Time Travel

[TonyM]

I'm always always late for everything but last week I came early? Relativity speaking like.

 

[poh]

Get the bus to Rochdale and hey presto it's 1985

Come to rag central here in the summer and you are back at 1890 every fucking day,I must go as I have left a witch burning and i do love to see the woman crumble at the end,it's always good for a laugh during these long winter nights

 

[Damocles]

Where does he say it can't exist? He clearly states "Backwards time travel is theoretically possible by several different methods using general relativity. " If it's theoretically possible, by definition, it can't "viloate the laws of physics."

It absolutely violates the law of physics.

Firstly we need to understand what this is referring to. The usual reference is to Godel who showed that the field equations in GR would allow something to arrive before it left, in a Universe where all matter is rotating. This is not a Universe that exists which is why it was "theoretically possible" but not "possible".

Others have tried to tie GR into backwards travel using string theory and all of them start with the preface of "imagine a Universe like ours but where you can do X; given these axioms it is possible using GR calculations". Again, all of this is fine but we don't live in a Universe where you can do X which is why backwards time travel is still an impossibility.

 

[marco]

It absolutely violates the law of physics.

Firstly we need to understand what this is referring to. The usual reference is to Godel who showed that the field equations in GR would allow something to arrive before it left, in a Universe where all matter is rotating. This is not a Universe that exists which is why it was "theoretically possible" but not "possible".

Others have tried to tie GR into backwards travel using string theory and all of them start with the preface of "imagine a Universe like ours but where you can do X; given these axioms it is possible using GR calculations". Again, all of this is fine but we don't live in a Universe where you can do X which is why backwards time travel is still an impossibility.

how do you know we cant do x and how do you know that the laws of physics are equal throughout the (our) universe, bottom line to the question is no one knows and that's simply down to humans not having the intelligence to create such a machine to enable this

 

[Hamann Pineapple]

Surely we just have to develop a way of travelling really fast outside the earth's atmosphere. I thought we were working on this anyway in order to reach planets further afield. If you can blitz it to a far off planet and back in say 10 years, by the time you get back it would be, say, 20 years on in earth's time. That's time travel isn't it ?

 

[bluethrunthru]

I think if you buy one of the cars that were made in Northern Ireland with tax payers money, find a friendly but slightly weird but not in a paedo way professor, get a small and slightly shaking man who thinks he can act but in reality all he does is run around like an ex-leper and then invent some y shaped light box then time travel is possible.

Yay !! - FOUR pages before a veiled reference to a flux capacitor - I was getting worried Blues - I was starting to believe it wasn't possible - daft I know but.............

 

[dronefromsector7G]

Surely we just have to develop a way of travelling really fast outside the earth's atmosphere. I thought we were working on this anyway in order to reach planets further afield. If you can blitz it to a far off planet and back in say 10 years, by the time you get back it would be, say, 20 years on in earth's time. That's time travel isn't it ?

I think most are referring to the BTTF type as in arriving at a certain point in history in the same location as you left. There'd have to be an infinite number of time zones though. It's less likely than Phil Jones presenting X Factor.

 

[Chris in London]

I read a fantastic novel years ago about three students who invented a time machine. They went back to the time of the nativity to see if it was true. And guess what? They agreed they needed to land their time machine outside Bethlehem to avoid scaring the locals and ended up scaring the shit out of some shepherds instead who thought they were angels. So there weren't actually three wise men, just three students from California. Gold, frankincense and myrrh were actually some change, an inhaler and something else I can't remember.

It was a really interesting premise. I read it aeons ago and can't remember what it was called.

 

[Jim Tolmie's Underpants]

Where does he say it can't exist? He clearly states "Backwards time travel is theoretically possible by several different methods using general relativity. " If it's theoretically possible, by definition, it can't "viloate the laws of physics."

It absolutely violates the law of physics.

No it doesn't. I don't know why you keep disagreeing with scientists who know a lot more about this than you do.

The general theory of relativity allows the so-called closed time-like curves which allow backwards time travel, at least in principle.

http://www.sciencechannel.com/tv-shows/through-the-wormhole/could-we-go-back-in-time-2/

 

[Damocles]

No it doesn't. I don't know why you keep disagreeing with scientists who know a lot more about this than you do.

The general theory of relativity allows the so-called closed time-like curves which allow backwards time travel, at least in principle.

http://www.sciencechannel.com/tv-shows/through-the-wormhole/could-we-go-back-in-time-2/

Because you're misunderstand what they're saying and taking it mean something else. I'm in total agreement with them because I know the math that they're doing, it's your interpretation of what they're saying that I'm disagreeing with. CTCs are a consequence of GR in specific circumstances. None of these circumstances exist.