Interstellar - The Science in the Science Fiction

Disclaimer: The only Nolan movie that I have watched in theaters is 'The Dark Knight Rises' and it was nowhere close to the Dark Knight. I have never watched 'Inception'. So, this post is not a Nolan fan-boy work!

For movie buffs and science class bunkers, the science contents are italicized so that the movie narration is not disturbed. Stay away from them, if you want. For science lovers, the italicization is there for you to pick them out.

Astronomy & Stephen Hawking are two reasons which made me watch this movie. Astronomy is always fascinating and Neil deGrasse Tyson's 'Cosmos' made me lean more towards it. Hawking's 'A Brief History Of Time' was so mind boggling that I have to read the book multiple times to understand what he actually tries to convey.

The movie opens to an earth of future time with crops failing and frequently occurring dust storms which makes it a difficult place to lead a peaceful and healthy life. Human race is in a survival mode and its future looks bleak.

Cooper (Matthew McConaughey), a farmer and a former NASA pilot is toiling in this dreaded conditions with his father-in-law, son Tom & physics-curious daughter Murphy. Murphy believes a ghost haunts her bedroom and it gives signals time to time about something. Cooper and Murphy finds once such sign, a physical coordinate of a location and their inquisition leads to a secret location of now defunct NASA. The professor at NASA explains the idea of finding a better place to live and their secret progress in achieving that.

The solution: A newly formed Wormhole near Saturn's satellite system, possibly created by some extra terrestrial Aliens, which connects to another galaxy far away with a planetary system having a humongous black hole Gargantua as its center. Three potentially habitable planets Miller, Mann & Edmunds (named after the astronauts who visited and surveyed them) have been identified orbiting the black hole. The Plan A is to have a manned mission to these planets and identify the one that is most suitable for human survival and return back to arrange the transportation of human beings to it. A Plan B was kept in place just in case if there is a chance of no return. A large batch of fertilized eggs kept in earth like condition in the spacecraft will be taken along and they will act as the seeds for future human race to flourish in their new home.

Murphy doesn't want to be away from her Dad but Cooper chooses to be a part of the mission. He boards the spaceship along with three other astronauts including professor's daughter, Amelia (Anne Hathaway) and a robot TARS for the greater good of human race with a promise to return back for Murphy. They reach the spacecraft 'Endurance' stationed in earth's orbit which will be the mode of transport for their complete voyage. Once the booster's are powered up completely and they get a final thrust towards Saturn, the team goes into a self induced sleep till the first checkpoint (wormhole) is reached.

Science:

Now, for people who wonder what is a wormhole. Firstly, it is NOT a black hole. In wormhole, you know that you will end up in a different place but in black hole, you don't know what is there on the other end or if there is really an end?

Wormhole can be easily visualized as the warp zone in Nintendo Classic, Super Mario Bros where you enter a pipe in World 2-1 warp zone and mysteriously come out of World 4-1. In wormhole, we are talking about galaxies that are millions or even billions of light years away. Light year being the distance traveled by light in one year, it would take millions & billions of years to reach there even if we travel at speed of light [~300000 km/s]. Wormhole acts a portal which allows to do this space travel in lesser time. Scientifically wormholes occurs in space where there is a bend in the time-space continuum but such areas are extremely rare in the universe and even if they occur, they are infinitely smaller in size for a spacecraft to travel through and highly unstable to exist for a long time.

In the movie, the director explains the wormhole as the one which was supposedly created by an alien race of intelligence far greater than us. This gives a fair justification as no one has seen a wormhole yet in real life. The wormhole shown above was designed based on basic physics equations for a wormhole and theoretically, wormhole is expected to look like a bubble or fish eye lens image with a peek into the world on the other side.

As Endurance reaches the wormhole entrance, Cooper takes over the task of piloting the spacecraft through it. Once they complete their highly turbulent travel in the wormhole, they exit at the other end in an unknown galaxy with a terrifying black hole acting as a center of planetary system. Their planetary expedition to the first planet Miller is faced by a problem. In fact, this problem would be persistent in other two planets as well. As these planets are influenced by the gravitational force of the black hole, it creates a time dilation effect ie., time moves slower in these planets compared to earth. Since this is a super massive black hole, the more time they spend on Miller, a much farther time runs away on earth. Let us first understand time dilation.

Science:

Time dilation is the primary concept of Albert Einstein's theory of relativity where he explains the time difference observed by a person standing on a platform and seeing himself travelling in a train which just passes by. The core idea behind this is the gravity. Whenever there is an increase in gravity, time slows down. This idea may be far-fetched for some people but we have a real time application of this concept - GPS Satellites.

