ArpitGarg's Weblog

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Posts Tagged ‘explained

Interstellar: Time Travel Climax explained

with 13 comments

Saw Interstellar last night; another one of the notebook movies. I call them notebook movies as you have to sit with a notebook and pen to understand the mind-bending concepts.

I liked the movie overall which has a repeat value for me on the entertainment quotient alone. First half is a bit lazy as it unfolds, but second half is an edge of a seat journey.

This movie is based on scientific nuances of Time Travel, Wormholes, Black holes, which humans know in theory but are yet to corroborate by experiencing physically. It contains directors take on such concepts. In the process it fringes on the boundaries of present scientific knowledge. Hence explanation of entire movie within the layman notion of science might not be entirely possible. However I will relate what I make of it. This post deals with the Time Travel Climax of the movie and the confusion thereof.

Let me call Two Coopers as Cooper farmer (who lives with child Murph) and Cooper bookcase (who went into the blackhole and emerged into the bookcase). Cooper bookcase gave Cooper farmer the coordinates to the NASA facility. Cooper farmer could not have gone to NASA and eventually become Cooper bookcase without knowing these coordinates. How did Cooper (any one of the two) come to know the coordinates in the first place? Someone other than Cooper would have told them right? How does the knowledge of coordinates become self sustaining? Cooper told Cooper, but who told Cooper?

This deals with the concept beyond what humans have experienced physically. The 4th dimension of Time. Post Miller mishap, a desperate Cooper asks Amelia, “Can’t we go back to past, change something to save people?” And Amelia replies, “Time flows in one direction. We can’t change what has already happened”. Her reply was perfect as far as our 3D world goes. But when Time becomes a dimension, we can travel though time too.

Just like we travel in 1D (ants moving in a single line), 2D (cockroach crawling the floor), 3D (insect flying in the room), we can travel through time in 4D (where 4th dimension is Time). In 1D, we can move back and forth on the line; in 2D we can crawl in any direction on the floor and in 3D we can fly in any direction in space. Similarly we can move in any direction in time.

Here comes the catch. Since we have understanding of just 3D world, we start asking questions about, “What will happen if someone goes in the past and kills his grandfather, thereby erasing his own birth?”, Or in the movie’s case, “The Cooper farmer got the coordinates from Cooper bookcase and went to NASA and ultimately reached the bookcase from where he relayed back the coordinates. How?”

Various scientists have tried to explain the Grandfather paradox from the 3D understanding,

  • “A new timeline will emerge when he kills his Grandfather, a parallel universe”, Or
  • “We can’t change anything. What will happen, has already happened. The rules of dimension make sure of it”.

Since we have never experienced the 4th Dimension of time, whatever science of today tells are mere guesses. Researched Guesses to be exact. But still guesses.

As I see in 3D, we can move from one 2D plane to another 2D plane, which would be mind-bending to a person who lives in 2D. Similarly in 4D, we can move through time, front and back. In fact past-present-future all exist simultaneously (don’t think of them as existing at the same time. Time has become a dimension now, not just a measure of past-present-future). The concept of PPP is no more in 4D. Hence Cooper bookcase and Cooper farmer can come to know of coordinate from each other as they both exist simultaneously in 4D.

Since time is not uni-directional in 4D, to think that Cooper bookcase came to know of coordinates only coz he was Cooper farmer in the past is wrong. It’s not Past-Preset-Future but Future-Past-Preset, Present-Future-Past anything. The only fact is that both Coopers has to come to know of the coordinates somehow. Information in 4D does not flow from Father to Son, but can be Son to Father too. In either direction.

Bookcase Cooper does not depend on existence of Farmer Cooper as time is not longer linear (Amelia was hence wrong). Bookcase Cooper came to realize this in Tesseract where he saw the entire timeline of the Murphs room all at once. Initially he tries to stop Cooper farmer by asking Murph to make him STAY. But he realizes it’s futile as laws of 4th Dimension are not allowing it.

What Nolan has portrayed is a 4th Dimension with a closed loop explanation, which says nothing can change. Cooper bookcase can tell anything to Cooper farmer; still he will end up in the bookcase. When he says “Stay”, Cooper farmer ignores the message, whereas he easily believes in Gravitational anomaly message from Cooper bookcase. Rules of universe made sure of it.

