impossible, and will maybe one day be shown to be, but what does that matter?) To write Dr Who off simply because it has time travel in it is a bit daft though. Here's a few fairly heavy duty sci-fi authors who've written stories including time travel.

Poul Anderson
Isaac Asimov (thiotimoline! )
Robert Forward
Harry Harrison
Larry Niven
Heinlein
Kornbluth (Little black bag)
Harlan Ellison
Michael Moorcock
Julian May
Bob Shaw
Clifford Simak

That's just off the top of my head. I've definitely missed a few...

Hey, how about all of these!

[AlfredJPruffock]

The one question that Ive been running away from all these Years ..

Doctor - Who ?

Doctor - Who ??

Time Travel - dont make me laugh altough in an infinite Time Zone everything will happen also Time is not what you think it is ...

So there.

Meet the new Doc - same as the old Doc.

PS I did reecently work (in an IT capacity) on a Cosmic Time Travel project - True or False ?

[darrenb]

You're talking bollocks. The storylines have been excellent.

Except the ones with dinosaurs.

[MarillionFan]

Except the ones with dinosaurs.

WTF! It was damn scary!