GPS satellites are positioned in a geostationary orbit around the earth. To know our exact coordinates, ideally we would need inputs from a minimum of 3 satellites. This is easily obtainable with so many numerous satellites used for global positioning purposes but with a technical glitch. The area around an object which contains other objects which can be influenced by the first object's gravity is called as its Sphere of Influence. For eg: Sun has all planets under its Sphere of influence, Earth has moon under its sphere of influence,etc., Similarly both ourselves or our car and the GPS satellites are in the spheres of influence of earth but the gravitational force acting upon things on earth's surface is much higher than the gravity on objects which are farther away from the earth's surface. So, time in GPS satellites will have difference (in this case, in millisecs) when compared to time on earth. For accurate results, the GPS satellites are pre-corrected to an error margin so that the time dilation is taken care of and accurate results are obtained. This is a simple example of time dilation.

Back to the movie, Cooper and team decide to travel to planet Miller and spend as less time as possible there and come back with the results of habitability of the planet. Miller is a watery planet with more than 80% of it covered with water. Their spacecraft lands in one such shallow water body and Amelia and one other scientist start searching for information left behind by the astronaut Miller. Cooper stays back in the spacecraft as he is the pilot. As these two scientists search in the waters, they see  gigantic tidal waves, which is capable of destroying anything, rising at unimaginable heights. Cooper asks them to come back as the situation is becoming hostile. Amelia in the process of collecting more information delays the return which results in death of the other astronaut by the tidal waves (above). They return back to 'Endurance' with a negative result but in the process they have spent 7 hours on the planet which is equal to an exhausting 23 years on earth. By this time, Murphy has grown up and become a scientist in NASA and the professor gets very sick and unable to proceed with his studies.

Science:

 You may have a question that whether such huge tidal waves are possible, The answer is yes and gravity is the culprit again here. We know that the tides in oceans on earth are created by moon's gravity on earth. So, when a planet is situated so close to a black hole, the gravity is infinitely higher in such a planet which influences the occurrence of big tidal waves.

With fuel just enough to visit only one of the two other planets, the crew has to come to decision. Amelia favors to go Edmunds as it has more promising data whereas Cooper and the other astronaut votes for Mann from where data is still being transmitted. Cooper blames Amelia for letting her love for the astronaut Edmunds come in between the goodness of the mankind and she informs him back that they can visit both planets with the existing fuel if they don't return to earth. Finally they decide to go to Mann but to their bad luck, they find it icy and not worthy of human survival. They meet up with the astronaut Mann (Matt Damon) who had put himself into induced sleep hoping someone will come looking out for him.

Mann reveals that there is no Plan A (returning back and transport the people from earth) and the only mission was Plan B (to use the fertilized eggs and start the human race in new planet). He had been sending falsified data in order to lure people to come and rescue him. Mann attacks and breaks Cooper's suit visor and leaves him to die there and flees in the shuttle to 'Endurance' to proceed with Plan B to Edmunds. Amelia finds Cooper and saves him in another shuttle but unable to save the other astronaut who dies in blast which was triggered by Mann in one of his research robots. But by the time they reach 'Endurance', Mann misjudges in docking his space shuttle which explodes the airlock and kills Mann. Endurance goes off in an uncontrolled spin which is then brought under control by Cooper with his piloting skills.

Meanwhile on earth, the professor reveals to Murphy that he has already given up on Plan A as he finds it impossible and all his life's research was devoted to Plan B. Murphy thinks the problem can be solved and Plan A will be possible if she can introduce the concept of Black Hole Singularity in Professor's equation but it is not possible, as no one has ventured into a black hole before and details of the singularity can be known only at the unknown depths of black hole from where nothing can be transmitted.

Nearly out of fuel due to the sudden turn of events, Cooper & Amelia think of a dangerous plan in order to reach Planet Edmunds. Before that, let us see some fact check about black holes.

Science:

Black holes are one of the dangerous & mysterious objects in the universe. To understand Black holes, one should understand the lifecycle of a star. A star is formed in stellar cloud and it may have a lifetime ranging from millions to billions of years when they continue to burn out the hydrogen fuel in them. Once they burn out their stock, two major things can happen for a star based on the mass of the star. If it is low & intermediate mass star, it grows bigger & bigger in size to form a red giant and if it dense and has a lot of mass, it degenerate continuously to form a white dwarf. 

Some white dwarfs have the most painful ending. Chandrashekar Limit (named after Nobel Laureate of Indian Origin, S.Chandrashekar) is the maximum mass of a stable white dwarf star. Once the white dwarf keeps on degenerating, it accumulates mass till the critical mass of Chandrashekar Limit is reached and its core starts collapsing due to the effect of its own gravity which results in a violent explosion called Supernova which spews Stellar matter and powerful cosmic rays all over the universe. This supernova explosion results in formation of highly dense neutron stars which includes pulsars or quark stars and in some other cases, it results in Black holes.

