Are these predictions about the Pacific coastline true or just a coincidence?

[Ich]

moving finger,

admitted, GR allows for time travel under certain conditions. It also allows for wormholes and superluminal velocities, if you just can gather enough exotic matter. Don´t misunderstand me, I welcome discussion about it and enjoy it myself. Nevertheless it´s speculation, because we´re just beginning to explore the consequences of GR - already knowing that it cannot be strictly correct (TOE and so on).
To QM, i thought Bohm ran into problems with his hidden variables, and decoherence is up to date. But You´re right, that´s another forum.

 

[moving finger]

BTW , time trave really is speculation, but i´m sure there are two or three things about the behaviour of our universe which would lead you to PROVE it wrong in less than five minutes ;)

ok, Ich, and with the deepest respect, go ahead and be my guest and try to prove time travel "wrong" - I'll be generous and let you have 5 days, never mind 5 minutes

MF

 

[Ich]

ok, Ich, and with the deepest respect, go ahead and be my guest and try to prove time travel "wrong" - I'll be generous and let you have 5 days, never mind 5 minutes

MF

sorry, moving finger, this one was meant for theunknown. I didn´t want him to prove time travel wrong, but out whole universe.

 

[TheUnknown]

You just found out that time travel brings you a great deal of trouble, vanishing universes maybe the least of it. People here know that, and that´s why they´re discussing a lot.
BTW , time trave really is speculation, but i´m sure there are two or three things about the behaviour of our universe which would lead you to PROVE it wrong in less than five minutes ;)

Don't get me wrong! i am not trying to prove time travel wrong, i am trying to prove it right.. but first we need to ask questions about theories, and get rid of ones that are so absurd, if we don't.. we'll never move forward... vanishing universes? i mean c'mon.. destroying the universe because you went back in time 2 times, once told your brother he was going to eat 2 eggs... he did.. so the ones where he didn't suddenly blew up, or vanished, then go again and tell him he's gunna eat two eggs, and he does.. so they vanish too, so then what are you left with? where did that theory come from? where do the universes go if they vanish? what happens to them? it sounds... extremely wishful to me. It's not that simple... well it can't be! or we'd be destroyed already, because obviously the universe is omnipresent when it comes to thinking on a time travel level, so we could have already experienced time travelers? or is it not... do you think we are the first earth/universe to reach 2005? i believe all the questions i have posted here and in my previous posts need to be applied to all time travel theories... it can't be that universes dissapear, you could not just destroy a whole dimension of Earth just from time travel, or I'm sure we'd be destroyed by now being that the universe is omnipresent ... it's really strange isn't it? arg... maybe it's only omnipresent up to our current and previous dates.. would this explain no time traveler visits? really weird.. now I'm lost lol ah.. maybe if time travel exists, then it is not used much... don't you think? or we would have seen something by now? ( i mean does not exist... being that the universe is omnipresent... no futuristic people have visited us yet saying they are time travelers with concrete evidence)

 

[moving finger]

moving finger,

admitted, GR allows for time travel under certain conditions. It also allows for wormholes and superluminal velocities, if you just can gather enough exotic matter. Don´t misunderstand me, I welcome discussion about it and enjoy it myself. Nevertheless it´s speculation, because we´re just beginning to explore the consequences of GR - already knowing that it cannot be strictly correct (TOE and so on).
To QM, i thought Bohm ran into problems with his hidden variables, and decoherence is up to date. But You´re right, that´s another forum.

Godel found a solution to Einstein's equations which allowed time travel but did not require wormholes, exotic material or superluminal velocities. It is generally recognised that within GR as it stands, time travel is possible at least in theory. As to speculation - well even the possibility of manned flight was "speculation" until someone had the curiosity and the courage to try to make it happen for real

The only problem with QM (and it's a problem for ALL interpretations, not just Hidden Variables) is that any viable solution must be non-local. This has been (ignorantly) used as a "proof" that no hidden variables theory can work (von Neumann has a lot to be blamed for!), whereas in fact non-local hidden variables theories can work.

MF

 

[Ich]

theUnknown -
absurd things/theories happen to come along every day. I didn´t say tou should believe it. My point was that you can´t actually DISPROVE it, so join the discussion and have fun.
Moving Finger -
agreed to all. Still QM is (at least) strange, and time travel is not shown to be possible.

 

[DaveC426913]

I get it. I get it!


