Piovezan wrote:Hi all. Thank you for all the valuable insights on this fantastic movie that is Interstellar.
Fellow user stevearico settled his personal view on the story logic but I'm not ready yet to do the same.
I've read through the thread and came up with a few thoughts, so I hope someone is patient enough to give them a listen. I'm picking up from stevearico's last thoughts:
"Billiard ball scenarios 1 and 2 are fine and I agree with them as a thought experiment but the story still seems to defy causality". Elaborating: for scenarios 1 or 2 to happen the wormhole needs to be created. In the same way, for the Saturn wormhole to be created humanity has to evolve, and for this to happen it has to be saved in the first place. Which depends on the wormhole being already there. How will humanity's descendants be triggered to create the wormhole?
Taken from
JesseM's Stack Exchange post:
[a probable scenario is that] "the future beings' trip back to the past (or more precisely, their transmission of gravitational signals back into the past) is the very thing that sets their past selves (i.e. humanity) on a course to become those same future beings and make a trip into the past." If I got this part right, how will the future beings transmit gravitational signals back into the past and thus trigger evolution without first creating the wormhole so Cooper can pass through it and reach the tesseract in order to produce them? In order for they to come up with the decision to create it they have to see themselves already going through all that course through their view of the time dimension(s), including the moment they realize they need to create the wormhole -- before they even come up with the idea. Do they simply observe the time dimension(s) and conclude they will have -- or rather that they are going to -- create it?
Also in case it may help, I wonder if someone could provide details on why and how this
specialized review of the movie's science seems to be okay with the story logic. Quoting from it:
"it was obvious immediately that Murph’s “ghost” would turn out to be a black-hole-diving time-traveling Cooper, and that the aliens were in fact advanced humans from the future. They apparently created the black hole and wormhole in the first place, manipulating time and events so things had to unfold the way they did. That part was interesting, though by no means new; Kurt Vonnegut covered this thoroughly in The Sirens of Titan, for example. This might not seem obvious to folks who haven’t watched or read a lot of science fiction, which is fine, but for it to be the Big Reveal fell pretty flat for me." I haven't read The Sirens of Titan and I'm not sure how much insight I could take from Wikipedia.
Any thoughts?
Piovezan wrote:Hi all. Thank you for all the valuable insights on this fantastic movie that is Interstellar.
Fellow user stevearico settled his personal view on the story logic but I'm not ready yet to do the same.
I've read through the thread and came up with a few thoughts, so I hope someone is patient enough to give them a listen. I'm picking up from stevearico's last thoughts:
"Billiard ball scenarios 1 and 2 are fine and I agree with them as a thought experiment but the story still seems to defy causality". Elaborating: for scenarios 1 or 2 to happen the wormhole needs to be created. In the same way, for the Saturn wormhole to be created humanity has to evolve, and for this to happen it has to be saved in the first place. Which depends on the wormhole being already there. How will humanity's descendants be triggered to create the wormhole?
Taken from
JesseM's Stack Exchange post:
[a probable scenario is that] "the future beings' trip back to the past (or more precisely, their transmission of gravitational signals back into the past) is the very thing that sets their past selves (i.e. humanity) on a course to become those same future beings and make a trip into the past." If I got this part right, how will the future beings transmit gravitational signals back into the past and thus trigger evolution without first creating the wormhole so Cooper can pass through it and reach the tesseract in order to produce them? In order for they to come up with the decision to create it they have to see themselves already going through all that course through their view of the time dimension(s), including the moment they realize they need to create the wormhole -- before they even come up with the idea. Do they simply observe the time dimension(s) and conclude they will have -- or rather that they are going to -- create it?
Also in case it may help, I wonder if someone could provide details on why and how this
specialized review of the movie's science seems to be okay with the story logic. Quoting from it:
"it was obvious immediately that Murph’s “ghost” would turn out to be a black-hole-diving time-traveling Cooper, and that the aliens were in fact advanced humans from the future. They apparently created the black hole and wormhole in the first place, manipulating time and events so things had to unfold the way they did. That part was interesting, though by no means new; Kurt Vonnegut covered this thoroughly in The Sirens of Titan, for example. This might not seem obvious to folks who haven’t watched or read a lot of science fiction, which is fine, but for it to be the Big Reveal fell pretty flat for me." I haven't read The Sirens of Titan and I'm not sure how much insight I could take from Wikipedia.
