Time Travel

[Bazile]

If it became possible , would it be more probable to travel back in time because it has already happened , as opposed to travel to the future , which has not yet happened

[birdie1971]

Considering that we all exist a rotating ball of rock that is orbiting a rotating ball of boiling hot plasma which is situated in an outer-spiral arm of a galaxy we call the Milky Way (see link), which is itself moving relative to every other object in a universe that no one truly understands the physics of then I think it's safe to say that time travel is impossible. For if it were possible, to travel backwards or forwards in time would require you to know in advance precisely (by which I mean to the literal Planck length) where each moving piece of the universe was or will be at any given specific time. If you went back in time just one second you'd find yourself floating in deep space due to the fact that everything has moved relative to you. In order to time travel, you have to be able to predict – with an accuracy that can barely be imagined – where every object in the universe either will be or has been to the literal n'th degree. The slightest error will have you drifting in the void or mangled by matter. You cannot just travel through time. You must travel through space and time in order to 'time travel'. And that requires ultimate knowledge, which, suffice to say, we don't have and will never have.

[jim360]

Honestly I'm surprised birdie, I thought you'd be less willing to rule it out. I wasn't going to post in this because, although I believe time travel in the sense it's usually meant is and always will be impossible, I didn't really think it was a decidable question, scientifically. Eg one plausible means of travelling through time (and space) would be a wormhole, which is kind of theoretically sort of possible, maybe, in Relativity? Or locally near rotating black holes there is an effect which is similar enough to count as time travel.

If another regular AB commentator hadn't exiled herself from AB's science board then Naomi would have been along to say something along the lines of her not knowing and nor does anybody else, and I wouldn't really be able to disagree with that. We've made a lot of progress in understanding the nature of time in the last century or so, but not enough, I would suggest, to make any kind of definitive statement that time travel must be impossible. Implausible and unlikely, certainly.

[birdie1971]

Jim - “...then Naomi would have been along to say something along the lines of her not knowing and nor does anybody else, and I wouldn't really be able to disagree with that...”.


And neither would I. My above opinion about having to know literally everything about the universe in order to travel through both space and time (which is what time travel requires) is just that – my opinion. I don't actually know. No one does. But seeing as though everything is moving relative to everything else (which is something we do know for a fact) then logically time travel cannot be possible due to Schrödinger's Uncertainty Principle.

[jim360]

Heisenberg's*, although I'm not sure that it quite applies in the way you mean. No argument that arbitrary time travel is impossible as you describe it, though: the possible work-arounds that have been proposed tend to be exotic or extreme in ways that don't undermine the main point you're making.

It's nice to find something on which we more or less agree for a change, though.

[birdie1971]

Jim

Heisenberg! Aargh!
Thank you. Good catch.

And yes. It's nice to find common ground.

[Arksided]

Being there done that, and we're still Muppets

[birdie1971]

Jim

“... the possible work-arounds that have been proposed tend to be exotic or extreme in ways that don't undermine the main point you're making.”

I would love time travel to be possible. I'm a sci-fi aficionado. Pretty much read everything Asimov has ever written. Love Arthur C Clarke. Was directed to read Brian Aldiss', 'Hot House' a few years ago and it blew my mind. As did Alfred Bester's “The Stars My Destination”.

I think we're probably far more similar than we are different. I suspect we'd get on in real life. Correctly socially distanced of course.

;-)

[Mozz71]

I'd go back in time, tell Dom Cummings npt to break isolation to spare us all having to put up with AB being so effing self-righteous for the forseeable future.

[ToraToraTora]

ken "TTT, have you never considered that time travel is possible but exclusive only to bookmakers. " - why set up a business shop, when you can go into any bookies and put 10p on the ITV 7 at often at you like? Nope, as originally state time travel will never exist.

[ToraToraTora]

ken "TTT, have you never considered that time travel is possible but exclusive only to bookmakers. " - why set up a business when you can go into any bookies and put 10p on the ITV 7 as often as you like? Nope, as originally stated time travel will never exist.

[CrapAtCryptics]

Never Say Never

[ToraToraTora]

i will say never. Can you not see the reasoning? There are gambling establishments in existence. They rule out time travel, for ever.

[Ken4155]

Didn't realise that this was in science at first, and must therefore apologise - for my flippancy in my tongue-in-cheek to-ing and fro-ing with TTT - to those who have taken the question ultra seriously. My bad, as they say.

[Bazile]

Who's to say what will be possible in the future .

It might seem improbable now.
Let's reconvene in a thousand years or so time ,to discus this post

[Chinajan]

Professor Stephen Hawking held a welcome party for time travellers in 2009. No one turned up. He had been hoping that 'a future Miss Universe' would attend.

[jno]

it was a mistake sending out the invitations in 1732, Chinajan, diaries hadn't been invested and people forgot the date..

[flobadob]

The problem with "time" travel is that if you simply travel back through time from your current location, then you would end up stranded and of course dead, somewhere in deep space.

The reason for this is that, for example, if you travelled back in time to last week, earth was millions and millions of miles from its current position.

Therefore to make time travel to a certain time and place work, you would need to travel through both time and space, plotting the course of earth through the vast void of interstellar space.

One wrong calculation and you wind up dead.

[fiction-factory]

I asked myself the same question next week.

[flobadob]

I think the answer is you can't travel to the past, but there is some hypothesis that you can travel to the future, but only in terms of, for example, you leaving earth for 3 months (at the speed of light) but when you return, 3 months and 1 day have elapsed for everyone who remained on earth.

[JimF]

Ah, but that's not time travel - that's just relativity!