Saturday, 8 November 2014

Things to know about Interstellar (2014) Explained - Part 2

SPOILER ALERT: The purpose of this article is to provide explanations about the real, theoretical scientific concepts presented in the film, Interstellar (2014) so that people can have a greater understanding of this unusually complex film. If you haven't watched the film and you do not wish to know the specific details of the film, please stop reading and come back here later if you're interested to know more.

The following explanations are provided based on my understanding of the film after watching it the first time on November 5, 2014 and what I know about the basics of quantum mechanics and Einstein’s Theory of Relativity. Note that these are highly complex theories with lots of mathematical calculations and formula. I've tried my best to make them as short, simple and concise as possible for easier understanding without the maths.

If there are any mistakes found in this article, please kindly provide any comments below so I can rectify it.

For my review of the film, please visit this link:


Now, let's proceed to explain what quantum theory is about:

  Quantum mechanics/quantum physics/quantum theory

      Any theory of physics in which the Universe has no single history or even an independent existence and objects do not have single definite histories. It seeks to explain the Universe from a subatomic (microscopic) point of viewIt is a branch of physics that provides a mathematical description of much of the dual particle-like and wave-like behaviour and interactions of energy and matter. It states that matter can be both a particle and a wave. It departs from classical mechanics primarily at the atomic and subatomic scales, the so-called quantum realm.

At quantum level, matter doesn't exist at a fixed state; instead it exists in a cloud of ‘probability’ called the ‘wave function’ where it exists in all states and in all locations. Only by ‘looking/observing’ at the particle, we collapse the ‘wave function’ and force it to exist in a certain location and in a certain state. Example: Light is made up of packets of energy called photons. 

Quantum uncertainty/Heisenberg uncertainty principle (Copenhagen interpretation) 

A finding in quantum physics by Werner Heisenberg that states that one cannot know both the exact position and exact momentum (or velocity) of a single particle at the same time (certain pairs of physical properties cannot be known simultaneously to arbitrary precision). You can only measure the position of a particle or measure its movement but you can never find out both.

In order to know where something is, you must be able to see it – and to see an object you must shine light on it. Light is made up of packets of energy called photons which although tiny, do possess some mass. Because particles are so small, the photons that you have used to see where it is will cause it to move. So, although you have measured its position, you can no longer know its velocity. The very act of observing a particle changes its physical attributes, so we can never know anything about it.

Quantum superposition

The quantum mechanical property of a particle to occupy its entire possible quantum states simultaneously. Due to this property, to completely describe a particle one must include a description of every possible state and the probability of the particle being in that state.

Example: In quantum physics, any living thing could exist simultaneously in various states, from completely alive to dead and all stages in-between. All of these states, known as superposition are possible outcomes before observation is performed on the living thing.

Note: Time is a dimension which isn't linear. At quantum level, every moment, past, present and future, exist simultaneously. Therefore there is no paradox. It's just that 3-dimensional beings like us don't/can't experience time in this way. We experience it in a linear fashion.

Quantum non-locality/Quantum entanglement

This phenomenon means that once two particles interact together, they become forever ‘entangled’ and that whatever affects one will instantly affect the other – no matter the distances involved, even if they are separated by light-years of space. So by affecting the properties of the first particle, you instantly affect the properties of the second, making measurement of the second particle meaningless.

“All things are made of atoms — little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.” – Richard Feynman

In particle physics, an elementary particle is a particle with no measurable internal structure; that is, it is not made up of smaller particles. Elementary particles are fundamental objects of quantum field theory
  • Proton – A positively charged atomic particle that, along with the neutron, forms the nucleus of an atom.
  • Neutron – An electrically neutral atomic particle that, along with the proton, forms the nucleus of an atom.
  • Electron – An elementary particle with a negative charge that surrounds the nucleus of an atom and defines its chemical properties.
Protons and neutrons are each composed of three quarks.

Note: We tend to visualize an electron to be a tiny ball, in orbit around a larger cluster of balls representing protons and neutrons. That isn't what it is like. They don’t look like little balls. They are not like anything we recognize at all.

In Superstring Theory, each elementary particle is composed of a single string (each particle is a string), all strings are absolutely identical. Differences between particles arise because their respective strings undergo different resonant vibrational patterns. (Brian Greene)

All elementary particles are either bosons or fermions (depending on their spin). Spin is the intrinsic angular momentum of a subatomic particle. It is an important part of a particle’s quantum state. 

All the particles of the Standard Model have been observed (experimentally verified)except Higgs boson ("tentatively confirmed") and graviton (theoretical).

  • 6 ‘flavors’ of Quarks — up, down, charm, strange, top, bottom.
  • 6 ‘flavors’ of Leptons — electron neutrino, electron, muon neutrino, muon, tau neutrino, tau.

  • 12 Gauge bosons (force carriers) — eight gluons of the strong force, three W and Z bosons of the weak force, photon of electromagnetism.
  • Other bosons — Higgs boson, graviton.

