Help me understand this time travel mechanic?

[doomdragon6]

Hi all, brand new here and I joined specifically because I need help from people who think about time travel a lot.

I'm taking over a certain project, which is going fine except for one thing: time travel is involved. And it's time travel that as far as I can tell doesn't make any sense at all.

It's all a bit convoluted, so I'm going to give as few relevant details as possible:

1) Character A is killed in the course of the story's events.
2) Characters B and C are sad, and want A back, so they team up with Character D to create a time machine.
3) B, C, and D try to test the time machine by sending a mop back in time, but it catches fire, so they know it's wrong and start making tweaks.
4) Later on, B, C, and D, having learned from their mistakes, believe they have completed the time machine properly. So, this time they test it by sending a note back in time to earlier in the evening, that says, "Do not try to send the mop back in time. It will ust catch fire."
5) They send the note back in time, the time machine flashes and emites a "wave", and the mop pops back into existence, leaning on the wall.
6) C notes that this is impossible, because they wouldn't have been able to fix the time machine if they hadn't sent the mop back in time first.
7) D says that the time machine avoids paradoxes by emitting the wave that it does. He says that they are NOT in an alternate universe, and they are NOT in an aternate timeline, because that is impossible. He says, "We're not in an alternate universe. The time machine has emitted a wave that reconfigures 'our' time to reflect the changes made by the time machine in the past. We're not creating a new timeline here. That is impossible. We're attempting to FIX our time, and the realignment wave helps us do that."
8) The characters note that they have memories of burning the mop, but no memories of receiving a note or -not- burning the mop. So their original memories are intact.

Unfortunately, no more questions are asked and no more explanations given, and I have to figure out how the hell this thing works.

To me, it sounds completely implausible (as implausible as time machines get, anyway), and I can't figure out how it could work.

They're selectively changing the past-- not burning the mop made it reappear, but not burning it did not make any changes. So they changed event 1, but did not change event 2.

And this doesn't help with CHARACTERS going back in time at all. There's no telling how a cognitive person going back in time, actively changing things, and existing, would affect the "present". Could he waltz back up to the time machine "camp" and meet himself? One side of the argument says yes, because they sent a note back and interacted with the world, but the other side says no, because they don't have memories of the event and thus never met him, and all that "could" happen is a copy of the character could pop into existence. BUT, then at what point does time "catch up"? At what point does the machine say, "this is a change" and reflect it in the "present"?

I can't wrap my head around it, but I know there are plenty of complicated time travel mechanics out there, so surely someone can think of something.

 

[Blair]

Hello i read your post, I don't have an answer for you based on the fact that im not a time traveler yet.
Personally travelling back in time would be a waste of time, i would prefer time travel be used for interstellar space travel, that way we could all visit other worlds in the universe. Once we stop treating ours like crap.

 

[Gpa]

I like this one. It's a causality problem, though fictional, (they still make my head hurt) but I will work on it and get back to you. You will probably get a better answer before mine but I will work on it. I do see a connection between 4 and 6 that allows the mop to return and the machine to be fixed.

 

[RainmanTime]

Greetings doomdragon,

I can't wrap my head around it,

I understand your quandary, but I would like to bring you comfort and encourage you to not try to "solve" this. It is a story, and the "wave" is merely a plot tactic to hold the story together. The story still represents a paradox, and the magical wave is just the plot tactic that tries to counter the paradox and hold the story together to maintain the intrigue (not to mention the reader's interest). The scientist would ask the writer for a lot more details about the "wave" that is innocuously introduced. And it is introduce merely so that characters can make their otherwise unsubstantiated statements (i.e. that their memories never changed).

Let me help you try to understand this by one way I describe time. I often use the term Massive SpaceTime Matrix, and I talk about that Mass and Time are vectors, just as Space is a vector (i.e. Space has three dimensions/directions associated with motion through space....often called "X, Y, Z".) So if we focus on time, the obvious question would then be "but what does an X,Y,Z subset really mean with respect to time?" The answer is that instead of X,Y,Z, time is vectorized into orthogonal pseudo spaces along the "axes" called Past, Present, and Future.