All the thought experiements about traveling to the past and setting up a paradox make the same assumption; they make the assumption that the past is open, i.e. that it has not happened yet, i.e. that it is still possible to shoot one's mom.

The past is not the future. It has happened. We know that you will not return to the past and shoot your mother because it did not happen. (That's the one advantage of the past, that we know what (will have) actually transpired).

This plays right into the concept that time is an illusion, that past and future are merely the myopia of living creatures. If the past present and future have already been painted on the canvas (this is the "block time" referred to), then there is, simply put, no picture of our universe that was painted where a paradox occurred.

Does this mean we do not have free will? Maybe. It doesn't require the preposterous notion that some 'thing' will prevent you from pulling the trigger, it just means that the universe you are attempting to describe wherein those events occurred, is simply not in existence. You did not shoot your mother. Period.

 

[TheUnknown]

How do you know there is more than one world?


You cannot warn soemone who does not exist.


That's a very big IF


One wouldn't necessarily want to go back to save oneself. As I said, humans are curious animals, or maybe we just want to escape from our existing future and find another future?


lol - what is "free will"?


Define free will first, then we can debate whether it exists...

MF

free will... the ability to make your own decisions? if you believe in time travel you must believe in free will... because you have the free will to go back in time and mess with someone and they have thr free will to agree with you, or not agree with you, and the list goes on... when thinking about time travel you MUST incorporate free will, or certainly the universe will end, to many contradicting factors with no free will.. so by my studies over the last 6 months I've come to the conclusion of many things, that is one of them... about warning someone if they do not exist... that was my point! :) if you decide to time travel and warn someone of something.. how do you know if their parents got together and successfuly had you, or the parents of their parents? or their parents? and all the way back to the ice ages, can you imagine the probability of that happening? it all has an effect, if anyone thing is altered the whole world changes. again it's free will at work... you may be way more special than you think, you may be the only YOU in this universe/world/etc. also how could you go back to escape your future? how do you know your future? and if you did, and we did, don't you think we'd stop our own future from happening instead of escaping? we can never know our future with 100% accuracy... or so i believe, and if we did escape to another world where there was no time travel what would we tell them? how would we have enough room to fit all of humanity into another worldline? would humans be scattered through multiple universes or many worldlines? would we then warn every worldline of the possible catastrophes that lie ahead? see what i mean? this destruction of universes thing cannot exist... i can't find any reasonable logical explanation of it that i can't contradict.

 

[TheUnknown]

theUnknown -
absurd things/theories happen to come along every day. I didn´t say tou should believe it. My point was that you can´t actually DISPROVE it, so join the discussion and have fun.
Moving Finger -
agreed to all. Still QM is (at least) strange, and time travel is not shown to be possible.

i am having fun! you don;'t like me? :(

 

[Ich]

still have ;)

 

[TheUnknown]

I get it. I get it!


All the thought experiements about traveling to the past and setting up a paradox make the same assumption; they make the assumption that the past is open, i.e. that it has not happened yet, i.e. that it is still possible to shoot one's mom.

The past is not the future. It has happened. We know that you will not return to the past and shoot your mother because it did not happen. (That's the one advantage of the past, that we know what (will have) actually transpired).

This plays right into the concept that time is an illusion, that past and future are merely the myopia of living creatures. If the past present and future have already been painted on the canvas (this is the "block time" referred to), then there is, simply put, no picture of our universe that was painted where a paradox occurred.

Does this mean we do not have free will? Maybe. It doesn't require the preposterous notion that some 'thing' will prevent you from pulling the trigger, it just means that the universe you are attempting to describe wherein those events occurred, is simply not in existence. You did not shoot your mother. Period.

ah very bright, i love it ;) but don't forget the possibility of the multiple worlds theory.. although it is just a theory, it does seem very possible. but you may want to rethink your 'can't go into the future cause it hasn't been done', if there are parallel (again i am just using different theories that i believe possible, since they cannot be proved wrong yet) universes, then the universe would be omnipresent, and you could go into the future, because... if you can go back in time, then you can go into the future, because by going back in time, that means that "the past" is still unfolding at that present worldline... therefore the universe is omnipresent, and the future must also be unfolding as well... aren't astro physics tricky.