Black holes are highly dense regions of spacetime exerting enormous amount of gravity due to which it starts pulls the matter near to it (planets,moons,etc.,) towards its center even light cannot escape from them. The point from which there is no return is called the event horizon and the area around event horizon emits high radiations called Hawking radiations. As the matter fall into the black hole, it creates a bright disk of aura around it called the accretion disk.

Amelia & Cooper decide to slingshot the 'Endurance' around the accretion disk of Gargantua closest to the event horizon and use the force to inject their spacecraft in the trajectory towards planet Edmunds thus saving fuel consumption. This idea may feel familiar as ISRO used the same concept to use earth's gravitational force to make MANGALYAAN reach Mars in a slingshot path whereas NASA followed a conventional trajectory for MAVEN ot rech Mars faster at the cost of fuel.

As soon as they start their maneuver, Cooper along with the robot TARS separate from Endurance in a shuttle thereby giving more force for Amelia to escape the black hole's gravity and propel towards Edmunds. Cooper & TARS gets sucked into the depths of the black hole.

Till this instant, there are scientifically proven theories which had helped to justify the story-line. Since no one has traveled into the black hole, the director has taken the creativity of a filmmaker to introduce concepts that are not proven but are proposed as scientific assumptions.

Normally in a black hole, as per scientists, a person can be pulled from head to toe and crushed from the sides as well thereby snapping into multiple pieces in the process. In the movie, Cooper ends up in a tesseract with TARS. Tesseract is like a four dimension cube. Let us see the idea of fifth dimension in order to understand what Cooper envisioned in a tesseract.

Science:

Dimension is minimum number of coordinates required to specify any particular point. For eg, a line with length is a single dimension whereas a rectangle with length & breath is two dimension. If you add a dimension of height to it, it becomes 3 dimensional.The fourth dimension is time. Humans normally stay in the fourth dimension and has the ability to perceive any object in three dimensions and manipulate them (in this case, length, breadth & height). They cannot manipulate time. Fifth dimension is when man starts perceiving things as four dimensional model like a tesseract where he can not only move through the 3 dimensions but can also access along the fourth dimension, time like a timeline. For eg., if required, he can go ten years back and see what is happening at the exact same instant.

So, Cooper ends up in one such tesseract which is actually a timeline of events that happens in Murphy's room. Cooper tries to push a book in the bookshelf at the timeline when the small girl Murphy is in her bedroom hoping her father doesn't leave and voila, the book moves. Now, Cooper realizes that it was never a ghost that was trying to contact Murphy but it was Cooper from the future. Now that Cooper is inside the Tesseract and TARS had managed to collect the singularity data, Cooper finds the timeline for the current earth time where the scientist Murphy visits her room for one last time. 

Cooper looks for a way to transmit the singularity data to Murphy before she leaves which will complete the equation and make Plan A a possibility. Cooper finds a watch which he gave to Murphy before leaving and sends the singularity details as Morse code with the help of its gravitational property. Murphy decodes it and finally solves the equation and helps in setting up a space colony habitat close to Saturn from where humans can continue to survive and look for opportunities across the wormhole to settle down.

The question of how Cooper ended up in Tesseract instead being teared down by forces in the black hole is answered by who planned the whole journey. It was not the work of any extraterrestrial aliens, as suggested by professor at the beginning, it was rather the future generation of mankind who enables Cooper to help the survival of mankind.

Now can you see the beauty of a paradox that can be introduced by time travel? Cooper was able to save the mankind because the future gen people put him into the tesseract and made him to send the signals to Murphy but for the thing to happen, Cooper should have initiated the voyage even before the future gen people started sending signals like setting up the wormhole.

This creates a paradox where Cooper is acting on something at two different instances which cannot exist as a continuous events for reasons mentioned above but still influences each other. One of the possible solution for this paradox problem is existence of parallel universes where same person does different kind of activities based on the series of events that are happening within that universe. 

This justifies the final scene where Cooper returns to find a very old Murphy in a space station set up near Saturn and Murphy asks him to start the search for Amelia who has started researches on Edmunds planet for human habitat. I believe the director tried to show that this is Cooper & Murphy from a completely different universe.

With all these science going around, the movie still has an emotional undertone that Love transcends time and it could be the fifth dimension which enables Cooper to reach out to his daughter with the help of other four dimensions.

Note: For people who compare Interstellar to Gravity, both these movies are great in their own aspects. People may tend to connect more to Gravity as the emotional drama is much higher in it where science takes a step back. Interstellar is a science fiction movie where the director wanted to tell an unbelievable space time travel story which still obeys majority of the laws of modern physics.

This has been the longest post of my blog and I feel that I have rediscovered 'Interstellar' as I am signing this off. If you had been patient enough to read till this, I am happy that you have traveled along and hope to see in more adventurous journeys.