Conundrums If Time Travel Is Possible

[SaxonViolence]

Friends,

 

This is a non-mathematical attempt to explain the Implications of Chaos Theory to Time Travel.

 

It was written for fellow SF Writers who just don't seem to "Get It" in their stories.

 

I'd appreciate comments on how well that I've understood.

 

 

Time Travel Examined

 

 

I want to examine the ramifications of Time Travel in light of what I understand about Chaos Theory and Catastrophe Theory.

 

First of all, you can simply decide that Time Travel is impossible. If

so, then that pretty much ends the conversation.

 

 

Secondly, you can believe that Time itself has some sort of “Gyroscopic Stability” that returns it very close to the “Destined Timeline”, though you may be able to make minor incidental changes here and there…

 

 

 

{In my analysis, I will use the term “Destined” to mean what had already transpired before the “First Time Traveler” muddied the water.}

 

 

I'm going to concentrate on the weather and conception—though everything else is also thrown off its “Destined Path” as well, not just as secondary effects.

 

 

Chaos Theory began when a meteorologist constructed a virtual map of North America. He plotted

One million points and assigned each point a temperature, barometric pressure, humidity, wind speed and direction. Then he set up weather patterns and sent the simulation through tens of Millions of iterations.

 

 

 

He was astonished to find that if you altered one point on the Million point map—any point—just one degree or one barometric point higher or lower and let the exact same starting position evolve...

 

 

In a week or ten days, the weather would be completely different.

 

Even larger and more elaborate simulations confirmed that you couldn't move a grain of sand without altering the weather.

 

 

 

In short, all weather systems are always turbulent and chaotic over a long enough time span.

 

 

 

Now let's say, just for the sake of argument, that the yearly and even the monthly rainfall stayed the same.

 

However one stormy, very raining day will be sunny in the new simulation and the rainstorm become a drizzly day three days earlier and a modest rainfall a week later, on a day that was originally partly cloudy, but with no precipitation.

 

 

 

Now if you're reading this, then that means that you were conceived in the “Destined Timeline”. Let's earmark the Sperm that became half of your genome. What are the odds of this particular Sperm winning the “Genetic Lottery”? The odds are Astronomical against that Sperm before the race. What about after the race? No problem, one of them had to win—and it just happened to be “you”.

 

But if I can go back in time and do something that causes either of your parents to move one millimeter off their “Destined Trajectory”, it's a whole new Sperm Race. The odds against you winning this new race are—once again—Astronomical.

 

#1} When there is a sunny day where it was originally rainy, your parents may not even have had sex that day.

 

 

#2} Even if they do, your mother may not conceive.

 

 

#3} If she conceives, it may be a Girl instead of a Boy or Twins. At the very least, the baby born won't be identical to you.

 

 

If I go back in time and stop long enough to spit on the sidewalk, throw a grain of sand into the Sahara Desert or drop a soft-drink bottle into the Mariana Trench...

 

 

In fact, even if I just obstruct the movement of air with my body, for one second-or less…

 

 

Within a short time—no more than a month or two—the change will have worked its way into the weather patterns all over the Earth. Everyone conceived from that point on, will be a person who was not born in the original timeline...

 

 

And except for perhaps one-in-ten-million, none of the people who “should be” conceived will be.

 

 

Friends, from that point on, it's a whole new ballgame.

 

 

 

Go back to the 1880s to hobnob with the Impressionists for a few days—and when you get back, no one that you ever knew will be here. Your grandparents—maybe even your great grandparents—would never have been born

.

 

One hypothetical solution is to imagine our Timeline as a 4-D “Tree”. If you go back and change things, the “Tree” “Branches” in 5-D Space. The “Branches” grow both in the Fourth and in the Fifth Dimension.

 

 

I never liked the “Many World's” Theory: that our “Tree” branches at every possible decision point. That raises all sorts of Practical and Philosophical Conundrums.

 

 

No, my “Tree” may branch for other reasons besides Time Travelers—but it has to be shaken hard to get it to branch.