 

[TheUnknown]

also the destruction of universes from the consequence of time travelers would not make much sense in the fact that... if you told your brother he was going to eat 2 eggs... and he didn't... then EVERY single Earth/universe... and the people in it suddenly disappear "destroy"... so the only logical possible outcome from then on... would be for him to EAT the eggs right? so now this is where you come in... travel back again, and kill him! then what? uh oh! so he dies in every other parallel universe to.. the way this theory is thought out.. is that the consequence of one worldline effects anther? i don't believe in this because it assumes that EVERY universe where he doesn't eat the eggs is DESTROYED, why?! there is still no explanation for this... therefore if I FORCE him not to eat the eggs... the universe ends? remember all the universes where he HAS to eat the eggs has been destroyed... so am i creating a new universe by making him eat eggs? i hardly think so... this is almost laughable, because that's where this theory comes to an end :-/ it can't be true because it is incomplete and lacks a lot of logic, everytime i read it, it sounds like someone who, don't get me wrong, is very brilliant... but it sounds like their wishful thinking, desperately trying to be made true, and i think i exposed a LOT of faults here to undeniably dismiss it? don't get mad at me ich... remember i am not against time travel.. i am just pro fact, and pro logic and reasoning... i want to prove time travel to be right, and i believe it can be done... but the crazy theories trying to scare people who can't analyze the theory for themselves begin thinking time travel is going to destroy the universes... it's abs... ahhem.. you see what i mean now :)

 

[DaveC426913]

I think the key is that the universe getting destroyed does not happen in "our experience" of time. i.e.: "Yesterday, a universe. Today, not so much with the universe."


But it happens outside of time. i.e that universe just didn't happen.


Same thing as with the double slit experiment. Measuring the photon doesn't destroy the offending path, it makes it that the path did not happen.

 

[TheUnknown]

I think the key is that the universe getting destroyed does not happen in "our experience" of time. i.e.: "Yesterday, a universe. Today, not so much with the universe."


But it happens outside of time. i.e that universe just didn't happen.


Same thing as with the double slit experiment. Measuring the photon dopesn't desotry the offending path, it makes it that the path did not happen.

but that is not reasonable... i mean if suddenly a time traveler came and did something that destroyed our World... we'd KNOW, and he would too! so we did exist! and he knew about it as well as us! he still has to go back to his time knowing we existed(being he survived, which he should, since he is not a part of our universe, unless it suddenly self destructs while he's there... this is why i don't buy this theory again.)... therefore we did exist in time, and our universe was both destroyed in his time and ours. either way you put it for US... he still witnessed his actions destroy our universe. That is very interesting... our existence of time.. i'll have to think about that one for a while, let me get back to you, my brain is scattered right now lol. I still don't believe in universes being destroyed by time travel! :)

 

[TheUnknown]

anyone just looking at this page, i ask you to please read all of them :)! i need some input on this, i am studying this topic very hard, i believe time travel is possible, but so far it is beyond our comprehension... and i am trying to move us forward by dismissing old faulty theories, and possibly create new ones.. if anyone would like to collaborate? because before we try and attempt something that has the potential for a number of universal flaws... we should first theorize logically, and lift up every stone, not turn a blind eye to any suggestion, and look around every corner... humans are amazing... look what one of us can do... put 5 brains together and it's very possible.

 

[DaveC426913]

but that is not reasonable... i mean if suddenly a time traveler came and did something that destroyed our World... we'd KNOW, and he would too! so we did exist! and he knew about it as well as us! he still has to go back to his time knowing we existed(being he survived, which he should, since he is not a part of our universe, unless it suddenly self destructs while he's there... this is why i don't buy this theory again.)... therefore we did exist in time, and our universe was both destroyed in his time and ours. either way you put it for US... he still witnessed his actions destroy our universe. That is very interesting... our existence of time.. i'll have to think about that one for a while, let me get back to you, my brain is scattered right now lol. I still don't believe in universes being destroyed by time travel! :)

No. We know that a time traveller will/did not destroy this universe: it exists.

Brian Greene's book 'Fabric of the Cosmos' shows how time can be seen as an illusion. That both past and future already exist**; it is merely our limited perception that we view time as "passing". Since the future exists, it is impossible to have a future exist wherein a time traveller destroys it in the past. That particular series of events just never happened.



**In a nutshell: Using GR, you can show that one man's past is another man's future. If you slice it just so, the two events can be shown to have happened simultaneously in spacetime.

 

[Raparicio]

Paradoxal time

You can supply the paradoxes, by division of x->x' and t->t' formula of A. Einstein. Now, you work with velocities, and this have no paradoxal time. An example of another post is:

https://www.physicsforums.com/showthread.php?t=69849

where is de paradox? In our minds.

 

[TheUnknown]

No. We know that a time traveller will/did not destroy this universe: it exists.

Brian Greene's book 'Fabric of the Cosmos' shows how time can be seen as an illusion. That both past and future already exist**; it is merely our limited perception that we view time as "passing". Since the future exists, it is impossible to have a future exist wherein a time traveller destroys it in the past. That particular series of events just never happened.



**In a nutshell: Using GR, you can show that one man's past is another man's future. If you slice it just so, the two events can be shown to have happened simultaneously in spacetime.

so what you're saying is that ultimately... we'll never have any factual evidence of this?! and all of this is just going to be theories forever, since if we are destroyed we never existed anyway? and no other universes/world parallel with us or not.. would have ever known of us since we were destroyed and therefore did not exist in "time".? doesn't sound very plausible to me... although it does make 100% sense. so then this paradox WOULD be created only in our mind... if all of this NEVER really happens... so are we then... crazy? Maybe this paradox is so much that it doesn't really exist? and it is just a figment of our imagination, and wishful thinking to be able to go back in time and into the future. :) thanks for stuff guys.

 

[TheUnknown]

No. We know that a time traveller will/did not destroy this universe: it exists.

Brian Greene's book 'Fabric of the Cosmos' shows how time can be seen as an illusion. That both past and future already exist**; it is merely our limited perception that we view time as "passing". Since the future exists, it is impossible to have a future exist wherein a time traveller destroys it in the past. That particular series of events just never happened.



**In a nutshell: Using GR, you can show that one man's past is another man's future. If you slice it just so, the two events can be shown to have happened simultaneously in spacetime.

you also stated that, if our universe was destroyed then we never existed.. i have a question... if the time traveler that comes to destroy our world ... let's say world... say he brings a nuclear device with him.. with enough explosives to destroy that world.. sets it on a timer... and then leaves, and takes someone from that universe with him... then what? he saw this world before it was destroyed... so what I'm saying is, it did exist. it was not lost in time, and did not dissapear, and there would be a survivor to tell of this. unless we go by another theory saying that there is only one worldline, and once the nuclear device goes off, they cannot return to any world... and they are stuck in time, traveling inside a black whole until he passes away... or does he immediatly die as well? since his "twin" would be on that world and die when the nuke goes off? and what happens to the man he took with him... whose universe and world never existed? to many flaws. the destroyed universes theory still does not win over any kind of credibility with me :-/ i do believe in time travel... i want to see it happen... but i am looking for a theory on time travel that doesn't come to any dead ends. One dead end, is enough. Or here's another view, say.. since the explanation i was given earlier about this "destroying universes by time travel theory" that's what i'll refer to it as from now on... :P the information i was given about it, was that if you go back in time and tell your brother he will eat 2 eggs... and he does.. then all the universes where he doesn't are destroyed? which still makes absolutely no sense.. then we are limiting our time travel window every time we go back into the past by destroying universes with every action we make(makes no sense to me... seems eventually we'd all be destroyed, and then why would we be here today if the universe is omnipresent and we destroy ourselevs through time travel?)... also by stating this.. this theory is suggesting that the universe is not infinite.. and in fact it is finite.. example.. if there are 100 universes, and you go back in time, and in 50 universes your brother does eat the 2 eggs, and in the other he doesn't... so 50 universes will dissapear... so say you do this.. you go back in time, you don't tell your brother he will eat the eggs.. instead you watch him eat them.. you take him with you to travel to another universe where you tell him he will and doesn't... so how can this first brother exist still if he is supposed to be destroyed? does he disappear before your eyes? or is he still there because of the fact that you did not intervene with him eating the eggs the first time around? starting to make sense? so if you just kept going back in time and taking a your same brother from different times, and continued to experiment with him eating and not eating eggs.. and taking him with you each time to other wordlines, you'd eventually destroy the whole universe through these actions? i hardly think so... thanks guys, just discussing this here has probably amounted to 3 months worth of study. I'd really like the discussions to continue if you guys would please :) i enjoy this very much, thanks guys.

 

[TheUnknown]

? pardon? what does science have to do with something called free will? What is this thing you call free will anyway?


How can someone else be you, unless they really are you, and you them?


that's the whole idea of parallel universes, that different things can happen given the same starting conditions


free will, what's that again?

MF

this is what I'm trying to tell everyone about this multiple world theory, and this other theory which states that universes are destroyed by going back in time... "that different things can happen given the same starting"... the start wasn't 20 years ago.. it was billions... who's to say we survived or didn't survive the ice ages in every worldline, and that mankind even exists? or for those of you who believe in evolution... that we ever evolved correctly? imagine going back in time to a similar Earth with strange beings. who's to say any of us exist in any other multiple world line? everyone i talk to about this always assumes that there are parallel universes with exact replicas of us, just making different decisions... which is a paradox in itself... if we make different decisions... then why couldn't we make the different decision to mate with a different male/female and the list goes on, what I'm saying is people only theorize the way THEY want it to be... and don't open their mind to the IF's and What's... which makes a good theorizer.. GREAT. there are an infinite number of decisions you can choose throughout the existence of human kind that would forever change the world as we knowit ... lwhether it be small... or big decisions. or then again.. maybe the multiple world theory is true.. and my vision of it is correct.(also in multiple universes, why are we so generous to overlook if the Earth would ever even be placed perfectly in the position it's in now to support life?)

 

[TheUnknown]

you guys might like this one.. let's put an extremely fascinating twist on this... going back in time actually results in going into the "future" of our world... but the past's present... since we now understand free will, who's to say an einstein like person would not have been born or came about 1,000 years before ours, and that worldline is technologically 1,000 years more advanced? then this past wordline we are visiting now gives us insite into future technologies etc... so we now open up the past and the future by time traveling into the "past" only... neat huh? the universe is omnipresent with many different outcomes, this is very possible. What i am trying to prove here is we can't use "wishful thinking" theories to use to go by for time traveling information. We can't make the assumption that WE are LIVING in other universes parallel to ours... we have the will to make different choices... BUT since you HAVE to keep the theory alive, you have to say that for some reason we cannot make the DECISION to kill someone in another wordline... whereas their family tree would discontinue, and if they went back in time they would not exist in that worldline, or that our parents could NOT (this is a choice they can make, why deny them it just to fit the specifications of the theory? it's beyond all logic and reasoning, and even physics) get together with smeone else, and we don't exist. why does it seem so hard to accept for a lot of hardcore time traveler fanatics? I swear i think i am going to write a book on this, i think by proving every fault of every theory that is out there, i will in the end be able to put all working parts of these theories together, and have one final and correct solution. Time travel will and does exist! :)

 

[moving finger]

Moving Finger -
agreed to all. Still QM is (at least) strange, and time travel is not shown to be possible.

I'm sorry, but in generally accepted solutions to Einstein's equations time travel IS shown to be very possible.

MF

 

[moving finger]

I get it. I get it!


All the thought experiements about traveling to the past and setting up a paradox make the same assumption; they make the assumption that the past is open, i.e. that it has not happened yet, i.e. that it is still possible to shoot one's mom.

The past is not the future. It has happened. We know that you will not return to the past and shoot your mother because it did not happen. (That's the one advantage of the past, that we know what (will have) actually transpired).

This plays right into the concept that time is an illusion, that past and future are merely the myopia of living creatures. If the past present and future have already been painted on the canvas (this is the "block time" referred to), then there is, simply put, no picture of our universe that was painted where a paradox occurred.

Does this mean we do not have free will? Maybe. It doesn't require the preposterous notion that some 'thing' will prevent you from pulling the trigger, it just means that the universe you are attempting to describe wherein those events occurred, is simply not in existence. You did not shoot your mother. Period.

Congratulations, Dave, this is the SCH hypothesis that we have been discussing in this thread at length (basically : that only self-consistent histories are allowed). If we assume a deterministic universe then this leads to the Block Time picture, and all of our future is just as fixed and determined as is our past, and no time traveller can "change" the past any more than we can "change" the future. It is not that "the past is not the future" as you suggest, it is that both past and future are fixed and determined, both past and future "have happened" in the sense that they are both out there, simply waiting to be discovered.

There are a couple of problems we need to address with this picture however :

1 : If we allow time-travel then in theory you could travel back to your own past and tell yourself in detail what you will have for breakfast tomorrow. Armed with such knowledge, are you seriously telling me that you would accept that your tomorrow's breakfast menu is now fixed, and there is absolutely nothing you can do now to ensure that the prediction turns out to be false? If you believe in the possibility of time travel and in the SCH hypothesis then you must answer "yes" to this question. I answer "no" to this question, not because I believe in something called "free will" or anything airy-fairy like that (what is free will anyway?), but because I believe the absurd situation that presents itself suggests to me that there is something fundamentally flawed with the suggested experiment, and the flaw is probably the possibility of time travel in the first place.

2 : Time travel and the Block Time picture also imply that the universe must be super-deterministic with no possibility of any uncertainty in anything, even at a quantum level (the perfect consistency of spacetime would require a super-deterministic universe). Hence, QM is deterministic (Hidden Variables?) and not indeterministic as the conventional interpretation would have us believe.

MF

 

[moving finger]

free will... the ability to make your own decisions?

The decisions you make are based on the information and experiences in your brain (if you like, based on the software you have been "programmed" with). A computer also makes decisions based on the software that it has been programmed with.
Does this mean that by your definition a computer has free will?
If not, why not?

Sorry, but I think there is something very slippery about trying to define free will, and then to prove that humans act freely...

if you believe in time travel you must believe in free will... because you have the free will to go back in time and mess with someone and they have thr free will to agree with you, or not agree with you, and the list goes on... when thinking about time travel you MUST incorporate free will, or certainly the universe will end, to many contradicting factors with no free will.. so by my studies over the last 6 months I've come to the conclusion of many things, that is one of them... about warning someone if they do not exist... that was my point! :) if you decide to time travel and warn someone of something.. how do you know if their parents got together and successfuly had you, or the parents of their parents? or their parents? and all the way back to the ice ages, can you imagine the probability of that happening? it all has an effect, if anyone thing is altered the whole world changes. again it's free will at work... you may be way more special than you think, you may be the only YOU in this universe/world/etc. also how could you go back to escape your future? how do you know your future? and if you did, and we did, don't you think we'd stop our own future from happening instead of escaping? we can never know our future with 100% accuracy... or so i believe, and if we did escape to another world where there was no time travel what would we tell them? how would we have enough room to fit all of humanity into another worldline? would humans be scattered through multiple universes or many worldlines? would we then warn every worldline of the possible catastrophes that lie ahead? see what i mean? this destruction of universes thing cannot exist... i can't find any reasonable logical explanation of it that i can't contradict.

in all of this you are assuming the past is not "fixed", that somehow the past can be changed. That would require some kind of multiple universes viewpoint (which is legitimate, I agree), but has nothing to do with "free will" (whatever that turns out to be in the end).

MF

 

[Ich]

I'm sorry, but in generally accepted solutions to Einstein's equations time travel IS shown to be very possible.

MF

Yep, and as I said, we already know that GR cannot be strictly true, because it does not match with QM. And even if we stick to GR, maybe the conditions to achieve time travel are unphysical.
Don´t get me wrong: I´m not trying to show that time travel is impossible, because I can´t. My point is that we do not KNOW yet whether it´s possible, even if it´s a solution to a theory. Only experiment can tell for sure.
And after the consequences are so mind-boggling, one rather brings to mind that maybe we´re talking about angels dancing on a pin.

 

[moving finger]

also the destruction of universes from the consequence of time travelers would not make much sense in the fact that... if you told your brother he was going to eat 2 eggs... and he didn't... then EVERY single Earth/universe... and the people in it suddenly disappear "destroy"... so the only logical possible outcome from then on... would be for him to EAT the eggs right? so now this is where you come in... travel back again, and kill him! then what? uh oh! so he dies in every other parallel universe to.. the way this theory is thought out.. is that the consequence of one worldline effects anther? i don't believe in this because it assumes that EVERY universe where he doesn't eat the eggs is DESTROYED, why?! there is still no explanation for this... therefore if I FORCE him not to eat the eggs... the universe ends? remember all the universes where he HAS to eat the eggs has been destroyed... so am i creating a new universe by making him eat eggs? i hardly think so... this is almost laughable, because that's where this theory comes to an end :-/ it can't be true because it is incomplete and lacks a lot of logic, everytime i read it, it sounds like someone who, don't get me wrong, is very brilliant... but it sounds like their wishful thinking, desperately trying to be made true, and i think i exposed a LOT of faults here to undeniably dismiss it? don't get mad at me ich... remember i am not against time travel.. i am just pro fact, and pro logic and reasoning... i want to prove time travel to be right, and i believe it can be done... but the crazy theories trying to scare people who can't analyze the theory for themselves begin thinking time travel is going to destroy the universes... it's abs... ahhem.. you see what i mean now :)

Hi Unknown

Perhaps (with respect) you could try writing a little more coherently and succinctly? I am trying to follow your ideas but I find your writing very chaotic, which makes it difficult.

I gather that you "want" to believe in time travel, but that you find some of the potential paradoxes alarming, also that you seem to favour the multiple universes idea.

I can sympathise with this, since I also find the potential paradoxes alarming. This leads me to think that either there is something fundamantally flawed with the idea of time travel in the first place, or that the solution must be in something like the multiple universes idea.

However, I advise you to drop the idea that any of this is in any way linked to something called "free will". I think you will find that is a non-starter (if only because it is notoriously difficult to agree a sensible definition of free will, and even if one can be agreed I do not see how it could further our understanding of the problem at hand).

MF

 

[moving finger]

you also stated that, if our universe was destroyed then we never existed.. i have a question... if the time traveler that comes to destroy our world ... let's say world... say he brings a nuclear device with him.. with enough explosives to destroy that world.. sets it on a timer... and then leaves, and takes someone from that universe with him... then what?

The SCH hypothesis (assuming one universe) would say this simply would not/could not happen, because it is a non-self-consistent solution.

he saw this world before it was destroyed... so what I'm saying is, it did exist. it was not lost in time, and did not dissapear, and there would be a survivor to tell of this. unless we go by another theory saying that there is only one worldline, and once the nuclear device goes off, they cannot return to any world... and they are stuck in time, traveling inside a black whole until he passes away... or does he immediatly die as well?

No, it simply could not occur as you describe it in "one world" because of the SCH hypothesis.

since his "twin" would be on that world and die when the nuke goes off? and what happens to the man he took with him... whose universe and world never existed? to many flaws. the destroyed universes theory still does not win over any kind of credibility with me :-/ i do believe in time travel... i want to see it happen... but i am looking for a theory on time travel that doesn't come to any dead ends.

Then you have it in your multiple worlds theory.

Or here's another view, say.. since the explanation i was given earlier about this "destroying universes by time travel theory" that's what i'll refer to it as from now on... :P the information i was given about it, was that if you go back in time and tell your brother he will eat 2 eggs... and he does.. then all the universes where he doesn't are destroyed?

no, its not that the universes would be destroyed, because (assuming just one world) those universes never existed in the first place. SCH simply says that the scenario you portray is not possible, the only possible world is one which is self-consistent.

which still makes absolutely no sense.. then we are limiting our time travel window every time we go back into the past by destroying universes with every action we make(makes no sense to me... seems eventually we'd all be destroyed, and then why would we be here today if the universe is omnipresent and we destroy ourselevs through time travel?)... also by stating this.. this theory is suggesting that the universe is not infinite.. and in fact it is finite.. example.. if there are 100 universes, and you go back in time, and in 50 universes your brother does eat the 2 eggs, and in the other he doesn't... so 50 universes will dissapear... so say you do this.. you go back in time, you don't tell your brother he will eat the eggs.. instead you watch him eat them.. you take him with you to travel to another universe where you tell him he will and doesn't... so how can this first brother exist still if he is supposed to be destroyed? does he disappear before your eyes? or is he still there because of the fact that you did not intervene with him eating the eggs the first time around? starting to make sense? so if you just kept going back in time and taking a your same brother from different times, and continued to experiment with him eating and not eating eggs.. and taking him with you each time to other wordlines, you'd eventually destroy the whole universe through these actions? i hardly think so... thanks guys, just discussing this here has probably amounted to 3 months worth of study. I'd really like the discussions to continue if you guys would please :) i enjoy this very much, thanks guys.

seems like you need to separate in your mind the "multiple universe" idea from the "single universe" idea.

In the multiple universe idea then (assuming time travel is possible between universes) there would be no paradoxes and universes could be created and destroyed, and there is no need for a SCH hypothesis.

In the single universe idea then (assuming time travel is possible) it seems that we need something like the SCH hypothesis to ensure the world is self-consistent and there are no paradoxes.

Try not to mix the two ideas and you will be OK.

Hope this helps,

MF

 

[moving finger]

this is what I'm trying to tell everyone about this multiple world theory, and this other theory which states that universes are destroyed by going back in time... "that different things can happen given the same starting"... the start wasn't 20 years ago.. it was billions... who's to say we survived or didn't survive the ice ages in every worldline, and that mankind even exists? or for those of you who believe in evolution... that we ever evolved correctly? imagine going back in time to a similar Earth with strange beings. who's to say any of us exist in any other multiple world line? everyone i talk to about this always assumes that there are parallel universes with exact replicas of us, just making different decisions... which is a paradox in itself... if we make different decisions... then why couldn't we make the different decision to mate with a different male/female and the list goes on, what I'm saying is people only theorize the way THEY want it to be... and don't open their mind to the IF's and What's... which makes a good theorizer.. GREAT. there are an infinite number of decisions you can choose throughout the existence of human kind that would forever change the world as we knowit ... lwhether it be small... or big decisions. or then again.. maybe the multiple world theory is true.. and my vision of it is correct.(also in multiple universes, why are we so generous to overlook if the Earth would ever even be placed perfectly in the position it's in now to support life?)

For the multiple worlds theory to work there must be an unlimited (infinite?) number of parallel worlds, not simply to cater for different human "decisions" but also to cater for every possible outcome in every quantum mechanical event (assuming that QM is not deterministic).

If time travel is allowed, it boils down to :

Either the laws of physics are not super-deterministic and there are multiple worlds to cater for the various possible outcomes and to allow non-paradoxical time-travel.

Or the laws of physics are super-deterministic (even at a quantum level) and there is only one world with one (fixed) past and future, and (to ensure no paradoxes) this must be an entirely self-consistent solution even allowing for the possibility of time-travel.

MF

 

[moving finger]

Yep, and as I said, we already know that GR cannot be strictly true, because it does not match with QM. And even if we stick to GR, maybe the conditions to achieve time travel are unphysical.
Don´t get me wrong: I´m not trying to show that time travel is impossible, because I can´t. My point is that we do not KNOW yet whether it´s possible, even if it´s a solution to a theory. Only experiment can tell for sure.
And after the consequences are so mind-boggling, one rather brings to mind that maybe we´re talking about angels dancing on a pin.

I am inclined to agree that there is something "not quite right" about the idea of time-travel within a single world (ie if we discount the multiple-worlds idea), it seems we are forced into a situation where we need something like the SCH hypothesis to ensure no paradoxes arise, but even with this hypothesis I think the possible outcomes are absurd (such as me traveling back in time and telling myself yesterday what I will have for breakfast today, and then being powerless to do anything but have what I have been told I will have). This absurdity suggests to me there is a fundamental flaw in the idea of time travel that we have yet to discover.

MF

 

[TheUnknown]

The decisions you make are based on the information and experiences in your brain (if you like, based on the software you have been "programmed" with). A computer also makes decisions based on the software that it has been programmed with.
Does this mean that by your definition a computer has free will?
If not, why not?

Sorry, but I think there is something very slippery about trying to define free will, and then to prove that humans act freely...


in all of this you are assuming the past is not "fixed", that somehow the past can be changed. That would require some kind of multiple universes viewpoint (which is legitimate, I agree), but has nothing to do with "free will" (whatever that turns out to be in the end).

MF

A computer may NEVER have "free will" because of the fact that is has already been created by us, that destroys it's whole concept of free will, because yes it IS programmed by the creator, now if you believe in God you may argue that we then.. have no free will, but religion states that God works in mysterious ways, and that we DO have Free will, although he is omnipresent and all knowing, one of many paradoxes yet to be discovered. No i do not believe we are programmed to act a certain way or do a certain thing... we have the software, but we make our own decisions, no one is clicking a mouse or hitting Enter. Humans MUST act freely for time travel to be possible. You cannot dismiss this and then come up with a theory lacking the free actions of humans, and prove it to have no paradoxes, a paradox is a problem, it is not a solution. for free will/timetravel/multi universes to be possible, there must be only one of YOU in the entire universe, and every other Earth is full of different humans or beings. i take that back.. in a sense... there may be another you since there are an infinite amount of universes, but it is not really YOU, or they are living in your current time(i don't want to believe this can happen, but i'll give it the benefit of the doubt, on a quantum multiverse scale i find it highly unlikely you'd ever run into yourself), i take that all back, there must certainly be another you if the multiverse is infinite, but it's not YOU.. if you know what I'm saying? or when you both met, since the universe is omnipresent, your minds would explode or something, how can anyone fathom that? how can YOU be talking to YOU and listening to what YOU are saying... but not knowing what YOU are going to say before you say it, even though it is YOU talking... hm. :-/ u know? different YOU brains each not knowing what the other is thinking, yet they are both YOU. can't be possible?