MovieChat Forums > In the Shadow of the Moon (2019) Discussion > The time travel explained...

The time travel explained...

posted 5 years ago by [deleted]
7 replies | jump to latest

On IMDB, I was surprised this movie rated a 6.2. Respectable but not extraordinary. Personally, I thought it was one of the most original sci-fi dramas I've seen in the long time.

The directing is somewhat ordinary, but the story was unique and the acting by Boyd Holbrook was gripping. (Michael C. Hall was wasted though...)

Many of the reviews on IMDB and some of the threads here are critical of a 'plot thread'.

Time traveler Rya claims that her death is inevitable once she's told of her upcoming death by Locke. This would seem to imply that time can't be altered.

Yet, we see that the future Apocalypse is averted, suggesting that time CAN be altered.

How can this contradiction be reconciled?

Separately, on the threads here, some people are confused thinking that some sort of time loop is happening which leads to a paradox.

So what's really happening?

There is no time loop happening here. It's all about parallel timelines. Rya comes from timeline-Apocalypse. She's traveling to various points in the past to inject the poison into the people who will eventually cause the Apocalypse. Once they are all injected, a signal is sent from the future to kill them all simultaneously -- although they are separated by years. This will cause a new series of timelines one of which leads to the timeline-NoApocalyse.

However, Rya's death can't be changed because she is travelling upstream to a point before all the new timelines are created.

I've tried to show it in the diagram below.

Ea time she pops ups in the past Rya creates a new timeline by the very fact of her arrival.

Once the signal is sent, THAT future (timeline-Apocalypse) ceases to exist. Locke ceases to exist. The final scene with Locke holding Rya, is taking place in a bright cheery alternate future. Different Locke, different Rya.

On her last jump, the signal is sent from the future, killing all the rebels simultaneously. What confuses people is that we see events happening forward from Locke's POV.

Rya couldn't inject everyone in one trip because of the time travel rules laid out in the movie... she could only travel one way (into the past) at specific times. Constrained by the time she had at each stop, she could only locate and inject a limited number of rebels.

The serial killings weren't really serial killings... it just appeared that way to Locke AND everyone else because years separated the killings. They were passing through time at the normal pace of 24 hours / day. For Rya though, everything happened within a few days...and backwards.

Apocalyse (Rya born in this future)
|
|(3)
|------------>Rya's first time jump, alternate path to a new future, new |
| Locke, new Rya
|
|
|
|(2)
|----------->Rya's second time jump, alternate path to a new future, new |
| Locke, new Rya
|
|
|
|(1)
|------------>Rya's third time jump, alternate path to new future, new Locke, | new Rya

[–] [deleted] 5 years ago

The real problem with parallel timeline movies is that any time traveler to the past cannot return to the future they left.

From the POV of the people in the future -- the ones that send the time traveler into the past -- it would appear simply that the time traveler stepped into the machine/portal/whatever and disappeared, never to return.

Hence, why bother to send a traveler into the past to change it?

In Back to the Future, for example, Twin Pines Marty tweaks the past, then returns to Lone Pines future. He goes to live with his new family, but all his memories are of the Twin Pines timeline. His now-successful Lone Pine parents would be heartbroken to know that their 'son' has no memories of the good times growing up with them. THEIR true son, Lone Pines Marty, disappeared into the past and will never return to them...

[–] ultravioletx (10237) 5 years ago

I felt it was easy to understand, but still ignores the real way we understand multiple timelines.

For example, if you jump to the 90s to kill someone, then jump to the 80s to kill someone, you have created two alternate timelines that will not connect with each other.

However, if you jump to the 80s to kill someone, then jump to the 90s to kill someone, your 90s jump could logically be connected with your 80s jump.

The reason is because every jump you make backwards is always going to be a "new" timeline no matter what you do while you are there.

I give it a pass though because all time-travel movies make the mistake that we somehow have a power source that can achieve such a thing.

There are ways that would allow a backward time traveler to return to their original timeline. But the time traveler's original timeline would not be changed. A doorway that stays open connecting the two realities would allow the time traveler to go back and forth, with his original timeline never changing. That's kinda how the Avengers Endgame quantum realm worked.

[–] [deleted] 5 years ago

"...still ignores the real way we understand multiple timelines."

I think they chose the way they did it to create a better story. We experience Locke's sense of confusion when he learns that the 'first' Rya seems to know his future, the embedded bullet, the key... It creates more mystery than if it had happened the other way... Rya traveling forward through time.

Also by having them cross paths going in different directions, it creates an imbalance of foreknowledge on their part. During their first encounter (Locke's perspective), he knows nothing, she knows everything that will come to pass between them. During their last encounter, the opposite is true... which adds dramatic punch to Locke's anguish. Even if he doesn't kill her in 2015 because of their newly discovered relationship, he knows that she will die within a few days (her POV) because of him anyway... that he killed her anyway.

Yeah, can't debate the power source thing... any form of time travel is likely going to be a massive feat of engineering and energy, if it ever happens.

Also, every time travel movie that I'm aware of ignores the fact that the time traveler would pop out in empty space, since our entire solar system would be somewhere else in the galaxy.

I just enjoy them for the fantasy element...

[–] ultravioletx (10237) 5 years ago

The funny thing is that time travel is actually very easy, you just can't do it backwards. Movement causes us all to move forward through time but since we are all doing it at relatively the same pace we don't notice. But astronauts that orbit around earth several times a day for weeks come back with their watches a minute or so behind because they have effectively jumped ahead. The idea is the closer you get to the speed of light, the slower everything else is around you. When you reach the speed of light, everything around you is stuck in time for eternity. To make your surroundings go backwards you have to go faster than light. There are tricks you do to make particles with no mass go faster than light, but science has no way of getting anything with mass up to the speed of light, let alone surpassing it. Backwards time travel just doesn't seem to be a reality, and is probably why we never see beings from the future.

So I'm in agreement that movies shouldn't have to stick to the rules. Because then there would be no backwards time travel in them.

[–] Windsaar (324) 5 years ago

Wut?

If time travel were easy (possible), people would have...y'know...figured it out.

That aside though, I'd love to know how you concluded (with certainty) that in order to travel backward through time, you must achieve faster than light speed.

Also, what are these "tricks you do" that make particles move faster than light?
The science community would love to know, as you and you alone are the only person to have ever heard of said tricks.

[–] ultravioletx (10237) 5 years ago

We time travel as we move. That is how astronauts return home with their watches slightly behind. They've been zipping around the world at 20,000 mph. I explained this all in the post you replied to. Did you skip over it? Einstein figured it out a long time ago, and pretty much every scientist is aware of it to some extent.

The faster you go, the more time around you slows down. If you reach the speed of light, time stops. If you surpass the speed of light, time moves backwards (in theory). It's all part of Einstein's theory of relativity.

The speed of light is actually the speed of causality. The reason light travels at that speed is because all particles with zero mass travel at the speed of causality by default. What that speed actually means is the rate at which information can be sent from one part of the universe to another.

There are things that can appear faster than light to an onlooker, such as the static field effect, but are not actually going faster than causality. The information exchanged in quantum entanglement also appears to surpass the speed of light.

That aside though, I'd love to know how you concluded (with certainty) that in order to travel backward through time, you must achieve faster than light speed.

I concluded it by the mere fact there has never been a theory that supports backwards time travel involving anything other than ftl travel.

Considering how dismissive and condescending your reply has been, I'd love to know why you think time travel could be possible any other way. And I'm sure the science community would like to know how as well.

[–] Windsaar (324) 5 years ago

I'm aware of Einstein's theory. I didn't ask about astronauts watches, though. I asked which "tricks" people do that make particles move faster than light...since it's never been achieved and is one of the "holy grails" of scientific discovery, the science community (and the world itself) would love to know these tricks.

Einstein also said that achieving light speed is impossible. As an object moves faster, its mass increases, while its length contracts. At the speed of light, said object would have an infinite mass, while its length would be zero...which is an impossibility.

I wasn't asking about most of what you posted. I'm no expert, nor do I claim to be. But I've read up on causality, time/speed and such.

I didn't find my post particularly condescending, even after a re-read 8 days later. I was just curious how you managed to discover tricks to make particles travel faster than light, and why such a monumental discovery would be mentioned in a movie forum and not in science journals around the globe.

Such a feat would defy the known laws of physics and rewrite most of the things we "know". Many theories would become outdated and obsolete over night.

Nowhere in my post did I mention time travel being possible in any capacity...never mind it being possible in "any other way". You asked me if I skipped over your post, and then skip over mine...kind of funny, in its own way.