Quantum Physics Explained

Tearing down the mystique of quantum, and some thoughts on its future.

The start of the twenty-first century is an exciting time to be alive. A look at the start of the twentieth century juxtaposed to the end of shows how far humanity has come. The 1900s started without tea bags and ended with the discovery of nuclear power. Imagine what we can achieve by the end of this century! Whatever the twenty-second century brings, science and technology will definitely be at the forefront. Nonetheless, when we look a modern technology, it’s the same idea recycled or upgraded over and over again. Where are the hoverboards we were promised? So far, our technological
“advancements” have been nothing extraordinary. Yet, there exists a branch of science that can offer technologies we can’t even dream of. I’m not talking about a new app, a new phone, or even AI. I’m talking about a total game-changer that would revolutionize the way we think, operate, and gather information.

Without further ado, I present to you: Quantum physics.

Quantum has a mystique of being ridiculously complex. But what if it isn’t complex? What if you could learn the basics of it (and a bit more) at the end of this article? Well stop questioning and start reading.

What is quantum physics?
Quantum physics is a branch of science, used to describe small particles. It uses mathematical equations and theories to describe what cannot be seen by the naked eye.

Before we dive in there are two basic facts about Quantum that you should know:
1. All quantum particles have particle-wave duality

2. Quantum matter particles can be measured using a wave

Now this is a common misconception between a wave function and particle-wave duality

A wave function is a mathematical formula, this means that its existence is arbitrary, it doesn’t exist in the physical world. Quantum Physicists manipulate it to do calculations and determine numeric probabilities.

A wave function

A useful calculation is the probability distribution. By squaring the amplitude of the wavelength you can determine where the subatomic particle is located. The higher the point is the more probable it is the particle can be found there.

There is a high probability that the particle will be found where the arrows are pointed at. And a low probability that it will be found where the straight line is located.

All particles have a particle-wave duality that means they are both a particle and a wave. This can be demonstrated through the double slit experiment.

If you were to toss paint at the walls below, where do you think the paint will appear? The paint will likely be found predominantly on the first screen and directly behind the slits of the first screen, onto the second wall. But what if you were to do the same exact thing with electrons? Well, this is where it gets a bit odd.

The electrons would likely be found in locations like these, creating a striped pattern. This is due to the particle-wave duality.

The electrons move through the two slits like waves and overlap each other. When they overlap the probability distribution dictates that the electron will likely be found where the particles overlap.

Hence why the screen contains a striped pattern. Therefore, if you were to cover one slit, the electron would operate like the paint in the example above.

So why is it then that when you throw paint at the slits they passed through and don’t create striped patterns? Simply put, this is because the object is larger. Larger objects mean more stored energy and higher stored energy means high wave frequency. Objects with higher frequencies interact differently than objects with lower frequencies.

The above is a basic understanding of the quantum universe and can be applied to all particles. Although understanding it is critical quantum entanglement, superposition and tunneling is more key in developing future technology.

Quantum Entanglement
Quantum entanglements happen when particles generate or interact so closely that they can be described and measured as a single particle. For example, you have two electrons floating through space, when they collide the result is quantum entanglement, now these two electrons can be described using one wavefunction. When this happens, there are two electrons in this wavefunction, which is perfectly allowable and can be measured even across billions of miles.

Quantum superposition
Superposition is just a fancy word which means that two things can happen at the same time. For example, a particle can spin to the right and to the left at the same time. Another way to visualize it is by using a coin. If you flipped it there are two possibilities, right? Heads or tails. Wrong. In superposition both options happen at the same time, meaning that the coin is standing up.
Although superposition is complex to visualize and learn, it is a critical area in quantum physics.

This image is similar to quantum superposition. Two things are here at the same time, even though it is only one image.

Quantum tunneling
Picture this: you’re bowling and the ball comes in contact with a pin. The bowling ball knocks the pin over. But what if you were to bowl at the subatomic scale? At this point, you can probably guess something odd happens. Instead of the particle (bowling ball) hitting the barrier (bowling pins), it goes through. Quantum tunneling is when particles can move through barriers. Even though the wave decays if the barrier is narrow enough and the wave is strong enough, the wave can move through. A version of quantum tunneling happens every day. For example, when you
listen to music sometimes you can hear still hear outside noise, the sound wave moves through the barrier (your headphones, earbuds, etc) and even though it decays and is noticeably smaller you still hear it.

This visualize is technically incorrect. The particle decays when it tunnels,

Whatever the twenty-second century looks like I can guarantee you that quantum physics will be at the forefront. Quantum physics is an exciting and ever-expanding branch of science. It started with a simple theory of Nuclear power in just over half a century. Imagine what we could create in the next few years! You can be sure discoveries in Quantum physics will benefit society,
disrupt industries, and revolutionize mankind.

Artificial Intelligence, Deep learning enthusiast.