Any thoughts?
Hello, maybe I can help!
You're still thinking in 4 dimensions, where our experience of the passage of time happens linearly: one moment, then the next, then the next, etc. But in the 5th Dimension, time is simply another physical dimension. There is no one moment, followed by the next, followed by the next; each event has always been happening. Now imagine you can view all the events of the entire history of the universe from a bird's eye perspective. It would look something like a strip of movie film rolled out in front of you. In 4 dimensions, we experience time much like the viewer of the movie. The reading device moves in only one direction along the film strip, showing us one moment, then the next, then the next, and only at a certain speed: the speed of our local observation. From this perspective, as events take place in the present and in the future relative to your position on the film strip, there is no true past or present from the perspective of the 5th Dimension. It's all happening at the same time. In fact, even events that the reading device haven't reached yet are still there on the film strip. From the perspective of the device, since change is only observed by it as a series of events going in one direction, causality only appears from the present to the future. We can't go back into the past and see whether something from the future caused that which was in the past to actually happen. Our vantage point restricts our perception of causality as a linear sequence of
present-future actualizations. But just because that's all we see doesn't mean that it is limited to our perception. After all, if there is a 5th Dimension, what would it look like to them?
This is where World Lines become helpful, which is what those long strips were attached to all the objects of the Tesseract. Those strips represent the entire life of each object in every instant of its existence. As a thought experiment, place the second hand of your watch on the shelf and call that instant 1. Now imagine it in instant 2 and place its existence in instant 2 as close as possible to its existence in instant 1. Now do the same for every instant of that second hands existence, each instant being positioned spacially next to the instant just before it. If you followed me this far, you see something like what extended from each object in the Tesseract. Each instant Cooper viewed was simply a temporal pause on any frame of the film strip of any given local set of World Lines. Each "frame" in the Tesseract was a snapshot of any given moment of all the objects in the room as they were at that one instant, but you could see from the linear continuation of each object that the Tesseract was allowing Cooper to view the entire history of each object in every instant, visualized as a flexible strip extending away from each object. Every point on those strips, where ever one might place his finger, would correspond to a different instant in that objects history--not a different physical location necessarily, but a different location in the time of its existence.
Now imagine the film strip from earlier as a world line of any given object. As the reading device travels along the strip (or, as Einstein would say, as the strip travels beneath the device), it has a relative past present and future, depending on where it is relative to any given frame. If the frame is now behind it, it is in its past. If the frame is in front of it, it is in the future. But from the 5th Dimensional perspective, it's all the same. There is no difference. Each moment is "present" to you, since you can look at any one you choose whenever you want. Now, imagine pushing on the film strip ahead of the device--in its relative future--much like Cooper pushed on the World Line of the second hand in Murphy's watch. The bending of the film strip would extend in both directions: it would affect both the device's relative past, present, and future in one and same instant. But then that means the device's relative future affected, or, more precisely, "caused" the events of the device's present, which is observes at the moment. Then, as it continues to travel along the strip, it encounters the exact frame in which the strip was bent. The device (which is us, really, as local observers) now understands that cause of the effect it experienced in the past. Time didn't really travel backwards, since time isn't really traveling. It only traveled backwards relative to the motion of us as local observers trapped in a linear motion.
Keeping in mind that all instants are always happening at the same time, whether relative to our subjective experience of them, there seems to be no reason that causality couldn't run "backwards" in time. After all, causality doesn't absolutely require the forward progression of time even in our own experience of the universe. Imagine two interlocked gears. Gear A turns at the exact instant that Gear B is turned. There is no instant where Gear A moves and Gear B isn't, but then Gear B is moving in the next instant, lest the teeth of Gear A be occupying the exact same space as Gear B in that instant. No, the instant in Gear A turns and Gear B is subsequently turned is indivisible. Ontologically speaking, however, there is a priority of causality on the part of Gear A. If Gear A turns then Gear B must be turning. But there is no temporal division of that causality. Accepting this basic tenet of classical Western philosophy, there is no reason to think that, each instant of time being interlocked in a ever-present for each instant, an event later in the objects existence couldn't affect an event earlier in its existence.