 

 

I have been playing with the Idea that any Time Traveler will “Drift” in the 5th Dimension and after a relatively few trips, he'll find that he has wandered so far off course that he'll never be able to go home to a Time Line that is even remotely like his own.

 

 

 

Saxon Violence

Edited December 7, 2012 by SaxonViolence

[DFINITLYDISTRUBD]

If you travel to the past, time will automagically correct itself. Say you go back in time and kill Hitler, one of several things will happen.

1. The event will immediately be undone as you have altered world events to the point you will no longer exist to travel back to kill him.

2. Time will progress, through some miracle you will be born but the event's that inspired you to travel back will not occur, so you will not travel in time negating the first instance causing the timeline to revert.

3. You will find yourself stuck in an endless loop never progressing forward in time beyond the instant you traveled back because your mere presence altered the past.

 

Rearward Time travel is as close to impossible as it gets as any trip to the past would likely result in the time line resetting itself to the instant before the time traveler left because without the event of the traveler traveling back there is no change to the original timeline.

 

Of course the variables are as close to infinite and things can get.

 

As for forward that might be a whole other kettle of fish...I imagine if it were possible the future would be different every time you went even if you kept every trip forward was to the exact same moment...possibly changing with such frequency that everything around would change so fast that you would be unable to make sense of or see, hear, smell, or feel what is going on around you.

[LaurieAG]

Hi SaxonViolence,

 

Have you read Robert Heinleins 'By His Bootstraps'?

 

http://en.wikipedia.org/wiki/By_His_Bootstraps

 

"By His Bootstraps" is a science fiction short story by Robert A. Heinlein that plays with some of the inherent paradoxes that would be caused by time travel. It was originally published in the October 1941 issue of Astounding Science Fiction under the pen name Anson MacDonald. It was reprinted in Heinlein's 1959 collection, The Menace From Earth and in several subsequent anthologies[1], and is now available in at least two audio editions. Under the title "The Time Gate", it was also included in a 1958 Crest paperback anthology, "Race to the Stars".

[SaxonViolence]

I think that I covered your Theory fairly well here:

 

"Secondly, you can believe that Time itself has some sort of “Gyroscopic Stability” that returns it very close to the “Destined Timeline”, though you may be able to make minor incidental changes here and there…"

 

Do you have any Reason for believing that this is the case, other than "Common Sense Prejudice" ?

 

Remember Physicists used to flatly deny Time-Travel was even conceivable.....

 

Largely due to the Fact that it would violate "The Law of Causality".....

 

Then someone sharpened his pencil and demonstrated that it was indeed possible—however inconvenient to travel in time.....

 

And Backwoods Physicist were heard to chumble around their Terbacky chew,

 

"Wail, I guess "The Law of Causality" is one more 'Common Sense Prejudice'."

 

I'll do a Post sometime on my view of "Common Sense".....

 

Briefly "An Answer-Board that those incapable of Deductive Reasoning use in the Place of Deductive Reasoning—and use its supposed lack as a whip to scourge their betters."

 

Something worthy of only the most viciously lampooned caricature of inbred hillbillies.

 

 

Saxon Violence

[CraigD]

Have you read Robert Heinleins 'By His Bootstraps'?

 

http://en.wikipedia.org/wiki/By_His_Bootstraps

... or along the same lines a couple of decades later, again by RAH, All You Zombies (full short text all over the internet, including here)?

[DFINITLYDISTRUBD]

Do you have any Reason for believing that this is the case, other than "Common Sense Prejudice" ?

Certainly, put one drop too much into a glass it will overflow. If you never put that last drop in it will not it will sit there ever ready to but it will not without that last drop.

 

It's how the universe works, One event triggers the next event which triggers the next event and so on. If even one trigger is missing nothing happens beyond that point.

 

In the case of rearward time travel, your traveling back in time is what triggers a change in the timeline. Let's say you disturbed nothing, you were just there. Either you would stand there until you died or arrived back from whence you came. If at the exact moment you traveled back in time, this time you did not you would successfully have erased your last trip from the timeline.

