Infinite loop?

[_short_]

Hey guys, so I'm kind of new to this whole time travel thing. I know the basics and have a few questions. I came up with a scenario based on something I saw on TV, I changed it a bit. At the end are some questions and it would be awesome if you guys could answer them, thanks!

Let say a guy named Bob is 80 years old. He has had a horrible life due to his getting married at the wrong time. Bob makes a time machine, intending to go back and warn his past self to wait to
get married.

He is successful in his travel, making it back and finding his past self before he ties the knot. He warns past Bob about the future, tells him everything about what his life is like and why it is like that.

However past Bob decides not to listen to future Bob, and marries anyway.

- Now, assuming that future Bob didn't mess up anything in the past to change the future (except of course warning past Bob) would past bob not end up having a horrible life (just as future bob had warned)?
- And would this past bob end up making a time machine, and going back in time to try and stop
himself getting married?
- And if he failed just as future Bob did the first time, would this not cause him to be in an infinite loop? (Assuming of course that every time he traveled back he ended up not stopping the marriage).
- Would having knowledge of the future help him avoid the mistakes made, or will they still end up being made.
- What if future Bob never told past Bob what happened to make him have a horrible life? Would he make the same mistakes still?
- What if future Bob didn't get too past Bob in time? Would he be doomed to complete this loop forever?

Practically, if time travel was possible, what would more than likely end up happening in this
situation. Would there be "rules" about not talking to anyone and interacting in anyway?

I know there are a lot of assumptions about this, but most of it is all theoretical. (except
obviously the part where I ask what practically would happen)

If it's confusing let me know and I'll try to clear that up.
Thanks for your help!

 

[Skarpz]

My opinion would be that he would still make the time machine and go back in time just hoping that past Bob would listen to him and could be in like soemthine in Bill And Ted's Excellent adventure with the phone booth.

Or if after knowing this and going about his life anyways, his future after that point in which he found out that his marriage was horrible he then created a new life for himself after that and did not go back in time since going back in time would not change the situation. Thus creating a new life after that point but then again that could still be what the time travelling Bob still would have done after he saw himself in the past. Nothing really changed at all except him going back in the past or not would be the only difference in my mind.

 

[Darby]

- Now, assuming that future Bob didn't mess up anything in the past to change the future (except of course warning past Bob) would past bob not end up having a horrible life (just as future bob had warned)?

It's a conundrum. On the one hand we can assume that Bob ignored the message altogether and went ahead with making his "marriage mistake".

On the other hand we can also assume that the message was received, contemplated and Bob chose to make his "marriage mistake" because he received the message, i.e. the message itself was the cause of the mistake.

But in either case we are left with the problem that future Bob already knew what had occured in the past. The effect of any time travel influence was already presented to him. No matter what he tries to do "now" by time traveling to the past and altering events, the results of that endeavour have already become a part of his present memories. Further compounding the scenario is the ability, assuming that it didn't work out to his liking the first time, is he can go back again (an infinite number of times, actually) and try to make it work out "correctly" - even though he has a clear recollection of what actually occured. If he had no such memory where would the inspiration come from to go back and change it if he had "happy memories" of his marriage?

Moreover, if there is a Bill who also has a time machine he can look at Bob's life and wife (Bill does not like Bob and wants his life to be a living hell) and every time Bob makes a change Bill goes back and changes it again...and on and on and on.

The above situation is the problem with the all to common "Let's go back and kill Hitler in 1931" scenario. There will always be neo-Nazi Hitler fans who will try to "unkill" Adolph via itme travel. Problem is, where do these people acquire their memories of Assassinated Hitler as well as their memories of Hitler the Leader of Nazi Germany if the past is subject to arbitrary change at will in a time travel enabled society where the anti-Hitler time travelers are always killing him off? How can all this be undone at will if the information, signals for instance sent by radio transmission, are speeding away from Earth at the speed of light for some far away planet to receive? Time travel can't undo those signals. Magic, yes. Real physics, no.

One might say that it's "alternate timelines". Fine (if true - which is not necessarily how the real world works). If that's true then there are an infinite number of "parallel universes" where Germany won WWII, lost WWII, no WWII occurred, Denmark conquered Germany and the Soviet Union, Germany was actually on the right track and produced the first nuclear weapon, aliens took over Earth and defeated everyone, Bozo the Clown became Prime Minister instead of Winston Churchill (or Bob ended up loving his wife, murdered his wife, she murdered him, you name the scenario and it exists in an infinite number of alternate universes).

The real bottom line with time travel is that if it is possible then it is a matter of the universal laws of physics, not magic. Time travel cannot violate the laws of physics if it is part of the laws of physics. Memories don't disappear, people don't vanish without a trace and effects of causes don't turn around and undo themselves because someone time travelled. If that was the case of the laws of physics then sentient life (life with discrete memories of events) becomes an anacronysm for chaos. Who would care about memory if it isn't to be trusted? What would the purpose be for time traveling other than to alter the past if the past is so mutable?

 

[Blair]

Bob should of gone back and told his past wife to be not to marry him, women tend to listen to good advise.

 

[Skarpz]

You know that if we brought today's science back to the past about 2000 years ago then during that time they would think that science was magic and not science. Just a different perspective on things.

 

[Blair]

Yes and you could go back in time with one of these around your neck and no one would know you had a usb stick from 2036.

USB flash drives were invented by Amir Ban, Dov Moran and Oron Ogdan, all of the Israeli company M-Systems, who filed US patent 6,148,354 in April 1999

Nice timing if you came from 2036 and went back to 2000 0/

 

[Blair]

IPhone hidden in wood this would work if you went back to.

 

[Skarpz]

Well, the usb wouldn't work back then and the iPhone would only work for a bout a day or two with no internet or wireless phone connection even in the early 1900s.