That said, only that universe in Interstellar can existence if and only if future humans choose to go back in time and successfully save themselves. If at this point you ask yourself, "But they can't be future humans if they die on earth. But remember those events ahead of the film strip's reading device? Those events are really happening at the same instant humanity is going extinct in the past. If we consider an infinite amount of metaphysically possible universes all carrying out every possible outcome of every existing object that could ever exist, then in all of those worlds where humanity doesn't go back in time and save itself, then humanity goes extinct. Humanity only avoids this outcome in that universe whereby there would be future humans who do successfully cause a life-saving event in their past, which explains their existence on the other side of the life-saving event, just like the billiard ball thought experiment. Again, every instant happens at the same time, so the past receives no priority over the future. The future is acting on the past in the same way we experience the present acting on the future. So only in that universe in which there is a series of frames causing a life-saving effect in the present of the reading device does humanity avoid extension.
Let's put it all together. Imagine we are moving along the film strip, which is humanity's World Line of existence, so to speak. From our current point of view as we move forward along the frames, it appears we will go extinct. For the sake of the analogy, we see an end to the film strip, and in front of us and along the film strip is an obstacle that will destroy the reading device. But already I must remind you that it doesn't matter what we experience in our linear frame-by-frame progression; whether we are or are not going to go extinct is already determined by whatever is contained along the series of frames ahead of us. Now imagine that out of seemingly nowhere, the film strip bends down and the device passes just underneath the obstacle: same film strip (time line) but slightly altered trajectory. Along that relative future segment of our time line we discover a way to escape the confines of the film strip and learn to actually manipulate and bend it. We look at the strip and see an obstacle that would prevent a reading device from continuing along its path. So we simply bend the strip below it to "cause" our continued existence here and now. Since every effect needs a cause, our being here in the first place to bend out time line needs a cause also. And so only along that theoretical strip where we do in fact press on our literal time line do we preserve it. It doesn't matter where the device is alone the strip at all, since the timeline continues past the obstacle to our determined future if and only if we do in fact press on it to miss the obstacle the device is approaching.
Remember: No instant happens before the other. They have all always happen and are always happening at once. Whether there are future instants for humans beyond where the device is depends on whether those future humans in those frames are in fact forever bending the timeline at the same moment the device approaches the obstacle. If they are, then the device continues along the strip to experience how it does (not did) always cause the time line to be moved. It has to. If it doesn't, then they could never have bypassed the obstacle to begin with. While this seems to destroy free will, it doesn't necessarily if we considered, as I said above, an infinite number of metaphysically possible worlds. In those worlds where humans of the future would NOT choose to avert their doom, then there would never actually be any future humans to begin with; the film strip would end where the device collides with the obstacle. But in that timeline where future humans do choose to avert their doom, then there can be future humans who will actually save themselves. In fact, they've already done it. Just look at the frame in the future where they are always doing. Their decision of the future is already made in the present, and the effect is their own continued existence.
TL;DR
Instead of imagining time as a series of events always moving forward linearly, imagine time as a line of event points all equally happening in the present at the same time. From this 5th Dimensional perspective, no event point has priority over any other; they are all equally existent at once for all time. If this Frame A we are in *now* in this moment can cause effects in the next Frame B we are in right *now* in this moment, then there is no reason to insist that Frame B can't also cause effects in Frame A right next to it. After all, it only precedes it from our vantage point, but from a 5th Dimensional perspective there is no past, present, or future. Everything is equally present at once. If that's the case, then either frame can effect each other. How does this explain mankind's seemingly paradoxical survival in Interstellar? Well, provided that the frames of man's existence on the other side of his expected extinction included events in them in which mankind locates the frames just before his expected demise and "retro"-actively causes events in those preceding frames in which mankind's expected extinction is averted, then there is no paradox at all. It is simply a self-consistent causal loop going from the future to the past (relative to our linear one-directional experience of it) instead of going from the present to the future like we are used to.