Theory

Some theories, most notably special and general relativity, suggest that suitable geometries of spacetime, or specific types of motion in space, might allow time travel into the past and future if these geometries or motions are possible.^[18] In technical papers, physicists generally avoid the commonplace language of "moving" or "traveling" through time ("movement" normally refers only to a change in spatial position as the time coordinate is varied), and instead discuss the possibility ofclosed timelike curves, which are worldlines that form closed loops in spacetime, allowing objects to return to their own past. There are known to be solutions to the equations of general relativity that describe spacetimes which contain closed timelike curves (such as Gödel spacetime), but the physical plausibility of these solutions is uncertain.

 

 

Relativity predicts that if one were to move away from the Earth at relativistic velocities and return, more time would have passed on Earth than for the traveler, so in this sense it is accepted that relativity allows "travel into the future" (according to relativity there is no single objective answer to how much time has really passed between the departure and the return, but there is an objective answer to how much proper time has been experienced by both the Earth and the traveler, i.e., how much each has aged; see twin paradox). On the other hand, many in the scientific community believe that backwards time travel is highly unlikely. Any theory that would allow time travel would introduce potential problems of causality. The classic example of a problem involving causality is the "grandfather paradox": what if one were to go back in time and kill one's own grandfather before one's father was conceived? But some scientists believe that paradoxes can be avoided, by appealing either to the Novikov self-consistency principle or to the notion of branching parallel universes (see the 'Paradoxes' section below).

 

 

 

Remember Physicists used to flatly deny Time-Travel was even conceivable.....

Then someone sharpened his pencil and demonstrated that it was indeed possible—however inconvenient to travel in time.....

I'd take great interest into the source of information of this quote...who is this someone?

[SaxonViolence]

Well, while I generally remember where I read something.....

 

Except sometimes leapfrogging on the Net can make recalling things precarious.....

 

But I based my judgement on several Episodes on The Learning Channel, Nova and Discovery episodes, and names elude me.....

 

But there is some Professor Dude at a big university—no crack-brained basement laboratory crank—who says he should have Time Travel shortly—though only a few atoms worth.

 

He has a small evacuated glass cylinder rotating very fast and then zaps it with four lasers simultaneously.....

 

I didn't get the fine details.

 

I will do a Google crawl soon, and try to find the ones I meant.

 

However,

 

Let us momentarily take time travel as a Given—As SF Novelists do.

 

Before Chaos Theory it was reasonable to assume that a Time Traveler could go back in time and not alter the course of events drastically—maybe not at all.

 

My point is: There is no possible way to go back in time and not drastically alter the course of history.

 

As I said, even merely standing somewhere—and thus impeding the Air-Flow—for one second would bootstrap itself into Drastic Changes.

 

Now one can imagine some sort of "Temporal Censor" that acts to Prevent Time Travel, or at least acts to largely nullify any changes.....

 

That is certainly Possible but I see no a priori evidence that such a thing "Must" exist.

 

It would seem that such a "Censor" would almost have to be sentient.....

 

And while God may disapprove of Time Travel, he's certainly never said so to me.

 

Personally, If I did have a Time Machine I'd certainly avoid going to the Holy Land during Biblical Times.....

 

I'd hate to be squashed Flatter than a Grape because my presence somehow interfered with the unfolding of Biblical Prophecy.....

 

But outside of that one caveat—I would feel no qualms about encountering any "Temporal Censors".

 

 

Saxon Violence

[DFINITLYDISTRUBD]

My point is: There is no possible way to go back in time and not drastically alter the course of history.

I both agree and disagree wholeheartedly.

I agree that any presence in the past would drastically affect the timeline, But I disagree that any sort of permanent change is possible if the change results in a failure of the time traveler to make the same trip back in time at the exact same moment he traveled back in time from.

[Guest MacPhee]

If time-travel is possible, an obvious question arises, which derives from these basic thoughts:

 

1. The Universe contains only a certain number of particles.

2. Some of these particles are being used to make your own present-day living body.

 

3. When you die, the particles in your body won't disappear - they'll just get dispersed, into other forms: worms, plants, etc.

