Hi all. I'm not up to speed on any actual research on this topic but it seems to me that as soon as a person uses a time machine to travel back in time they would be in an unescapable double loop (parallel reality). in one time line the person in question uses the time machine, goes back to a past event and either tries to help themselves or loved ones change things thereby changing their own circumstances and most likely not using the time machine at the future point, and in the other time line, going back and merely observing until such a point as the past version uses the TT and it all starts again. What am I missing here that explains the way around this?
Unescapable loop effects
- Thread starter Malagus
- Start date
vodkafan
Temporal Navigator
I don't necessarily see it is a double loop? The first time line you mention is basically the Grandfather Paradox; yep you pretty much nailed that. There may not be a way around it; that's why it is a paradox.
The other timeline, where you just go back and change nothing, just observe, is actually permitted in some physics solutions. Because you are not creating any paradoxes. (apart from the fact you shouldn't be there I guess) But you have your time traveller hanging around till he comes back to his original time when he left. Why? Can't he stay for a week and then travel forward again?
Some solutions do state that as soon as you go back in time , then you have already made a huge change, you have already changed the future and so if you did try to return to your own future it would not be there; you are in an alternate future. That ties in with Quantum Theory's many worlds idea. That was sort of the idea of that TV series Quantum Leap- he could keep jumping but he could never get to where he came from.
There are many other ideas too. You pick the one you like the best ! Nice to talk with you.
The other timeline, where you just go back and change nothing, just observe, is actually permitted in some physics solutions. Because you are not creating any paradoxes. (apart from the fact you shouldn't be there I guess) But you have your time traveller hanging around till he comes back to his original time when he left. Why? Can't he stay for a week and then travel forward again?
Some solutions do state that as soon as you go back in time , then you have already made a huge change, you have already changed the future and so if you did try to return to your own future it would not be there; you are in an alternate future. That ties in with Quantum Theory's many worlds idea. That was sort of the idea of that TV series Quantum Leap- he could keep jumping but he could never get to where he came from.
There are many other ideas too. You pick the one you like the best ! Nice to talk with you.
Syzygy
Quantum Scribe
Greetings, Malagus.
It is not so much the introduction of a time machine
but its intended purpose that is problematical. Yours
is fundamentally a question of causality. Causality is
complicated by interpretations of quantum physics.
There seem to be two distinct schools of thought on
the subject where one upholds causal order and the
other is left to reconcile chaos.
Hi Vodkafan. The reason I figure he will hang around until such point as his past self travels back again, thereby completing and resetting the loop, is because I was using the assumption that the means of time travel are yet to be invented in the past timeline. unless of course we're talking about a portable device. But my personal opinion is that if (when?) we ever do master time travel it will require huge amounts of energy that wouldn't exactly fit in your pocket
vodkafan
Temporal Navigator
Hi Malagus,
That's good thinking. I am of exactly the same opinion. In fact in the story I am writing it is not a portable device either.
OK though lets think about this; it doesn't actually make a loop per se.. What it does do is create an endless number of bored time travellers. We will use round figures to make it easier.
Say your man Smith gets in the time machine when he is 50 years old. In this version, you said he just goes to observe so as not to make a paradox. He goes back 20 years to view the family crisis or whatever it is. But the 30 year old version of himself is already there.(We will call him Smith 2) So now there are 2 Smiths in the same time. They cannot meet because that might make younger Smith 2 do something different and change things. So the time travelling Smith has to wait 20 years. He sees himself get into the time machine that he himself got into and disappear. Only now he is 70 years old. he can now without fear of changing anything resume his normal life . But to someone who might see him the next day, Smith has just aged 20 years overnight.
If he is still alive when he is 90 and feeling naughty, he might go into the time machine room and see both 50 year old Smith 3 get into the time machine and see 70 year old Smith 2 waiting in the shadows watching, and shake hands with them both.
I take it back. That is a sort of loop. But not the one that usually appears in tt stories. I thought of it first!
Mylo.X.
Quantum Scribe
As soon as Observer Smith 1 shakes hands with them both, he is no longer an observer, and 70 year old Smith 2 would have experienced a different life event than that of 90 year old Smith 1 (a handshake) thereby altering the timeline that the universe dictated, there is also at this point a potential "break" of the loop. Smith 3 will carry that memory of the handshake with him into the past, and if that memory does not reoccur with Smith 3, then an alternate/new timeline will be created.
vodkafan
Temporal Navigator
Hi Mylo,
yes, you are correct. That's why I said Smith 1 would be naughty to do that. However, if only Smith 1 and 2 meet, after Smith 3 is safely gone in the time machine, much less damage is done, as both of these gents are "extra" Smiths anyway, and know about the loop.
I have been having more fun with this and have thought of a few more possible outcomes:
Smith 3, without meeting any older Smiths , just decides not to go. (As this is the "present" moment that starts off the loop, I feel this is possible) He lives his life out in his own time. Smiths 1 and 2 still exist, also in his time, at different ages. This stops the loop as no more Smiths are created. However it is possible that only the very first Smith 1 has the option of not going; all subsequent Smiths may be "locked in". (Opinions please!)
Smith 3 dies before his 50th birthday, before he can get into the time machine . Is this possible? No I think not. Because he has already reached 50 before so that is already fixed .
Smith 3 does go but gets bored watching Smith 4. He gets married and has two children, Littlesmith3a(m) and Littlesmith3b(f). These children should not exist.
Smith 3 dies after his 50th birthday . So he doesn't get to see Smith 4 get into the time machine. Does this stop the loop? No. But it means that in his own time Smith will have completely disappeared when he is 50.
Can anyone think of any more?
yes, you are correct. That's why I said Smith 1 would be naughty to do that. However, if only Smith 1 and 2 meet, after Smith 3 is safely gone in the time machine, much less damage is done, as both of these gents are "extra" Smiths anyway, and know about the loop.
I have been having more fun with this and have thought of a few more possible outcomes:
Smith 3, without meeting any older Smiths , just decides not to go. (As this is the "present" moment that starts off the loop, I feel this is possible) He lives his life out in his own time. Smiths 1 and 2 still exist, also in his time, at different ages. This stops the loop as no more Smiths are created. However it is possible that only the very first Smith 1 has the option of not going; all subsequent Smiths may be "locked in". (Opinions please!)
Smith 3 dies before his 50th birthday, before he can get into the time machine . Is this possible? No I think not. Because he has already reached 50 before so that is already fixed .
Smith 3 does go but gets bored watching Smith 4. He gets married and has two children, Littlesmith3a(m) and Littlesmith3b(f). These children should not exist.
Smith 3 dies after his 50th birthday . So he doesn't get to see Smith 4 get into the time machine. Does this stop the loop? No. But it means that in his own time Smith will have completely disappeared when he is 50.
Can anyone think of any more?