This is the English version of my previous post.

한국어 버전은 여기에서 확인하실 수 있습니다.

I prefer to watch movies alone or talk face to face, but I received a lot of personal requests to write down the review from people who have seen the “Interstellar” movie. Although I majored in physics, I did not study it deeply about astrophysics so I was a little hesitant about it. I wanted to deliver the theoretical foundation and background of modern physics such as space-time, interstellar travel as easy and fun as possible in terms of physics to the public. My first Interstellar movie review posted on Facebook in November 2014 has been getting a lot of attention as it spread to many places and finally it has been introduced through Internet press. Now, I want to show it to all steemit friends. I did not include any formulas so that they are easy to understand. I hope everyone who interested in this post to read and enjoy it.

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1. Special relativity theory

The reason for the difficulty of relativity is that we have to accept that absolutely believing truth is not actually true. Aristotle thought that it was the essence of all objects in the world to be stationary, but Galileo thought that the stationary state was essentially nonexistent. Relativity theory describes the relationship between two objects moving at different speeds. The speed difference that occurs when two moving objects look at the other object is called relative speed. When the relative velocity is constant, it corresponds to the special relativity theory. Time is not just the order in which the incident happened. The order of the events is different between the person who is stationary and the person who is moving. It means that time flows differently. When you talk about the sequence and time of an event, it does not make sense if you do not specify who is observing the event.

The following is a direct explanation of the special relativity without formulas.

If you see an object moving at constant velocity
(1) Time on the object is slow.
(2) Length of the object is seen as reduced.
(3) Mass of the object appears to increase.

In other words, time and space are not absolute physical quantities, but relative physical quantities that depend on the reference system being measured. Time and space are closely related, not independent variables.

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2. General relativity theory

Special relativity theory explains the relationship between two objects that are moving away or approaching at a constant relative velocity. On the other hand, General relativity theory can be said to be a generalization by eliminating the limitation of constant relative velocity covered by special relativity. What should be considered if the special condition that the relative speed is constant disappears? It is an acceleration!

Gravity is a typical case where constant acceleration movement occurs. The introduction of gravity requires the introduction of relative acceleration. Einstein started with this relative acceleration and proposed general relativity and gravity theory. In the special relativity theory, we introduced the 4-dimensional space-time (Minkovsky space), so we could deal with time and space with the same physical quantity. Both matter and energy can be handled as same physical quantity. Is it amazing? It is the beginning of general relativity theory that we regard four different physical quantities (time, space, matter, energy) as the same physical quantity and consider them as relative physical quantities that can be transformed into each other, not absolute physical quantities.

(1) Time and space are the same physical quantity. (time = space)
(2) Matter can be converted to energy. (energy = matter)
(3) Space around matter bends. (matter = space)

The energy in the gravitational field (gravity force) causes the space to bend. The space we live in is bent by gravity, and the time goes slowly by gravity. The degree of curvature of the space (curvature) determines the mass of the matter, which determines the motion of the matter.

In order for a single law of motion to apply equally to all space-time, space-time that receives gravity must bend. So we can say that relativity is given in space-time to adhere to the absoluteness of the law of motion. We arrive at the conclusion that the time of an accelerating object or an object affected by gravitational acceleration flows slowly.

Do you agree that general theory of relativity is the most important element in Interstellar films?

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3. Black hole

General relativity plays a decisive role in predicting the existence of black hole. A black hole is a kind of star whose gravity is huge. In the solar system, the light passing around a massive sun is a little bent due to gravity, but the light passing around a black hole is extremely curved, swirling, and eventually sucked into a black hole. Once the light is sucked into the black hole, it can not come out again, so it looks black in our eyes.

As the special relativity theory suggests that matter and energy can be converted to the same physical quantity, the energy absorbed by the black hole is converted into mass, which makes the space more distorted. As the gravitational field (bent space) is an energy and this energy is converted into mass, the mass also forms an additional gravitational field. In other words, the gravitational field is creating the gravitational field!

In the movie, the reason why the time is extremely slow on a planet with a powerful gravitational field similar to that of a black hole, and the phenomenon of a huge wave standing like a wall can be explained scientifically. In fact, the tide is caused by gravity.

Stephen Hawking, who we know very well, has greatly contributed to the theory of black hole by introducing the quantum field theory into the curved space. Through the study of cosmology and quantum gravity he has greatly improved black hole thermodynamics. I recommend his book, The Grand Design, which explains that the universe was born naturally as a result of the action of the laws of physics.