But we are not done yet, as this does not get to the explanation we need. We also know that any given direction in space (X, Y, or Z) can be looked at as a line, with an arbitrary "zero" point. Distances along that line stretch positive in one direction away from zero and negative in another direction away from zero. I would like you to think about our "axes of time" (Past, Present, and Future) also each being like a line with an arbitrary zero point, and positive and negative values extending away from zero. But what does this mean? Well, let's look at one axis (Present) and see if we can figure out what it means:

The "0" coordinate on the Present Time axis represents your actual present.
"+" coordinates on the Present Time axis represent POTENTIAL (or possible) times that represent your present. They are potential because they are not your actual present (because 0 represents your actual present), but they are possible presents. For example rather than you being 5'7" tall in your present, you could be 5'8" tall in your present. It is physically possible that the evolution of your life could have followed a different path such that at the present, the now, you were a different height.
"-" coordinates on the Present Time axis represent impossible (according to physics), but certainly conceivable, times that represent your present. For example you could ENVISION in your mind that at present you were 1000 feet tall. The problem with this is that you have not changed your location in space (earth with its attendant gravity) and you have not changed your mass, and the physics of earth would simply not allow a person with your mass to be 1000 feet tall. Gravity would collapse you and your body functions would not work. Because all you did was envision yourself differently in the present time. But what you envision is not supported by the laws of physics.

So now we have our 3 time axes (Past, Present, and Future) and each one has one "end" of their lines that are negative. This forms a 3-D quadrant in "time" (not space). What does this quadrant represent? To put it quite simply, this quadrant represents the ability of Hollywood (and the human mind) to concoct and tell stories about the Past, Present, and Future that just can NOT be true given the physics of our universe. This quadrant represents the entire realm of fiction. Actually, fiction would also include the "+" quadrant in addition to the "-" quadrant of time, because fiction can certainly tell stories that WOULD be supported by the physics of our universe. But the "-" quadrant of time represents all those stories we humans can tell that just could not come to pass given the mechanics of how this universe's physics work.

Your story, because it contains a paradox, "lives" in that "-" quadrant of the 3-D time area.

Did that help?
RMT

 

[Gpa]

doomdragon;
I told you that you would get a better answer before I could get back to you but I will still offer my connection between 4 and 6.
In line 4:

4) Later on, B, C, and D, having learned from their mistakes, believe they have completed the time machine properly. So, this time they test it by sending a note back in time to earlier in the evening, that says, "Do not try to send the mop back in time. It will just catch fire."

The note states "It will just catch fire." Therefore the earlier counter parts KNOW the mop will catch fire without having to send it. Having the knowledge that the mop will catch fire they know what their future counter parts know so they can then tweak the machine and avoid the problem. The mop, having not been sent back would re-materialize as if nothing happened, since it didn't, and what isn't stated but may be assumed, the burnt mop disappeared. So, it's not impossible for the mop to be undamaged. Both past and future characters had the same information. The future characters would not remember the note because 'they' didn't receive it. 'They' burned the mop. The past characters would have no memory of the mop because 'they' didn't send it. 'They' fixed the machine. Perhaps there would be one more wave pulse and the present characters would only know that the machine works.
Or, I could be completely wrong.

 

[Einstein]

doomdragon6

Your time machine appears to be working normally to me. Can I borrow it just to make sure?

 

[Finicus Blunt]

The problem with this story is that it applies two different, competing, mostly incompatible theories, and applies half the logic from each.

However I do have solutions. They require the time machine's wave to be rather extraordinary, but I think that is a necessity.

Your description implies, but does not show, that a different version of the past occurred in which B,C, & D received a note and chose not to send the mop through. Yet they have no memory of this and you state that alternate realities do not exist within the reality of the story. Therefore we can assume one of the two following possibilities happened:

1.) They did read the note, but the machine's wave has modified their memory of the event as part of its paradox suppression technology.

2.) They did not read the note, but the machine's wave modified their reality as part of its paradox suppression technology.

