# Quanta

“Anyone who is not shocked by quantum theory has not understood it.”- Niels Bohr

A quantum is the minimum amount of any physical entity involved in an interaction. For example, a photon is a single quantum of light. Quantum physics is the study of physics at the smallest possible scales- at atomic and subatomic levels.

This series was inspired by three books I recently read- The Theory of Everything, Black Holes & Baby Universes and Other Essays, and A Brief History of Time, all by Stephen Hawking. These paintings were done primarily to make quantum physics, which is something that can feel so abstract, unreal and intimidating, more visual and familiar for myself.

I mostly stuck to using the books I mentioned above for references and ideas, but I did end up reading a lot more fantastic articles and watching some really great videos aimed at laypeople, that I’m linking below:

I put these links up here because I didn’t want them to be at the end where they’re ignored. For real, if you’re interested at all in the paintings/ concepts which I’m putting down below, you must check them out!!

The illustrations are all watercolour, poster paint and ink on paper.

1. The Uncertainty Principle

Heisenberg’s Uncertainty Principle states that both the position and the momentum of a particle cannot be known accurately at the same time.

Werner Heisenberg derived the Uncertainty Principle from the Photoelectric Effect (for which Einstein won a Nobel Prize).

According to Heisenberg’s Uncertainty Principle, one cannot measure the state of a system exactly. The higher the accuracy by which you measure the position of a particle, the lower the accuracy by which you can measure its momentum, and vice- versa.

“To see where a particle is, you have to shine light on it. But Einstein had shown that you couldn’t use a very small amount of light; you had to use at least one packet, or quantum. This packet of light would disturb the particle and cause it to move at a speed in some direction. The more accurately you wanted to measure the position of the particle, the greater the energy of the packet you would have to use and thus the more it would disturb the particle. However you tried to measure the particle, the uncertainty in its position, times the uncertainty in its speed, would always be greater than a certain minimum amount.” – Stephen Hawking, Black Holes & Baby Universes and Other Essays

1. Quantum Foam

Small, ever- changing regions of space- time in which they are not definite, but fluctuate in a foam- like manner.

At very short length scales, or very high energy levels, it is expected that space- time will cease to behave like a smooth continuum, and that it would acquire a foam- like structure because of quantum fluctuations of the gravitational field. This is commonly called quantum foam or space-time foam.

“…matter is not continuous but is made up of atoms. Shortly thereafter, it was discovered that these supposedly indivisible atoms are made up of electrons revolving about a nucleus with energies of the order of a few electron- volts. The nucleus, in turn, was found to be composed of so-called elementary particles, protons and neutrons, held together by nuclear bonds of the order of 10^6 eV. The latest episode in this story is that we have found that the proton and electron are made up of quarks held together by bonds of the order of 10^9 eV.

…Our past experience might suggest that there is an infinite sequence of layers of structure at higher and higher energies…However, it seems that gravity should provide a limit, but only at the very short length scale of 10^-33 cm or the very high energy of 10^28 eV. On length scales shorter than this, one would expect that space-time would cease to behave like a smooth continuum and that it would acquire a foam-like structure because of quantum fluctuations of the gravitational field.” – Stephen Hawking, Black Holes & Baby Universes and Other Essays

3. Schrodinger’s Cat

Schrodinger’s Cat is a thought experiment devised by the physicist Erwin Schrodinger, that applies quantum theories to objects on a macroscopic level.

Imagine a cat locked in a box with a bomb that has a 50% chance of exploding within an hour. When one opens the box, the cat will either be found dead or alive. Logic tells us that before we open the box the cat was already in the state of being alive, or dead. But, according to quantum physics, before we open the box, the cat will be in the quantum state of being dead and alive at the same time.

Our active looking to see whether the cat is dead or alive forces nature into a decision, and the state of the cat collapses into either dead, or alive.

“The whole point of quantum mechanics is that it has a different view of reality. In this view, an object has not just a single history but all possible histories. In most cases, the probability of having a particular history will cancel out with the probability of having a very slightly different history; but in certain cases the probabilities of neighbouring histories reinforce each other. It is one of these reinforced histories that we observe as the history of the object.

In the case of Schrodinger’s Cat, there are two histories that are reinforced. In one the cat is shot (there are different versions of the experiment), while in the other it remains alive. In quantum theory, both possibilities can exist together.” – Stephen Hawking, Black Holes & Baby Universes and Other Essays

The Schrodinger’s Cat experiment questions the very nature of reality, so have a look at one of the videos I linked above if you’re in the mood for an existential crisis!

4. Quantum Entanglement

Quantum Entanglement is a phenomenon in which two or more particles are linked in such a way that the state of one has to be described with reference to the other.

So, if the spin (a physical property of particles) of one particle in a pair of entangled particles is down, the spin of the other will always be observed to be up, and vice- versa. The particles can be separated by a vast area of space-time, but they will always “communicate” instantaneously with each other.

For example, if two Schrodinger’s cats are entangled and one is found to be dead, the other will be observed to be alive.

Einstein called quantum entanglement “spooky action at a distance”.

5. String Theory

One of my favourite illustrations. At the heart of string theory is the idea that at some fundamental level, all the different forces, particles, interactions and manifestations of reality are tied together as part of the same framework.

String theory is pretty complicated for the average person to understand, so I’m pretty sure most of it went way over my head, but the Forbes article is really really good and makes for an interesting read.

Very briefly-

In string theory, point-like particles are replaced with one- dimensional strings. These strings can be “open”, or take the form of closed loops. On scales larger than the string scale, the strings look like ordinary particles.

These strings are vibrating, and the mass, charge, and other properties of the particle are determined by the vibrational state of the string.

6. The Higgs Field

Not gonna lie, even though I had a rough idea about the Higgs boson and Higgs field before I started this, I was really not prepared to feel as dumb as I did reading about the Higgs mechanism. The set of articles I read by Matthew Buckley (the link is above) was really good though and after about 8472894 readings of this excellent article in particular, I (sort of) understood how it works.

I’m not going to elaborate on how particles actually gain mass via the Higgs mechanism because it’s far too complicated to neatly and accurately condense.

The Higgs Field is a quantum field that permeates the entire universe. The Higgs field is crucial- it “gives” mass to all particles that interact with it via the Higgs mechanism.

The Higgs boson (also popularly called the God Particle much to the annoyance of Peter Higgs, who developed the idea of the Higgs field. He found the nickname too sensationalist.) is an elementary particle. It is an excitation of the Higgs field, just as the photon is an excitation of the electromagnetic field. Evidence of the Higgs boson was found at CERN (the European Centre for Nuclear Research) on July 4th, 2012.

So that’s the end of Quanta. I’m not sure I did each concept justice but I enjoyed myself thoroughly.

Tl;dr: Quantum physics is cool and you don’t have to be a physicist to enjoy it!!

For the less intense version you can visit my Instagram @sarahmodakart