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4. Singularity

The law of constant speed of light, did you heard a lot, right? Nothing can make the moving speed beyond the speed of light. The speed of light is so fast that it almost ignores gravitational attraction. For reference, light has no mass, and any matter with non-zero mass need infinite energy to get speed of light theoretically.

Imagine a certain star shrinking. What happens if it gradually condenses and collapses close to the point? The density and gravity of shrinking star dramatically increase. Then there will be nothing to escape from gravity. Even the light! These condensed points are called singularity.

The everything (time, space, matter, energy) will condense and disappear into this singularity. It's a deep state, absolutely nothing and all at the same time. The great physical formulas are useless in this singularity. The laws of physics can not allow the existence of singularity.

There is a great deal of confusion here. In addition to ideal spheres that are perfectly spherical, there are also singularities in actually observable stars. Any time a star collapses, there is always an singularity. Do we have to abandon the achievements of physics we have accumulated so far because of this singularity, which is a special point where the physical laws do not apply and the time, space, matter, energy do exist and do not exist at the same time?

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5. Big Bang theory

When the boundaries of the whole universe are trapped in a shrinking region, singularities arise. This is the case of collapsing stars. The presence of singularities from the collapse of real stars is evidenced.

Let's consider the direction in which time reverses in flexing space-time coordinates. What if you look back over time in dense materials in space? And if there is a singularity there? The reverse reaction of the collapse is Big Bang!

Of course not these friends.

Back again, Big Bang was first foreseen by George Gamow, Ralph Alpher, and Robert Herman in 1948, and in fact, Arno Allan Penzias and Robert Woodrow Wilson experimentally received the Nobel prize in 1978 for the observation of remaining cosmic background of the Big Bang.

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6. Wormhole and white hole

Due to the presence of black holes, physicists have carefully proposed the existence of wormholes and white holes. The basic assumptions are as follows. If there is a black hole that sucks everything, there is a white hole that will spit it out. A wormhole is a path connecting a black hole and a white hole. When entering a wormhole through a black hole, it may be possible to travel to the place where white hole is located.

However, until now, only the presence of black holes has been proved, and the existence of wormholes and white holes has been proven to be unrealistic and rather unrealizable. That's because of Hawking's black hole evaporation theory. This research, also called Hawking radiation, overturns the interpretation of existing black holes.

If the Hawking radiation is true, there is no wormhole and white hole because the black hole pulls a part of the pair annihilation and the black hole does not absorb energy indefinitely, but it can emit particles and lose energy.

If the Hawking radiation is not true, beyond the horizon of space-time, the escape velocity for gravity would be faster than the speed of light, so it is very unlikely that it reaches the opposite side of the wormhole. Also, any matter that passes through the wormhole is twisted in space-time and so that it is not easy to maintain the original shape.

In the movie, the white hole itself was not even mentioned, and the presence of the wormhole for the interstellar travel was introduced only to the extent of a narrow passage connecting space-time by introducing the helper of five-dimensional world.

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Reference

The reason for the existence of a black hole is that it was theoretically predicted and experimentally observed and verified. The following is the content that can be confirmed based on the observation of the existence of a black hole.

“Astronomers have found convincing evidence for a supermassive black hole in the center of our own Milky Way galaxy, the galaxy NGC 4258, the giant elliptical galaxy M87, and several others. Scientists verified the existence of the black holes by studying the speed of the clouds of gas orbiting those regions. In 1994, Hubble Space Telescope data measured the mass of an unseen object at the center of M87. Based on the motion of the material whirling about the center, the object is estimated to be about 3 billion times the mass of our Sun and appears to be concentrated into a space smaller than our solar system. For many years, X-ray emissions from the double-star system Cygnus X-1 convinced many astronomers that the system contains a black hole. With more precise measurements available recently, the evidence for a black hole in Cygnus X-1 — and about a dozen other systems — is very strong.” (http://hubblesite.org/)

As you can see, the black hole is not a visual observation, but a confirmation of its existence through the velocity of the gas cloud that orbits the galaxy. Strictly speaking, it is 'proving' the presence of black holes through observations.

A few years ago, it was argued that a black hole could not exist mathematically, so it was impossible to completely confirm the presence of a black hole. However, in February 2016, the first observation of gravitational waves from the Laser Interferometer Gravitational-Wave Observator (LIGO), confirms the existence of orbiting two black holes (black hole binary system), and their merging. This is the first direct observation of a black hole and proves the general theory of relativity prediction, so the existence of a black hole is in fact proved.

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7. Five-dimensional

Dr. Cooper, the main character, experiences the five-dimensional world that is embodied in the black hole and twists the space-time with the help of the five-dimensional world helpers, and transmits information to himself and his daughter through the gravity. Personally, I think that the exaggerated setting of the SF movie is added here. In other words, it can be regarded as a cinematic license.

Even though we can accept the existence of black hole, there is no wormhole in the real world that can be traveled by interstellar travel created by outside helpers like in the movie. Also, mankind has never actually reached a black hole. In the distant future, if science and technology are further developed and there is a human being near a black hole, it is doubtful whether there is a way to pinpoint what is happening in it and deliver the information out of the black hole.

It is well expressed that time, space, matter, energy are intertwined. However, it is strange and illogical that the physically and mentally well present human is present inside black hole.

Even if he jump over time, space, matter, energy through gravity, it is too dramatic that the main character is accidentally located in the space-time overlapping her daughter's room in the unknown black hole, which is at least dozens of light years away from the interstellar journey. The film can not explain all this without the help of the five-dimensional world helpers.

Oh my gosh!

Therefore, it is hard to find a physical basis after entering the black hole. Let's just accept the premise that love of family can transcend space-time with the license of SF movies. Maybe it would be Christopher Nolan's message that he wanted to deliver through this movie.

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8. Causality

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Let's deal with the Copenhagen interpretation that measurements itself affect the state quantum-mechanically. A quantum state exists in a superposition of different eigenstates with different eigenvalues. The action of measuring or perturbing collapses the quantum state to make it a specific one of the allowed states. We can not know which of the specific states will be determined. Only probabilities can be estimated. It means that natural phenomena are subject to probability.

A state in which two or more quantum states are closely related to each other is called a quantum entanglement state. Until we measure it, we can not know the state of the two particles. But at the moment of measurement, the state of a system is determined and it immediately determines the state of another system entangled with the system. It's as if the information was instantly moved from one system to another. It's like teleport!

The principle of physics explaining that two objects that are spaced far apart can never directly affect each other, is called locality. It is the principle that information must be exchanged in order to influence each other, and the transmission of such information can not be achieved at a faster speed than the speed of light by the theory of relativity.

For example, let's think of the earth orbiting around the sun, assuming that there exists only sun and the earth in the universe. If the sun suddenly disappeared from the universe at any moment, what would happen to the earth's movement? Classically, as soon as the sun disappears, the earth can be thought of as moving straight out of its orbit. However, considering the theory of relativity, applying the principle of locality, the linear motion of the earth begins after the sun has disappeared and its influence has propagated at the speed of light to reach the earth.

Three physicists (Albert Einstein, Boris Podolsky, Nathan Rosen) directly refuted the Copenhagen interpretation with the EPR theory that physical presence must have such a locality.

Ultimately, through John Stuart Bell's experiments, it revealed that quantum entanglement can not be applied to the principle of locality and that information can be mediated without going around the system. The EPR theory is not a truth that can be applied to all physics and is not explained in the quantum entanglement state. So it remains the name of the EPR paradox and is often mentioned in connection with the reversal of causality and the destruction of synchronicity.

Einstein said “God did not play backgammon.” He have established the theory of relativity, which can be called the beginning of quantum mechanics. However, he have shown the most negative attitude to quantum mechanics by axioms that natural phenomena are subject to probability. Is it surprising that Einstein even said something wrong?

The quantum entanglement state free from the principle of locality shows that the state of one particle can instantly determine the state of another particle. When thinking about transcending of causality and space-time, with accepting the cinematic setting of human love, I think that the strong entanglement of love has become the background to connect with each other in the 5-dimensional space spread in the black hole.

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9. Gravity equation

In the film, gravity equation is focused as if they are the key to saving the humanity. At first, I guessed that the gravitational equation would be a super-string theory(theory of everything) adding time, space, matter, energy to the grand unified theory to combine the four forces of nature. Eventually, I could not figure out exactly what the identity of gravity equation was in the latter half of the story.

In order to implement Plan A in the film, it is presumed that the super-string theory would be matched for the gravity equation, but even if you solve the equation, there are too many requirements that need to be solved realistically in order to progress enough to catch up with the theory. However, in the film, it was only half a century after completing the gravity equation, and it seemed like human beings developed the technology for a new living space.

Above all, it is necessary to have observation data on the singularity inside the black hole to complete the gravity equations. Also, the transmission of observation data on the singularity inside the black hole is realized with the helper of 5-dimensional world. I was disappointed to see that it implies the impossibility of realizing the grand unified theory.

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10. God

There are some people who interpret the helpers who exist in the five-dimensional world as an indication of the existence of god. After entering a black hole in the first place in the film, all settings are just imaginary. It is only mentioned that the five-dimensional helper who transcends time, space, matter, energy is the next generation of human beings. There is no hint or suggestion of god anywhere.

As for personal commentary, there is a problem in itself if there is a god who created all things and laws of the world. If god is not free in all things and laws of physics, then god's existence is a contradiction itself. and if god is free, god's being can not come from nothing, and the transcendental god for the god is needed. It falls into the circulation logic for god's existence. This is a personal opinion and I just think that religion should not be explained in scientific terms.

Nevertheless, if someone want to give religious elements to the film, I can not help but think that it is more objective not to put the logic of science and the belief of religion in the same category and not to apply it to SF movies.

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11. Communication

The communication system has broken down after passing through the wormhole. The transmission is impossible and the reception was only possible. However, no matter how fast communication is, electromagnetic wave communication can not be able to transmit or receive information at a speed higher than the speed of light.

If someone is traveling through the wormhole, will there be a way to communicate over space-time? Is it possible to receive at least as much as it does in the film? There are still questions about how the planet pioneers who were beyond the wormhole sent their data before the Dr. Cooper’s team departs.
Even if quantum communication becomes possible in the future, it is doubtful that quantum entanglement remains stable and reliable beyond the wormhole. If you accept the setting of the movie that can travel through the wormhole, it could be a little convincing in anyhow.

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12. Spaceship

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No matter how excellent the pilot's capabilities were, the scene of the docking of spacecraft to the fast-spinning space station, which had been orbiting due to an explosion, was too much dramatic. We do not know how much fuel they used after docking, but it was hard to accept scenes where the engine was sprayed to stabilize a station that is several tens of times larger in size and weight.

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13. Earth

In the film, the earth suffers from extreme climate change, disease, and food shortages. Sandstorms are close to the natural disaster levels so it adversely affect bronchial health and crop seeds become extinct.

But in the meantime, we have been able to identify the well-supplied electricity, the car moving around here and there, the computer with excellent performance, and the robot that is much more advanced than it is now. It was quite strange considering the fact that only a few engineers remain.

In addition, there was a disaster of yellow-dust, but the roads around the school were clean, the people were playing and watching the baseball game. It was a very awkward landscape.

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14. American heroism

All the people who are trying to save the planet are all NASA Americans. It was not an extreme form, but it was a bit disappointing because the color of American heroism seemed intentionally exposed.

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15. Actor / Lines

The actors' performances and lines were artistic, making the story more natural and dramatic to accept the narratives that may seem boring until reaching the highlight of the movie. The most memorable lines among them is following.

Do not go gentle into that good night.

Old age should burn and rave at close of day.

Rage, rage against the dying of the light.

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16. Visualization

I think it is the visual beauty that has a great influence on the perfection of SF movie. We can see great efforts to visualize surreal situations such as the widely unfolded universe, the interstellar travel through space-time via the wormhole, the event horizon of black holes, and the five-dimensional world of infinite unidirectional array inside black holes. In that sense, I want to give a high score.

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17. Overall assessment

Physics, which is difficult to reach easily to the public, has expressed very delicately.

As the SF film that portrays the adventure that crosses space-time dimension, the survival of mankind and the love of the family have been appropriately melted, and it has sublimated into a desperate sentiment, which made me feel incredible perfection and realism.

Fresh ideas and great visual effects all look wonderful.

I think Interstellar will be a huge challenge to the next film that is made up of space and interstellar travel in the future..

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18. Three-line summary

(1) A science fiction movie that made you excited after a long time.
(2) Exquisite reflection of physical facts on both materials and images.
(3) Adventures that cross the space-time dimension of mankind's survival and family love.

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• Reference : Kip Stephen Thorne, The Science of Interstellar.

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# YHH

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