The International Union of Time Travelers have just issued a short alert about this sort of thing on your behalf:
International Union of Time Travelers

 

[Finicus Blunt]

The problem with this story is that it applies two different, competing, mostly incompatible theories, and applies half the logic from each.

However I do have solutions. They require the time machine's wave to be rather extraordinary, but I think that is a necessity.

Your description implies, but does not show, that a different version of the past occurred in which B,C, & D received a note and chose not to send the mop through. Yet they have no memory of this and you state that alternate realities do not exist within the reality of the story. Therefore we can assume one of the two following possibilities happened:

1.) They did read the note, but the machine's wave has modified their memory of the event as part of its paradox suppression technology.

2.) They did not read the note, but the machine's wave modified their reality as part of its paradox suppression technology.

The International Union of Time Travelers have just issued a short alert about this sort of thing on your behalf:
International Union of Time Travelers

 

[Darby]

It's all a bit convoluted, so I'm going to give as few relevant details as possible:

1) Character A is killed in the course of the story's events.
2) Characters B and C are sad, and want A back, so they team up with Character D to create a time machine.
3) B, C, and D try to test the time machine by sending a mop back in time, but it catches fire, so they know it's wrong and start making tweaks.
4) Later on, B, C, and D, having learned from their mistakes, believe they have completed the time machine properly. So, this time they test it by sending a note back in time to earlier in the evening, that says, "Do not try to send the mop back in time. It will ust catch fire."
5) They send the note back in time, the time machine flashes and emites a "wave", and the mop pops back into existence, leaning on the wall.
6) C notes that this is impossible, because they wouldn't have been able to fix the time machine if they hadn't sent the mop back in time first.
7) D says that the time machine avoids paradoxes by emitting the wave that it does. He says that they are NOT in an alternate universe, and they are NOT in an aternate timeline, because that is impossible. He says, "We're not in an alternate universe. The time machine has emitted a wave that reconfigures 'our' time to reflect the changes made by the time machine in the past. We're not creating a new timeline here. That is impossible. We're attempting to FIX our time, and the realignment wave helps us do that."
8) The characters note that they have memories of burning the mop, but no memories of receiving a note or -not- burning the mop. So their original memories are intact.

Unfortunately, no more questions are asked and no more explanations given, and I have to figure out how the hell this thing works.

Yep - it is convoluted and not self-consistent.

1) Character A is killed in the course of the story's events.

Who cares? A is barely mentioned in the story. He's a red herring.

2) Characters B and C are sad, and want A back, so they team up with Character D to create a time machine.

Again, who cares? Why they want to invent a time machine is not important and a distraction. A is still a red herring.

3) B, C, and D try to test the time machine by sending a mop back in time, but it catches fire, so they know it's wrong and start making tweaks.

What was wrong? The engineering? Physics? The theory? Their assumptions about time travel? Loose wiring? Bad insulation? A faulty mop? Another red herring.

4) Later on, B, C, and D, having learned from their mistakes, believe they have completed the time machine properly. So, this time they test it by sending a note back in time to earlier in the evening, that says, "Do not try to send the mop back in time. It will [j]ust catch fire."

If they believe that they have fixed the problem, whatever it was, why send the note with that quote? What is written on the note is irrelevent and does not, by the words on the page, create a paradox of any sort. Red herring - a distraction.

5) They send the note back in time, the time machine flashes and emites a "wave", and the mop pops back into existence, leaning on the wall.

Missing information here. The story didn't state that the mop disappeared, it says it burst into flames. Do you mean that the pile of ash reassembled itself into "a" (not necessarily "the") mop? That's not time travel. That is a violation of the 2nd law of thermodynamics - not entirely impossible but not likely to occur anywhere in the universe during its estimated life span. How does a "time machine" reassemble a pile of carbon, hydrogen and oxygen into a mop? Red herring.

6) C notes that this is impossible, because they wouldn't have been able to fix the time machine if they hadn't sent the mop back in time first.

According to the story they didn't send the mop back in time.

7) D says that the time machine avoids paradoxes by emitting the wave that it does. He says that they are NOT in an alternate universe, and they are NOT in an aternate timeline, because that is impossible. He says, "We're not in an alternate universe. The time machine has emitted a wave that reconfigures 'our' time to reflect the changes made by the time machine in the past. We're not creating a new timeline here. That is impossible. We're attempting to FIX our time, and the realignment wave helps us do that."

Who suggested that they were in an alternate universe? That's not in the story. Moreover, there's no evidence in the story that time travel even occured. The note is never referenced in the story once the mop "reappears". For all they know the machine ate (vaporized) their term paper. After all, it did cause a mop to burst into flames.

8) The characters note that they have memories of burning the mop, but no memories of receiving a note or -not- burning the mop. So their original memories are intact.

As it should be. If they had no recollection of the events they would not have been able to tell the above story. The idea that the machine emits some energy that reassembles burned mops and transports term papers (OK - notes) through spacetime against the thermodynamic arrow of time is unsubstantiated in the story.

So, discounting all of the irrelevent red herrings you have a mop that catches fire, a mop - possibly not the same mop - that appears and a note that disappears. What you don't have is anything that suggests time travel but you do have evidence suggesting that time travel did not occur (no note in the past). Go with the evidence.

 

[Ecce_Signum]

Doomdragon6

Please excuse Darby’s inability to grasp the fictional unsubstantiated account you have written in your obvious innocent attempt to create a scenario you hoped the reader would understand, so that they may be able to assist you in wrapping ‘your head around’ a problem that many consider to be a paradox of time.

Your problem is actually quite simple depending on your point of view.

If you believe that time travel is possible and there is only one time line then anything we do in the past must affect the future. If I were to burn down my house today I would most likely be looking for somewhere else to sleep tomorrow – cause and effect.

However, If you believe there are several universes or time lines then theoretically if I were to burn my house down today I would probably still be able to sleep in the same house tomorrow – but where, what timeline?

The problem with the latter scenario (multiple timelines) is that it fundamentally requires you to believe in two extremely important facts.
1) That there are many versions of you littered around multiple universes each creating a new you and a new time line for every single action you ever undertake.
2) You categorically cannot believe in God (any God) and at the same time (ironically) you cannot believe in evolution?

The problem with the first scenario (cause and effect) is that it requires you to believe (or have faith) in matters that physics currently cannot explain.

I understand your scenario perfectly as (I can see) do a couple of the other members, so do not be disheartened by over complicated engineered responses. Simply ask yourself which situation best fits your belief system and sit back and enjoy the show. Physics will catch up, they have come so far in such a short time and their advancements will continue to expand.

Ecce

 

[Darby]

Doomdragon6

Please excuse Darby’s inability to grasp the fictional unsubstantiated account you have written in your obvious innocent attempt to create a scenario you hoped the reader would understand, so that they may be able to assist you in wrapping ‘your head around’ a problem that many consider to be a paradox of time. [snip]

Ecce

Doom,

My response was admittedly sarcastic - but valid none-the-less. However, the one thing that I did not do is suggest that you were lying (unsubstantiated fictional account) as has Ecce.

You didn't post this on the Fan Fiction forum and you said you are involved in an unspecified project which is probably true (even if its a school creative writing project) and wanted to understand the proposed scenario. There's nothing there to suggest a lie or which even suggests fiction.

As a matter of your project goes the story is a stinker. It is not self-consistent and it draws on the notions of woo-woo "Internet physics" rather than real physics. Relative State Formalisn of Quantum Mechanics (aka "The Many Worlds Interpretation") in its many forms nowhere states than in the macroscopic world burned mops suddenly become unburned mops, people get caught in paradoxes causing their memories disappear or anything else of a kind. On the macroscopic level the world is generally Newtonian and deterministic. At the microscopic level of subatomic particles the world is quantum, chaotic and on that scale basically non-deterministic. On the other hand, at the subatomic level who cares, for example, if one electron-neutrino quantum tunnels into this universe while another tunnels out? They are all exactly alike as are all protons, neutrons and the other 200+ varieties of subatomic particles discovered.