The Official Time Travel Thread

[Shivan]

Many theories exist on the subject of Time Travel and whether or not it is feasible/possible. There are some who are fanatical while others are skeptical.

And more than likely the majority of us either a) Never care enough to give it deep enough thought or b) Believe it to be unfathomable and impossible.

I've been in many discussions on this matter, and I'll be honest I do not know much about it. But this seems like a good place to start a healthy discussion for it.

I'll start off with a basic question/statement to get this thread off the ground.

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Many argue that time travel isn't possible for the sole reason that time isn't a force which actually exists. Unlike gravity, time is just something we humans keep up with by assigning hours to the days and days to the week.

Universally speaking, time may not even exist. There may not be a beginning nor an end.

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Discuss!

[Matt G]

I'd respond to that with the theory(not sure who to give credit to but I know the basics) that Matt G's bedroom in Teddington, Greater London UK 7pm 8th April 2005 is a different location to Matt G's bedroom in Teddington 6:59pm 8th April 2005 and Matt G's bedroom in Teddington 7:01pm 8th April 2005.

Therefore, time travel just involves travelling between locations that are extra hard to get at.

Assuming that, I also think that travelling back in time is like playing a computer game. Let's say I travel back to Teddington on a Sunday evening in Aprill 1995. Everyone who 'belongs' in April 1995 is preprogrammed to behave in a particular way on that particular evening by Time. My presence there on it's own won't change anyone who belongs in April 1995's Sunday evening. They'll just be watching the Antiques Roadshow, eating dinner, walking down the street, chilling out...whatever.

Once they've lived that day once, without a time machine, they can't do anything about it.

However if you shoot a bad guy in a computer game and he dies, he's no longer in your way. The scenario has changed.

If I decided while in April 1995 that I fancied a pizza and I'd brought enough cash back with me, then OK, I find find myself a pizza place in the area of Teddington April 1995(even if I had to get a bus to Kingston to eat at the Pizza Hut there). However in doing so I'd change the scenario in various ways.

There would either be less space on the bus to Kingston or someone would have to wait longer on the bus than they had done previously.

Someone might get turned away from Pizza Hut because I'm taking up a table which they'd have taken up previously.

And the Pizza Hut would have had to order up a fresh batch of pizza bases, sauce, cheese and pepperoni slightly sooner than they'd have done previously.

Shooting the bad guy won't neccersarily end the game, but it changes the scenario.

2005 me getting a bus to Kingston and visiting Pizza Hut for a pepperoni pizza in April 1995 won't end the world(unless one of the people affected got really annoyed and decided to blow up the world!)

[Anubis69]

Can't remember where, but i remember reading that if travelling faster than the speed of light is possible then going back in time also is. Can't remember the specifics either, but since i hope, and believe, that we can go faster than light i'll assume it's true!!

The way i see it, is there's two kinds of time travel. That everything is meant to happen, going back in time is included in that, like in the season 2 episode "1969" where SG-1 went back in time and hammond helped them, then when they got back they realised that hammond knew all along. An interesting point and brings in the idea that everything happens for a reason etc etc.

The second is that time is linear and that if someone goes back they alter life as they know it. obvious examples include back to the future and where i think SG-1 contradicted themselves on it, "mobius", "2010" and "2001". Also my understanding is that Star Trek works the same way as this.

[Supreme Commander Gav]

My first post, so go easy! I'll add my two 'cents' to 'coin' a phrase. Heh.

Anyway, Lets look at a number of facts:

1) It is shown the faster you are the more time slows down.

Yes it 'slows down' but at what point does it turn backwards on itself? Some people say if we go faster than the speed of light. Personally I believe this wouldn't reverse anything it would bring time to a complete standstill or I could be wrong - Probably am.

2) Multiple Universes.

I can appreciate that if there are multiple dimensions out there then it may be possible to travel to another one of these, but I have no doubt that you could never travel back to your own dimension because then we start getting the grandfather paradox and I don't think we want to go there!

Matt G, refering to your post I believe that if you were in your own universe then doing what you suggested could be disastourous for your self. Say someone in your pizza hut got pissed cause they'd made one to many pepperoni pizza's and you get mugged. This is just an obscure example mind you, this Could lead to a series of events in your life which would never take you through the time machine and then we start getting into time paradoxes again

Anubis, I can see the reasoning behind your two choices of different time travel, obviously they inter connect with each other, I can't help wondering the following though. Why did SG-1 have to go back in time anyway? Technically its all in the past and everything has allready been done with either means that every single dimension in the entire universe would have to go back in time, and what happens if one fails? Then were pretty buggered!

