Very hypothetical question on time travel

SuprSi

Hypothetically, if time travel was a possibility and someone travelled back in time, changing something in my past that meant I didn't exist in the future, what would happen to me now in the present?

Would a separate timeline be developed without me, almost like a different universe? Or would I just disappear, along with all of the memories of me?

I've read that time travel into the future has not been dismissed as impossible but this is just something that came into my head after watching Star Trek First Contact last night (great movie!).

locum-motion

Well, there really is no actual knowledge about what might happen, or at least not as far as I know! We only really have what Hollywood/science fiction tells us.

Different movies have handled it differently: in Back to the Future 2, they go down the 'alternative timeline' route ie. Marty buys an Almanac from 2015, old Biff steals it and gives it to young Biff in 1955. When Marty gets back to 1985, he finds it very different from what he remembers because Biff has been a very successful gambler for 30 years on that timeline.

On the other hand, Looper goes down the 'obliterated from history' route

At the end of the movie when Joe (played by Bruce Willis) is about to kill the kid, Joe (played by Joseph Gordon Levitt) prevents him from doing so by the simple method of blowing his own head off, thereby erasing his older self (Bruce Willis) from existence.

locum-motion

As I was typing that, I remembered that the 1st BttF movie also used the 'obliterated from history' method: Marty inadvertently prevents his parents meeting in 1955. He and his siblings then slowly start becoming erased from history, as shown by them slowly vanishing from Marty's 1985 photo of them. Their vanishing corrects itself when Marty 'fixes' history by making sure that his parents do actually meet and fall in love.

locum-motion

It's best not to think too deeply upon this topic. It could really melt your brain!

Maximus Alexander

It's possible that if you could travel back in time you simply wouldn't be able to change anything.

For example, if you tried to kill your own parents before you were born something would always go wrong. Because you can't have killed them, otherwise you wouldn't be there to do it.

mathepac

[QUOTE=Maximus Alexander;81922343... Because you can't have killed them, otherwise you wouldn't be there to do it.[/QUOTE]Of course you could.

In this very hypothetical scenario, as distinct from a simply hypothetical one, you wold immediately jump to a universe that parallels the one you have travelled to. These parallel universes exist for everyone and play out various scenarios relating to that person; e.g. parent's don't meet, different parents, different gender, etc.

Choosing the precise time to jump universes, is very critical as if you mis-time the jump you can be very dead, in the present, which means all the parallel universes must realign themselves which uses a lot of electricity.

djpbarry

locum-motion wrote: »

As I was typing that, I remembered that the 1st BttF movie also used the 'obliterated from history' method: Marty inadvertently prevents his parents meeting in 1955. He and his siblings then slowly start becoming erased from history, as shown by them slowly vanishing from Marty's 1985 photo of them. Their vanishing corrects itself when Marty 'fixes' history by making sure that his parents do actually meet and fall in love...

...and Marty develops Parkinson's.

Don't go ****ing with the timeline kids.

Victor

mathepac wrote: »

Of course you could.

In this very hypothetical scenario, as distinct from a simply hypothetical one, you wold immediately jump to a universe that parallels the one you have travelled to. These parallel universes exist for everyone and play out various scenarios relating to that person; e.g. parent's don't meet, different parents, different gender, etc.

Choosing the precise time to jump universes, is very critical as if you mis-time the jump you can be very dead, in the present, which means all the parallel universes must realign themselves which uses a lot of electricity.

\o/ Yay, infinite universes for everyone in the audience. :rolleyes:

The_Gatsby

http://tinyurl.com/d8e8kzc

This should explain everything

SuprSi

Some very interesting contributions here. I think locum-motion said it best that it's not a good idea to think too long about it. I start to struggle when thinking about the whole multiverse thing and infinite timelines, etc.

Morbert

SuprSi wrote: »

I've read that time travel into the future has not been dismissed as impossible but this is just something that came into my head after watching Star Trek First Contact last night (great movie!).

Time travel into the future is very much possible. All you have to build a ship that travels fast. We have even done it with clocks on a plane, sending them a fraction of a second into the future. Of course, a fraction of a second isn't very exciting, given that the time of the flight is several hours, but the principle is the same. Spend a few hours in a fast enough plane, and you could travel years into the future.

karl_m

Morbert wrote: »

Time travel into the future is very much possible. All you have to build a ship that travels fast. We have even done it with clocks on a plane, sending them a fraction of a second into the future. Of course, a fraction of a second isn't very exciting, given that the time of the flight is several hours, but the principle is the same. Spend a few hours in a fast enough plane, and you could travel years into the future.

That essentially works but you not aging as fast as the rest of people right? as in everyone else would be a year older but you only what feels like a month iyouwent faster/close to the speed of light right?

Morbert

karl_m wrote: »

That essentially works but you not aging as fast as the rest of people right? as in everyone else would be a year older but you only what feels like a month iyouwent faster/close to the speed of light right?

Yes.

karl_m

Morbert wrote: »

Yes.

Thank you.

Zombrex

Two words for you

Red. Matter.

That should explain everything.

Capt'n Midnight

Zombrex wrote: »

Two words for you

Red. Matter.

That should explain everything.

Except that this is a science forum not a technobabble one.

Zombrex

Capt'n Midnight wrote: »

Except that this is a science forum not a technobabble one.

Science! Bah! Next you will be saying tachyons don't explain inverse temporal dilations of the sub-space time matrix. :cool:

Capt'n Midnight

Zombrex wrote: »

Science! Bah! Next you will be saying tachyons don't explain inverse temporal dilations of the sub-space time matrix.

reverse the polarity of the neutron flow

Oddly enough this is technically possible since neutrons have a magnetic moment.

Zillah

I like the new Star Trek way of doing things where you make a new universe the instant you change anything at all (the instant you arrive, atoms are displaced). That way, if you, say, shoot Hitler's grandfather, you've created a new universe with no Hitler, but your old universe is out there still, and you vanished from it.

beardedmaster

All this talk of going back in time to kill Hitler makes me want to play Red Alert..

Capt'n Midnight

beardedmaster wrote: »

All this talk of going back in time to kill Hitler makes me want to play Red Alert..