What is a Quantum?

Today the science world is full of the word quantum - quantum physics, quantum optics, quantum chemistry, quantum gravity, quantum computer, quantum electronics, etc.. Its gotten to the point where it’s rather hard to find a scientific branch in which the word isn’t used!

But do you actually know what the word quantum means?

It’s actually quite simple to understand! Let’s start with it’s origin: it comes from the Latin word quantus which means how much. Pretty easy so far, right? If you need some help remembering, the word quantity comes from the same word!

Now here’s the explanation: Imagine cutting a loaf of bread in half. Then you cut it’s half in half. Then you cut it’s fourth in half, and so on, and so forth. Would you be able to continue on cutting it into smaller and smaller pieces forever? (We are using a very, very sharp and thin knife that can cut crumbs, our knife has no limitations in this scenario, it can cut anything we want it to.)

The obvious answer is no, you can’t, because that would mean our loaf of bread would be made out of an infinite amount of something. Your bread is finite, it has a specific mass, you can eat it all up! That means we can reach a limit - a certain “crumb” that is so small it can’t be divided anymore, and that all the other crumbs and halves and loaves are made up of it.

That “crumb” is called a quantum. A quantum is the smallest amount of physical quantity that can exist independently.  Basically, it is the smallest unit, the one brick, the one LEGO out of which everything else is composed.

So quantum mechanics is the science of the mechanics of the smallest units of the universe, quantum optics is the field of research that deals with the smallest units of light, quantum tubes and dots are tubes and dots that are made out of the smallest units.

Obviously most of the fields of study that use quanta(the plural form of quantum) are very, very complicated and difficult to understand, and this post is in no way a reliable source of information on these subjects! If you truly wish to learn about them you should apply to a physics department of your university, as it take years of studying under proper professors to fully grasp any of the listed fields of research!

This post is just my attempt to enlighten the casual reader on what that fancy sounding word that everyone tacks on to normal words means. I hope I’ve succeeded in this, and cleared up some confusion!

P.S. Please note that this is applicable only to physical property! This is because physical property is actually made up of something physical - in math, on a purely theoretical plane,  we can easily make up a number out of infinite parts:1=1/2+1/4+1/8+1/16+1/32…. This is because numbers are theoretical, and don’t exist in the real world! You can have one of something, you can write or draw or express the number one, but the actual number one doesn’t exsist! You won’t find it anywhere in the universe!

P.P.S. If you actually have a degree and/or know your way around the field of physics and my explanation sounds familiar - it should. Ancient Greek philosophers have formulated this explanation(minus the vocabulary) way waaaaaaay before me, and, unlike me, they did it based purely on logic, which is a lot more impressive.