Standard Model of Particle Physics 
(image taken from Wiki)

The Standard Model shown above explains the subatomic composition of the Universe and describes how three of the four forces stuck together (gravity is not included as graviton is not yet discovered). It explains how the Universe works at the subatomic level and is the basic understanding of matter for physicists.

Higgs boson and Higgs field

The Higgs Field is an energy field that exists everywhere in the universe. The Higgs field is not considered a force. It cannot accelerate particles, it doesn't transfer energy. The field is accompanied by a fundamental particle called the Higgs Boson, which the field uses to continuously interact with other particles. As particles (except the massless ones) pass through the field they are "given" mass. Different particles interact with the Higgs field with different strengths, hence some particles are heavier (have a larger mass) than others. (The Higgs particle does not interact with massless particles, such as a photon or a gluon. Since these particles don't interact with the Higgs field, the Higgs boson also doesn't interact with them.) The process of giving a particle mass is known as the Higgs Effect.

Elementary particle interactions 
(image taken from Wiki)

Note: Mass itself is not generated by the Higgs field - the creation of matter or energy would conflict with the laws of conservation. However, mass is "imparted" to particles from the Higgs field, which contains the relative mass in the form of energy. Once the field has endowed a formerly massless particle the particle slows down because it has become heavier.

Note: The Higgs particle, like many other elementary particles, is not a stable particle. Once the Higgs particle has been created, it will eventually decay. Since it interacts with all kinds of other massive particles it can be created in collisions. If the Higgs field did not exist, particles would not have the mass required to attract one another, and would float around freely at light speed.

Four fundamental forces-mediating fields
  • Strong Nuclear Force – Holds together the protons and neutrons inside the nucleus of an atom – and the protons and neutrons themselves. The strong force is the energy source for the Sun and nuclear power.
  • Weak Nuclear Force – Causes radioactivity and plays a vital role in the formation of the elements in stars and the early Universe. We don’t come into contact with this or the strong force in our everyday lives.
  • Electromagnetic Force – The long-range force much stronger than gravity, but acts only on particles with an electric charge. Electric forces between large bodies cancel each other out but dominate atoms and molecules.
  • Gravity – The weakest of the four, but a long-range force that acts as an attraction on everything in the Universe. For large bodies, the gravitational forces add up and can dominate all others.   

 The four fundamental forces of nature

The following theory is important to understand the third act of the film, Interstellar.

Unified Field Theory (UFT) - coined by Einstein, who attempted to unify the general theory of relativity with electromagnetism, hoping to recover an approximation for quantum theory and to bring four fundamental force-mediating fields (Electromagnetism, Strong and weak nuclear force and gravity) together into a single framework (a single field). In short, the theory attempts to reconcile quantum mechanics and Einstein’s general relativity.

Our preoccupation with matter itself is incredibly skewed. We have this tendency to think that only solid, material ‘things’ are ‘really’ things at all. ‘Waves’ of electromagnetic fluctuation in a vacuum seem ‘unreal’. Most people think that waves had to be waves ‘in’ some material medium. Unfortunately, no such medium was known or discovered. We are more like waves than permanent ‘things’. 

For example: An experience from your childhood. Something you remember clearly, something you can see, feel, maybe even smell, as if you were really there. After all, you really were there at the time, weren't you? How else would you remember it? But the reality is: you weren't there at all.
Not a single atom that is in your body today was there when that event took place…Matter flows from place to place and momentarily comes together to be you. All your body cells at that time are dead and replaced by newly-formed body cells every day. Therefore, whatever you are now, you are not the stuff of which you are made in the past.

Humans live in ‘macroscopic levels’ of space-time dimensions that are bound by the four fundamental forces. They travel relative to one another at slow speeds, generally unaware of the distortions in the passage of time and perceive time linearly.

Before quantum mechanics, it was generally thought that all knowledge of the World could be obtained through direct observation, that things are what they seem, as perceived through our senses. But, quantum mechanics have shown that this is not the case, by remarkably accurate at predicting events on microscopic scales, while able to reproduce the predictions of the old classical theories when applied to events on macroscopic scales.


  • Wikipedia
  • The Elegant Universe: Superstrings, Hidden Dimensions and the Quest for the Ultimate Theory – Brian Greene
  • The Grand Design – Stephen Hawking and Leonard Mlodinow
  • The Brief History of Time - Stephen Hawking
  • The Fabric of the Cosmos: Space, Time and the Texture of Reality – Brian Greene
  • Hyperspace: A Scientific Odyssey through Parallel Universes, Time Warps, and the Tenth Dimension – Michio Kaku



  1. Whoa..that's a lot to take in..for a science student like me..but nothing beats the curiousity..

  2. Holy Shit, that's a lot of info.
    Awesome stuff from Nolan, however these plot holes are hard to ignore: