Closed loop

ShowMeTheCash

I recently watched a movie, I will not say what it is so as not to spoil it but it opened an interesting paradox....


Baby is left at an orphanage.
Grows up.
Becomes pregnant to a guy she just met.
Guy takes off.
During the birth doctors realise she is a hamophrodite.
They have to remove her ovaries due to the complication effectively making her a man.
The baby is also abducted at the hospital and she/he never sees the baby again
A few years later after taking testostorne they tell "Him that he is now producing sperm" She/he is now effetively a fully funtioning man.

Later the now man travels back in time and meets her female self and produces a baby he then steals the baby taking the baby back further in time and leaves the baby at the orphanage.


So The baby, the mother and father are a closed loop, they are all one and the same.

But where did the DNA that makes them originate? It had no beginning no linneage? No grandparents...

Black Swan

MOD: Not posed as a Philosophy question or discussion. Will move to Humanities on the chance that it may foster an interdisciplinary discussion regarding a hypothetical and fictional closed loop.

Cpt Sh!t Craic

I saw that film also.

Same thing occured to me, if the child is it's own parent through time travel and sex change, then it can never have existed in the first place.

Can it?

ShowMeTheCash

It is a take on the grandfather paradox but they have taken it in an interesting direction.

The grandfather paradox you could argue that it would create a new timeline (If you killed your grandfather) and there are or could be multiple time lines.

This however is different, technically if time travel like this was possible you could argue the events are plausible except it would mean the individual created themselves with no lineage.

The Corinthian

TBH it's a bit of a waste of time to ponder on the paradox because it is easy to come up with a paradox in the laws of nature if you get to write those laws and that's exactly what the writer of this story did. In reality, there is no explanation, no solution to the paradox because the story was only written to present a fictional paradox, not to explain how the universe truly works.

Fantasy and science fiction, especially themes of time-travel, have long exploited this gap in our scientific knowledge to do this, so it's nothing new - for example, anyone who's seen the 1930s Flash Gordon serials may remember that when a rocket ship was 'shot down' in space it would 'fall'. Where would it fall? For how long? All questions left unanswered. However, it would seem today absurd to consider them knowing, as we do, that things don't 'fall' in space (unless close to a gravitational force) and that you'd be wasting your time thinking about something that is just fantasy.

On which note, ever consider what is the the maximum air speed of a fully laden Nazgûl?

Pat Mustard

From Stephen Hawking's website:

all we need for time travel, is a space ship that will go faster than light. Unfortunately, in [Einstein's 1905 paper] Einstein showed that the rocket power needed to accelerate a space ship, got greater and greater, the nearer it got to the speed of light. So it would take an infinite amount of power, to accelerate past the speed of light.

Einstein's paper of 1905 seemed to rule out time travel into the past. It also indicated that space travel to other stars, was going to be a very slow and tedious business. If one couldn't go faster than light, the round trip to the nearest star, would take at least eight years, and to the center of the galaxy, at least eighty thousand years.

Hawking doesn't rule out backward time travel, but he asks why we have not been overrun with visitors from the future, if it is possible. He says that one reason may be that backward time travel may not possible until the future

Hawking also mentions the paradoxes and logical inconsistencies that backwards time-travel would cause. In this regard, he mentions two possible resolutions, being a consistent histories approach where the past cannot be changed and an alternate histories approach where the past can be changed. He prefers the consistent histories approach, preferring the theory that it is impossible to change the past.

One is what I shall call, the consistent histories approach. It says that one has to find a consistent solution of the equations of physics, even if space-time is so warped, that it is possible to travel into the past. On this view, you couldn't set out on the rocket ship to travel into the past, unless you had already come back, and failed to blow up the launch pad. It is a consistent picture, but it would imply that we were completely determined: we couldn't change our minds. So much for free will.

Using the approach that Hawking prefers, it wouldn't be possible for a someone to travel backwards in time to change that which had already happened, meaning the the paradoxical story would be impossible.

Using the other approach, the alternative histories approach, 'the universe has every single possible history, each with its own probability', so it would be possible to change the past by selecting an alternate history.

However, the baby has to to exist in the first place in order to grow to adulthood, so it had to have been fathered and conceived by someone other than itself. Therefore the baby can't have been conceived in the first place. Therefore the baby can't exist. Therefore the mother can't exist. Therefore the father can't exist.

ShowMeTheCash

The Mustard wrote: »

From Stephen Hawking's website:


Hawking doesn't rule out backward time travel, but he asks why we have not been overrun with visitors from the future, if it is possible. He says that one reason may be that backward time travel may not possible until the future

Hawking also mentions the paradoxes and logical inconsistencies that backwards time-travel would cause. In this regard, he mentions two possible resolutions, being a consistent histories approach where the past cannot be changed and an alternate histories approach where the past can be changed. He prefers the consistent histories approach, preferring the theory that it is impossible to change the past.


Using the approach that Hawking prefers, it wouldn't be possible for a someone to travel backwards in time to change that which had already happened, meaning the the paradoxical story would be impossible.

Using the other approach, the alternative histories approach, 'the universe has every single possible history, each with its own probability', so it would be possible to change the past by selecting an alternate history.

However, the baby has to to exist in the first place in order to grow to adulthood, so it had to have been fathered and conceived by someone other than itself. Therefore the baby can't have been conceived in the first place. Therefore the baby can't exist. Therefore the mother can't exist. Therefore the father can't exist.

Well that is the paradox. Also to suggest that the baby at some point had to have been fathered and conceived by someone other than itself is incorrect else it would not really be a paradox.

If time travel is possible then this is a paradox is conceivable without the need of an alternative mother and father.

The cool thing is unlike the grandfather paradox where you could use the alternative time line suggestion is that this paradox has to be all in the same timeline they all depend on each other.

Also Hawkings theory of the consistent histories is not his own and is not new, I think the idea of not being able to change history.
1. Supports that time travel backwards cannot happen.
2. Time travel maybe possible but we will never acomplish it.


Also people sometimes talk about "People will never be able to travel back in time" OK fair enough.

But with technology you would not need to send a person back.
Things like communication for example: Having a telephone where you could call someone in the past.

The idea of perhaps the quantum telephone might be feasible but perhaps we need to invent it first and from that point we can received calls from the future.

The Corinthian

The Mustard wrote: »

Hawking doesn't rule out backward time travel, but he asks why we have not been overrun with visitors from the future, if it is possible. He says that one reason may be that backward time travel may not possible until the future

But if backward time travel is possible at any stage in the future, that would mean that it would be possible to backward time travel to the present, returning one to the question of why we have not been overrun with visitors from the future.

Hawking also mentions the paradoxes and logical inconsistencies that backwards time-travel would cause. In this regard, he mentions two possible resolutions, being a consistent histories approach where the past cannot be changed and an alternate histories approach where the past can be changed. He prefers the consistent histories approach, preferring the theory that it is impossible to change the past.

The principle two theoretical paradims on the subject, both in science and fiction appear to be these:

Single fixed timeline, where history is immutable and any attempt to go back in time would fail or ironically facilitate the very timeline that the traveler is attempting to change. Paradoxes are impossible in such a scenario.

Examples of this in film include: Somewhere in Time, Escape from the Planet of the Apes, The Terminator, 12 Monkeys.

Multiple timeline universe, where changes can occur, but this would cause the timeline to 'fork' into a new, parallel one - although the original timeline could also continue to exist. Paradoxes are also impossible in such a scenario; for example, killing your own father would simply mean that you would not exist in the new timeline, but as you came from another timeline where this never happened, there's no paradox.

Examples of this in film include: Source Code, Groundhog Day, Donnie Darko, Primer, The Butterfly Effect.

As such, the closed loop paradox that kicked off this thread is likely based on the latter, as it's not a closed loop per say, but an ever repeating loop creating new timeline forks every time it runs.

ShowMeTheCash

The Corinthian wrote: »

TBH it's a bit of a waste of time to ponder on the paradox because it is easy to come up with a paradox in the laws of nature if you get to write those laws and that's exactly what the writer of this story did. In reality, there is no explanation, no solution to the paradox because the story was only written to present a fictional paradox, not to explain how the universe truly works.

Fantasy and science fiction, especially themes of time-travel, have long exploited this gap in our scientific knowledge to do this, so it's nothing new - for example, anyone who's seen the 1930s Flash Gordon serials may remember that when a rocket ship was 'shot down' in space it would 'fall'. Where would it fall? For how long? All questions left unanswered. However, it would seem today absurd to consider them knowing, as we do, that things don't 'fall' in space (unless close to a gravitational force) and that you'd be wasting your time thinking about something that is just fantasy.

On which note, ever consider what is the the maximum air speed of a fully laden Nazgûl?

Specifically.

The Corinthian wrote:

Fantasy and science fiction, especially themes of time-travel, have long exploited this gap in our scientific knowledge to do this, so it's nothing new.

I find this statement amazing!

Jules Verne wrote stories of travelling to the moon in a rocket in 1867 long before we sent a man to the moon.

Science fiction maybe just an idea but these ideas came before the facts.
The fiction shaped the future not the other way round.

Some people might argue our entire existance is a waste of time but we are getting into existential debate with that. Also some might also argue that time cannot be wasted.

Pat Mustard

The Corinthian wrote: »

But if backward time travel is possible at any stage in the future, that would mean that it would be possible to backward time travel to the present, returning one to the question of why we have not been overrun with visitors from the future.

That's what occurred to me initially too. But I'm not going to contradict the likes of Stephen Hawking!

A possible way to reconcile time travel, with the fact that we don't seem to have had any visitors from the future, would be to say that it can occur only in the future. In this view, one would say space-time in our past was fixed, because we have observed it, and seen that it is not warped enough, to allow travel into the past. On the other hand, the future is open. So we might be able to warp it enough, to allow time travel. But because we can warp space-time only in the future, we wouldn't be able to travel back to the present time, or earlier.

This picture would explain why we haven't been over run by tourists from the future.

Pat Mustard

ShowMeTheCash wrote: »

Well that is the paradox. Also to suggest that the baby at some point had to have been fathered and conceived by someone other than itself is incorrect else it would not really be a paradox.

You say that this is incorrect. It seems more likely that the scenario is incorrect/impossible. I will get back to this point.

ShowMeTheCash wrote: »

If time travel is possible then this is a paradox is conceivable without the need of an alternative mother and father.

But it doesn't make any sense. Saying 'because it's a paradox' is not an explanation.

ShowMeTheCash wrote: »

Also Hawkings theory of the consistent histories is not his own and is not new, I think the idea of not being able to change history.
1. Supports that time travel backwards cannot happen.
2. Time travel maybe possible but we will never acomplish it.

In Hawking's consistent histories approach, it is not possible to change the past, so this is approach is not relevant to your scenario, where backwards time travel takes place in order to change the past. It appears that we would have to look at David Deutsch's alternative histories approach, where is possible to change the past, as long as the history remains self consistent.

ShowMeTheCash wrote: »

The cool thing is unlike the grandfather paradox where you could use the alternative time line suggestion is that this paradox has to be all in the same timeline they all depend on each other.

According to what Hawking says about the alternative histories approach, it is not possible to transfer into an alternative history. The 'closed loop' scenario, has the same character (who is three characters in one) hopping from one alternative scenario to another, altering the course of the other characters' lives. The history does not remain self-consistent in that scenario. Hawking would say that this is impossible, under the alternative histories approach.

Instead, the universe has every single possible history,each with its own probability. There must be a possible history in which there is a lasting peace in the Middle East, though maybe the probability is low.
In some histories space-time will be so warped, that objects like rockets will be able to travel into their pasts. But each history is complete and self contained, describing not only the curved space-time, but also the objects in it. So a rocket can not transfer to another alternative history, when it comes round again. It is still in the same history, which has to be self consistent. Thus, despite what Deutsch claims, I think the sum over histories idea, supports the consistent histories hypothesis, rather than the alternative histories idea.

Otherwise, we appear to be completely into the realms of science fiction, and the most likely way to explain the 'closed loop' scenario is to adopt The Corinthian's Multiple Timeline Universe approach:

The Corinthian wrote: »

Multiple timeline universe, where changes can occur, but this would cause the timeline to 'fork' into a new, parallel one - although the original timeline could also continue to exist. Paradoxes are also impossible in such a scenario; for example, killing your own father would simply mean that you would not exist in the new timeline, but as you came from another timeline where this never happened, there's no paradox.

Examples of this in film include: Source Code, Groundhog Day, Donnie Darko, Primer, The Butterfly Effect.

As such, the closed loop paradox that kicked off this thread is likely based on the latter, as it's not a closed loop per say, but an ever repeating loop creating new timeline forks every time it runs.

In any event, it appears that the closed loop scenario is science fiction.

ShowMeTheCash

The Mustard wrote: »

You say that this is incorrect. It seems more likely that the scenario is incorrect/impossible. I will get back to this point.


But it doesn't make any sense. Saying 'because it's a paradox' is not an explanation.


In Hawking's consistent histories approach, it is not possible to change the past, so this is approach is not relevant to your scenario, where backwards time travel takes place in order to change the past. It appears that we would have to look at David Deutsch's alternative histories approach, where is possible to change the past, as long as the history remains self consistent.



According to what Hawking says about the alternative histories approach, it is not possible to transfer into an alternative history. The 'closed loop' scenario, has the same character (who is three characters in one) hopping from one alternative scenario to another, altering the course of the other characters' lives. The history does not remain self-consistent in that scenario. Hawking would say that this is impossible, under the alternative histories approach.


Otherwise, we appear to be completely into the realms of science fiction, and the most likely way to explain the 'closed loop' scenario is to adopt The Corinthian's Multiple Timeline Universe approach:



In any event, it appears that the closed loop scenario is science fiction.

I don't know if you are making an argument, reitterating what I have already said or agreeing with me, but any anycase.
All time travel scenarios are science fiction, closed loop, consistent histories or muti-verse we don't know! Neither does Hawkings...

BTW the closed loop supports the consistent histories theory and not the Multiple Timeline Universe approach but we can let that slide.

The Corinthian

ShowMeTheCash wrote: »

Some people might argue our entire existance is a waste of time but we are getting into existential debate with that. Also some might also argue that time cannot be wasted.

I think you misunderstand what I consider to be a bit of a waste of time. Musing about going to the moon, or time travel, or faster than light travel or whatever is not a waste of time. Musing the often contradictory logic in the invented laws of nature in science fiction, as if this is how nature actually works, is.

Consider a film like Event Horizon. In it faster than light travel is based upon warping space - a popular enough theory - and discussing that is valid enough IMHO because it is a valid theory. But trying to work out the details based upon how the 'gravity' drive in the film is described as working by the actors is daft. The script writers for Star Trek TNG used to insert the phrase 'technobabble' in their first drafts, where a 'scientific' explanation was due, which would be later added for effect, but of secondary importance to the rest of the script.

The Mustard wrote: »

That's what occurred to me initially too. But I'm not going to contradict the likes of Stephen Hawking!

Maybe there was a glitch in his speech synthesizer that day.

The Mustard wrote: »

In any event, it appears that the closed loop scenario is science fiction.

Well yes, I was just citing the only explanation on the basis of existing scientific theory. Beyond that we really should just think of it as entertainment TBH.

The Corinthian

ShowMeTheCash wrote: »

BTW the closed loop supports the consistent histories theory and not the Multiple Timeline Universe approach but we can let that slide.

How can the former, which involves backward time travel support a theory that you say "supports that time travel backwards cannot happen"?

Pat Mustard

ShowMeTheCash wrote: »

I don't know if you are making an argument, reitterating what I have already said or agreeing with me, but any anycase.
All time travel scenarios are science fiction, closed loop, consistent histories or muti-verse we don't know! Neither does Hawkings...

BTW the closed loop supports the consistent histories theory and not the Multiple Timeline Universe approach but we can let that slide.

I was disagreeing with you, saying that it couldn't happen outside of fantasy. But it was interesting.

Spanish movie on time travel, loops, etc; Timecrimes.

ShowMeTheCash

The Corinthian wrote: »

How can the former, which involves backward time travel support a theory that you say "supports that time travel backwards cannot happen"?

In terms of the scenario that is outlined it supports consistent histories as the existance of the time traveller is dependant on all the events happening without deviation there is no alternative thread or multi-verse.

The grandfather paradox whereby I go back in time and kill my grandfather is the case in point. If I go back in time the suggestion is I cannot kill my grandfather, but what if i do?