As I stated before I believe time travel one day will be possible in one direction only - the future - by slowing down time relative to the undertakee, hope I've provided some in sight too my way of thought

[Matt G]

If the 2005 version of me got mugged in 1995 then it wouldn't affect my personal history up till 2005. If someone in the Pizza Hut in '95 got pissed off because he wasn't able to get a seat or something and through their anger bumped into my 1995 self a few days later and mugged him then yes my personal history would get affected but it shouldn't affect my journey back through time. If the guy killed my 1995 self...then we'd be talking paradoxes yeah.

But unless that or some other event happens that prevents the possibility of me travelling back from 2005 to 1995 there would be no paradox.

[Shivan]

My first post, so go easy! I'll add my two 'cents' to 'coin' a phrase. Heh.

Anyway, Lets look at a number of facts:

1) It is shown the faster you are the more time slows down.

Yes it 'slows down' but at what point does it turn backwards on itself? Some people say if we go faster than the speed of light. Personally I believe this wouldn't reverse anything it would bring time to a complete standstill or I could be wrong - Probably am.

I do not think that traveling faster than the speed of light slows down time at all. You're just moving fast and can cover less space in a smaller amount of time.

[Supreme Thor]

If the 2005 version of me got mugged in 1995 then it wouldn't affect my personal history up till 2005. If someone in the Pizza Hut in '95 got pissed off because he wasn't able to get a seat or something and through their anger bumped into my 1995 self a few days later and mugged him then yes my personal history would get affected but it shouldn't affect my journey back through time. If the guy killed my 1995 self...then we'd be talking paradoxes yeah.

But unless that or some other event happens that prevents the possibility of me travelling back from 2005 to 1995 there would be no paradox.

Actually, Matt, there have been stories about the theories of time travel (ex: "The Sound of Thunder", a short story). The theory in most of these stories (and, I believe, including "Moebius") is that the smallest change in the past, due to the forbidden presence of a time traveler, can change the course of the entire future. I mean, look what happened with SG-1: all they did was try and steal a ZPM, a simple task, right? Well, that simple task ended up in the deaths of more than half of SG-1, and the total alteration of the course of the future.

So, my belief:

I don't really believe time travel is possible at our current level of technology. I think at some point, somebody with the right idea will achieve it. But, even if we do manage to somehow achieve time travel, I think it's a science that man was not meant to mess with.

[Shivan]

Actually, Matt, there have been stories about the theories of time travel (ex: "The Sound of Thunder", a short story). The theory in most of these stories (and, I believe, including "Moebius") is that the smallest change in the past, due to the forbidden presence of a time traveler, can change the course of the entire future. I mean, look what happened with SG-1: all they did was try and steal a ZPM, a simple task, right? Well, that simple task ended up in the deaths of more than half of SG-1, and the total alteration of the course of the future.

So, my belief:

I don't really believe time travel is possible at our current level of technology. I think at some point, somebody with the right idea will achieve it. But, even if we do manage to somehow achieve time travel, I think it's a science that man was not meant to mess with.

I have a few things I'd like to say-

If Time Travel isn't possible, but alternate universes DO exist and we find a way to travel between these realities than essentially we can find realities that are slightly different compared to when the Universe began. A good example of this is in the Sliders episode. It's not really going into the past, it's going into an alternate realm where the present time is the past compared to our realm.

^I don't know if that makes any sense or not, lol.

But anyways, we wouldn't be changing much there because the future still isn't certain and hasn't already happened. Though if we achieve Time Travel then just the act of using the machine to go back and time is dangerous. Especially if someone saw it. The slightest difference CAN change the whole future.

[TechnoWraith]

Well, according to Einstein's Theory of Relativity, the faster you go, the slower time moves. (I think that's it).

So theoretically, if you travel fast enough, you'll bring time to a stand still. So if you travel even faster than the speed required to bring time to a standstill, will time start going backwards? Then again, if you're moving so fast that time stands still, there's no way to tell how fast you're going (because you're measuring distance over time, and since time is stopped, you won't know).

Strange as it sounds, it's a thought that came into my head while reading this thread.

[Shivan]

Well, according to Einstein's Theory of Relativity, the faster you go, the slower time moves. (I think that's it).

So theoretically, if you travel fast enough, you'll bring time to a stand still. So if you travel even faster than the speed required to bring time to a standstill, will time start going backwards? Then again, if you're moving so fast that time stands still, there's no way to tell how fast you're going (because you're measuring distance over time, and since time is stopped, you won't know).

Strange as it sounds, it's a thought that came into my head while reading this thread.

I understand what is being said here. Think of it kind of like when Superman is running faster than the speed of light, he is going so fast that everything around him is going slow from his perspective. My question is, does our brain have the ability to process what we would see if WE were traveling at that speed.

I think time doesn't slow down, it just looks like it because you're moving over more distance much much quicker.

[Jarnin]

Since this is the science and technology section of the forums, I figured I'd provide some links to information which is related to this topic:

Time travel
Types of time travel

Einstein's theory of relativity
Time dilation
Wormholes

When it comes to what types of time travel I think nature allows, I'd have to go with:

The time line is consistent and can never be changed.
Any event that appears to have changed a time line has instead created a new one.

With those guidelines, anybody that travels back to the past automatically creates an alternate timeline where they can do whatever they want without changing anything from their 'home timeline'.
I could travel back to the past, accidentally kill my grandfather before he fathered my father. My grandfather, and my father would still exist in my home timeline.
This set of rules would explain why there hasn't been any evidence from the future in the real world. Since time machines don't exist yet in our current timeline, that would mean it's either impossible to build one, or they don't end up here when they travel back in time.

The only drawback to this set of rules is that once you travel back in time, you can never travel back to your home time line. You'd basically be stuck in alternate timelines for the rest of your life. You'd cease to exist one day in your home timeline, never to be seen again.

[lionel_pendergast_rocks]

i find that time travel is a very fascinating subject, and it's really confusing at times. for instance, while watching moebius, i was sitting there, trying to piece together all the events and see how they fit together. but even in its coolness, i don't really think it will ever be possible. it's an amazing subject, and i'm glad someone started a thread about it. but hey, it's cool in stargate, so i'm good with that.

[Bacardi]

my opinion of time travel, directly linked to what we see on sg1 and atlantis, is that if time exists, and is effectively on a line ("timeline"), if it were possible to travel back along the timeline it would create a branch parallel to the previous timeline, so rather than being able to go back and change something, it would be like making a copy of time and deleting everything back to the point at which you travel. my opinion would be that one could not travel back and forth in one's own timeline as each trip in time would create alternate timelines.

[Anubis69]

The time line is consistent and can never be changed. Any event that appears to have changed a time line has instead created a new one.

yeah, i like that!!! it's a bit like that episode of charmed where cole turns back time to stop the charmed ones meeting paige, whether he created an alternate universe or actually altered time, i can't remember but it is similar.

Oh yeah, and Shivan, thanks for starting this thread! after posting in it the other night, i brought it up when i was talking to some friends. it got us debating for ages!

One point that did come up, one guy said that if we went back in time, just being there would alter it, which i disagree with. i'd say the traveller would have to interact with the surroundings or someone (eg. like picking a flower and preventing someone from picking this flower later in life and hence someone not receiving it and a relationship failing), and not just being there. his reply was....."you could be corroding the ground by standing on it"!! even in an extreme case i could understand standing on grass, but i don't think one other person standing on concrete changing the whole history.

[Shivan]

yeah, i like that!!! it's a bit like that episode of charmed where cole turns back time to stop the charmed ones meeting paige, whether he created an alternate universe or actually altered time, i can't remember but it is similar.

Oh yeah, and Shivan, thanks for starting this thread! after posting in it the other night, i brought it up when i was talking to some friends. it got us debating for ages!

One point that did come up, one guy said that if we went back in time, just being there would alter it, which i disagree with. i'd say the traveller would have to interact with the surroundings or someone (eg. like picking a flower and preventing someone from picking this flower later in life and hence someone not receiving it and a relationship failing), and not just being there. his reply was....."you could be corroding the ground by standing on it"!! even in an extreme case i could understand standing on grass, but i don't think one other person standing on concrete changing the whole history.

Well if you even want to be more technical doing absolutely nothing but being there could also change the timeline thereotically. Mainly because someone could glance your way and study you for two-three seconds and that changes their whole life, which would cause a MAJOR change in history. Just being there changes everything, because you were never there to look at before.

I am fond of the theory in which when you go into the past timeline you create a new timeline instead, but your timeline still exists. But the person above said you couldn't ever get back to your own timeline, I do not see why you couldn't? You never did anything to change your timeline, because this theory prevents that by creating the new timeline. Say your friend saw you get in the machine and POOF be gone. Nothing has changed for your friend, and you are still gone and missing. You could come back a day later and explain what happened on your trip.

I don't know really, I want to know what would really happen if we did ever achieve the possibility to travel through time.