4. So all the particles of your body will still exist in future times.

 

5. Suppose you get on a time-machine, and travel into the future. When you step out of the time-machine, and set foot on that future world, all the particles in your body will already be there, in that world.

 

6. Therefore, your presence in the future, and existence in bodily form, will necessitate either:

 

a. an immediate duplication of particles (thus violating conservation laws); or

b. an immediate withdrawal of particles from future earthworms, plants, people, etc, to be "sucked" into your intrusive body.

 

Which of these is most likely to happen?

[LaurieAG]

The only place you will see time travel is on the share market where you can sell before you buy.

 

But this is more of a political rule than a natural rule.

[sigurdV]

Nobody will ever meet his future self since: in order to become ones future self one must first be alone at all possible points of later contact in order to become the future self somehow traveling back to a contact point. But the future self cant possibly enter any, since he wasnt already there when the contact points happened.

[Guest MacPhee]

Mightn't the concept of "Time" be just an artefact of language. Language enables to invent the noun "Time".

Then because it's a noun, we assume it's a thing. A thing like "New York City".

 

Which induces us to reason like this:

We can travel through NY City - using a machine (a taxicab). So we can travel through Time - using a time-machine.

 

But isn't this false reasoning, caused by the noun "Time".

Suppose we replace the noun by an equivalent verbal form, such as "Changing".

 

Will we then suppose, that a machine can be built to travel through "Changing"?

[Aethelwulf]

Mightn't the concept of "Time" be just an artefact of language.

 

Better than that... it is probably likely time is purely biological and does not exist outside of consciousness.

[Moontanman]

The OP reminds me of a science fiction story about a time probe that was sent back to record various epochs of time, once started it would bounce back and forth through time getting ever closer to the time that had sent it. When it was launched the beings who sent it were human, as they talked about the images being sent back, each image representing a point in time the machine had visited, the people receiving the telemetry began to change but they were unaware of it. Eventually they became intelligent slugs loudly proclaiming that those who had predicted the probe would change the present were wrong because as far as they could tell nothing had changed...

 

Time is real, try to plan a meeting in a particular place with out the time dimension added... I'll meet you at the top of the Empire State building... a meaningless place unless you know when I'll be there...

[Guest MacPhee]

The OP reminds me of a science fiction story about a time probe that was sent back to record various epochs of time, once started it would bounce back and forth through time getting ever closer to the time that had sent it. When it was launched the beings who sent it were human, as they talked about the images being sent back, each image representing a point in time the machine had visited, the people receiving the telemetry began to change but they were unaware of it. Eventually they became intelligent slugs loudly proclaiming that those who had predicted the probe would change the present were wrong because as far as they could tell nothing had changed...

 

Time is real, try to plan a meeting in a particular place with out the time dimension added... I'll meet you at the top of the Empire State building... a meaningless place unless you know when I'll be there...

 

If time is real, what units, or particles, is it made of.

Can you show someone a particle of "time".

 

I mean, if someone asked: "Is matter real - show me a particle of matter" - then you could show them a proton, or an electron.

Where is the time particle - the "chronotron"?

[Moontanman]

If time is real, what units, or particles, is it made of.

Can you show someone a particle of "time".

 

I mean, if someone asked: "Is matter real - show me a particle of matter" - then you could show them a proton, or an electron.

Where is the time particle - the "chronotron"?

 

 

Show me a particle of length, height, or width and I'll show you a particle of time, why would you expect there to be a particle of time?

[Guest MacPhee]

why would you expect there to be a particle of time?

 

Well, I'd expect it, by following this chain of reasoning:

 

1. "Matter" is not infinitely divisible. It's made of particles.

2. Each particle must take up a certain amount of "space" (otherwise, it wouldn't exist).

3. So, saying that "matter is made of particles", is the same as saying that "space is made of particles".

 

4. Modern physics claims that "space" is actually the same as "time". Hence we have - "Spacetime".

6. From which it must follow, that if "space" is made of particles, "time" must be too.

7. Therefore there must be time-particles - the "chronotrons".

 

8. QED!

Edited January 8, 2013 by MacPhee