The two examples are different.

ShowMeTheCash

The Corinthian wrote: »

Musing about going to the moon, or time travel, or faster than light travel or whatever is not a waste of time. Musing the often contradictory logic in the invented laws of nature in science fiction, as if this is how nature actually works, is.

If quantum physics has tought me anything it's all laws are invented, all our understanding and measurements are limited by our own understanding. The use of our measurements impact the outcome.

I place no distinct line between the former and latter above, I see them as one and the same.

The Corinthian

ShowMeTheCash wrote: »

In terms of the scenario that is outlined it supports consistent histories as the existance of the time traveller is dependant on all the events happening without deviation there is no alternative thread or multi-verse.

Just because you don't see the alternative thread in the story, doesn't mean it's not there.

ShowMeTheCash wrote: »

If quantum physics has tought me anything it's all laws are invented, all our understanding and measurements are limited by our own understanding. The use of our measurements impact the outcome.

When all laws are invented by scriptwriters, I'll accept your point.

ShowMeTheCash

The Mustard wrote: »

I was disagreeing with you, saying that it couldn't happen outside of fantasy. But it was interesting.

Spanish movie on time travel, loops, etc; Timecrimes.

I think we have our wires crossed I am not stating anything and I do not know what you mean by "fantasy".
I think the closed loop scenario is an interesting one.

It's a bit like saying your future self would come back in time to talk to you.
And in turn later in life you would travel back in time and give the exact same talk.

So let's say your future self simply says "Red".
Then you decided when I go back in time I am going to say "blue".

The above supports multi-verse.

You say "Red"
Supports consistent histories.

Whether this argument is even relevant and there are options beyond our understanding is probably more plausible but I think these questions are worth thinking about and not a waste of time.

ShowMeTheCash

The Corinthian wrote: »

Just because you don't see the alternative thread in the story, doesn't mean it's not there.

When all laws are invented by scriptwriters, I'll accept your point.

We are talking about consistant history theory with the example set out in the story, that the past cannot be changed, my suggestion is the scenario supports it which it does.

The Corinthian

ShowMeTheCash wrote: »

We are talking about consistant history theory with the example set out in the story, that the past cannot be changed, my suggestion is the scenario supports it which it does.

Doesn't explain where the person originated, which the multiple thread scenario can explain, as well as the supposedly closed loop, which isn't really closed - we've just seen one repeating section in it.

ShowMeTheCash

The Corinthian wrote: »

Just because you don't see the alternative thread in the story, doesn't mean it's not there.

When all laws are invented by scriptwriters, I'll accept your point.

My Degree with Math helps me with the laws in physics which BTW the screen scriptwriters did not "invent" but merely adopt to present an intersting story.

I am not concerning myself with the movie, simply the idea of the loop.

ShowMeTheCash

The Corinthian wrote: »

Doesn't explain where the person originated, which the multiple thread scenario can explain, as well as the supposedly closed loop, which isn't really closed - we've just seen one repeating section in it.

Your logic is incorrect you suggest the multiple thread scenario can explain it?

How?

The Corinthian

ShowMeTheCash wrote: »

My Degree with Math helps me with the laws in physics which BTW the screen scriptwriters did not "invent" but merely adopt to present an intersting story.

Do the scriptwriters have degrees in math too?

ShowMeTheCash wrote: »

Your logic is incorrect you suggest the multiple thread scenario can explain it?

First iteration of the loop the child has different parents and lineage. Loop plays out, this time with the adult effectively returning back, changing history, and creating a clone of itself. Having changed history the timeline forks and thereafter forks every time the loop repeats.

ShowMeTheCash

The Corinthian wrote: »

Doesn't explain where the person originated, which the multiple thread scenario can explain, as well as the supposedly closed loop, which isn't really closed - we've just seen one repeating section in it.

Are you suggesting the following:

Mary and Paul have a baby, Tammy.. This is the origin

Tammy goes back in time and say gets rid of the folks.
Tammy later becomes Tommy.
Tommy goes back in time has a baby with Tammy.

Then what? You think this baby is now Tammy? What if the baby is a boy?
You know the baby is going to look different even if both parents are the same person?

So you take that baby back in time? Then what they are not the same person.

ShowMeTheCash

The Corinthian wrote: »

Do the scriptwriters have degrees in math too?

I don't know some might, what difference does it make?

The Corinthian wrote: »

First iteration of the loop the child has different parents and lineage. Loop plays out, this time with the adult effectively returning back, changing history, and creating a clone of itself. Having changed history the timeline forks and thereafter forks every time the loop repeats.

You obviously fell asleep during biology

ShowMeTheCash

I will simplify:

The paradox here we are exploring is the what came first paradox "Chicken or the egg".

Now excluding how we know the progression of evolution to work.

The idea being, we cannot have an egg with out a chicken and we cannot have a chicken without an egg.

The Corinthian

ShowMeTheCash wrote: »

Tammy goes back in time and say gets rid of the folks.

There's no need to get rid of them. Also my understanding is Tammy never time travels, or needs to, only Tommy.

Then what? You think this baby is now Tammy? What if the baby is a boy?
You know the baby is going to look different even if both parents are the same person?

Doesn't have to look or be the same beyond the hermaphrodite quality. Each loop could have a different baby - remember, we've only seen one loop. At the end of the day, they only need to be able to repeat the same role, not be the same person. That they are the same person is an assumption on your part.

ShowMeTheCash wrote: »

I don't know some might, what difference does it make?

So you are suggesting that all scriptwriters will have a detailed understanding of theoretical temporal physics to a level that allows you to put them on the same level as scientists?

ShowMeTheCash

The Corinthian wrote: »

There's no need to get rid of them. Also my understanding is Tammy never time travels, or needs to, only Tommy.

Doesn't have to look or be the same beyond the hermaphrodite quality. Each loop could have a different baby - remember, we've only seen one loop. At the end of the day, they only need to be able to repeat the same role, not be the same person. That they are the same person is an assumption on your part.

So you are suggesting that all scriptwriters will have a detailed understanding of theoretical temporal physics to a level that allows you to put them on the same level as scientists?

You really are not getting this.

1. Forget the movie, forget the scriptwriters the idea is not theirs it is an adapted idea of a pre-existing paradox.

2.

The Corinthian wrote: »

Doesn't have to look or be the same beyond the hermaphrodite quality. Each loop could have a different baby

I am now beginning to question your basic math skills, you suggest that each loop can have a different baby... Hmmmm really? The creation of a "new" baby does not undo the creation of the last so now instead of having one baby we now have an infinite number.

I am going to ignore the whole "hermaphrodite quality" as the idea is completely missing the point.

The Corinthian wrote: »

At the end of the day, they only need to be able to repeat the same role, not be the same person. That they are the same person is an assumption on your part.

No, we are trying to explain a paradox, you are trying to come up with a completely different scenario which isn't even a paradox, you don't even need time travel to test your theory.

Your new baby is not replacing the last all you are suggesting is two dffierent people are making a new baby on each iteration, so what happens to the iteration from before?

circadian

The Corinthian wrote: »

First iteration of the loop the child has different parents and lineage. Loop plays out, this time with the adult effectively returning back, changing history, and creating a clone of itself. Having changed history the timeline forks and thereafter forks every time the loop repeats.

This was my interpretation when watching the film in question.

Pat Mustard

ShowMeTheCash wrote: »

I think we have our wires crossed I am not stating anything and I do not know what you mean by "fantasy".
I think the closed loop scenario is an interesting one..

I'm not sure why you say that we have our wires crossed. I am simply stating my belief, based upon what I wrote above, that the closed loop scenario appears impossible.

ShowMeTheCash wrote: »

It's a bit like saying your future self would come back in time to talk to you.
And in turn later in life you would travel back in time and give the exact same talk.

So let's say your future self simply says "Red".
Then you decided when I go back in time I am going to say "blue".

The above supports multi-verse.

You say "Red"
Supports consistent histories.

Whether this argument is even relevant and there are options beyond our understanding is probably more plausible but I think these questions are worth thinking about and not a waste of time.

I think that the argument is relevant. However, it isn't possible to argue about whether there could be some approach which is beyond our current understanding. You are saying that it could be one of the 'unknown unknowns', which are not possible to debate:

There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know. Donald Rumsfeld