Similar is the explanation as to how future humans survived in the first place to be able to put wormhole to attempt saving past humans.

If and When humans conquer the 4D, they may find this explanation to be entirely wrong. Something we have never thought of could be the reality in 4D. Till then we are free to throw off our own hunches and punches just like Nolan has done.


Written by arpitgarg

November 10, 2014 at 6:54 pm

Inception: What is Limbo?

with 37 comments

What is Limbo?
According to one of the Catholic theologies, Limbo is described as periphery to hell. People who are not assigned to hell and have died in original sin, have to bide their time in Limbo. In the movie it is explained as a state in the dream where dreamers end up while trying to go too deep into dream levels or by getting killed in the dream under heavy sedation. It’s an unconstructed dream space of raw infinite subconscious which seems more real than reality itself. Here time runs fast enough for one to lose his/her mind.

What happens when one dies in a dream?
If one dies in a dream, he wakes up to the level above (wakes up to reality if dies in a single level dream). In the opening sequence Cobb shoots Arthur while on an extraction mission and Arthur wakes up on the 1st level. This is true for any normal sedative induced dream. Since the Inception involved going to the 3rd level of dream, it required a special strong sedative, with possible side effects. One such side effect was, if a person dies in the dream, he would end up in Limbo.

Is Limbo like being in Comma?
No, limbo is not a state ad infinitum (comma). One gets out of limbo as soon as the sedation wears off. But since in limbo time runs very quickly, mind tends to burn out, even couple of hours of real time would seem like eternity and one might end up insane.

Is Limbo a shared state?
Limbo is indeed a shared state. As stated in the movie, Limbo would be empty except for the things left by someone who had already been there. Hence near the end of the movie, when Adrain and Cobb went to Limbo they found the world which Mal and Cobb had created there earlier. It does not mean that people in two different dreams altogether, will share the limbo. Only the people physically connected by the PASIV device, sharing a single dream will share the Limbo.

How to reach the Limbo?
1. By getting killed in the dream under strong sedative.
Saito and Fischer got killed and reached Limbo.

2. By trying to go deeper and deeper and states getting unstable
a) Cobb and Mal tried going deeper and deeper and reached Limbo where boundaries between reality and dream vanished.
b) On the snow fortress level, Cobb and Adrian tried going deeper from an already unstable state and reached Limbo. (rememeber, the sedative they took could just take them to Level 3, which too seemed unstable). Adrian explained to Cobb that they needed to go deeper to get Fischer back. They found Mal there (Cobb stated that he had created her projection in Limbo over the period of time from the memories he had of her) who was keeping Fischer captive. They also found the world created by Mal and Cob in Limbo as explained earlier.

How to get out of Limbo?
1. If you kill yourself, you wake up to the real world. (Mal and Cobb committed suicide on the railway track and woke up to reality).
2. Get your own kick in Limbo (free fall for Fischer and Adrian) with the kick on any level above (like using the defibrillator in snow fortress for Fischer). These two synchronized events will take you to the level from where the kick was engineered. Fischer and Adrain got out of it this way in the end.

Why didn’t they try to bring Saito back from Limbo just like Fischer?
Saito could have been brought back just like Fischer with synchronized kicks. But it would have been worthless to the mission. Fischer was important and time was running out. So Adrian and Cobb first found Fischer. He was easy to spot since Cobb knew that Mal’s projection would have captured Fischer to force Cobb to come after her. He went to the place in Limbo (their own apartment) where he could find Mal and thus found Fischer. Meanwhile the kicks started taking effect. There was not much time for them to find Saito. Adrian and Fischer went back and Cobb stayed behind to look for him.

How did Cobb end up again on sea shore and hadn’t aged a bit?
One wakes up on the sea shore when arrive in Limbo. Cobb and Adrian woke up there when they got to Limbo to rescue Fischer. Adrian and Fischer left, leaving Cobb behind to find Saito. Considerable time would have passed during his search for Saito. He should have aged in accordance that time runs pretty fast in Limbo. However he ended up again at the sea shore, un-aged. What happened was, Adrian left Cobb in Limbo and came back eventually to Level 1 where Saito and Cobb were left in the drowning car. Saito was already dead by then but Cobb was alive. He died again due to drowning and his new projection entered Limbo (re-entered). Hence he ended up again at the shore un-aged.

P.S: Queries and Discussion Invited

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