Wonders of Quantum Physics: “What are Quantum Computers?” – Episode 3 (FOR BEGINNERS!)

In Physics, Quantum Physics, Technology by Mystifact

If you’ve heard of quantum computing; chances are you only know of them, but don’t know what they’re actually capable of doing. Most likely, this is because wherever you read about them, they’re vastly over-complicated and hard to understand. This article will help you understand the basics to a good degree, so hang on in there!

Quantum Computing

To understand quantum computing we must be familiar with some basics of normal, everyday computers. When you are able to compare the two; the contrast will really help you understand the strange world of Quantum Computers.


Classically, normal computers work with bits. When the signals of a computer are boiled down to their building blocks; all they really are, are 1’s and 0’s. The signal is either 1, or, 0. 1 is on, 0 is off. With a chain of these 1’s and 0’s you can produce a unique signal which performs a task for you in a computer.

As opposed to normal computers being either 1 or 0… quantum computers are both 1 and 0, at the same time. Imagine tossing a coin; where heads is 1 and tails is 0. The coin is either heads, or tails… right? But when you flip a coin, what is it when it is in the air flipping about? You could argue that it is both heads and tails. This is how a quantum computer generally works.

Instead of being called bits like in normal computers, they are called qubits; where the ‘qu’ shows we are talking about quantum bits.

How do Qubits work?

At this point you may be thinking; how does a system that can be both 1 and 0 at the same time, even make sense? It doesn’t… until we apply an analogy of some sort.

Normal Computers

Let’s take a 4 bit code from a normal computer. This means that the values this 4 bit code can take are:

0000, 0001, 0010, 0100, 1000, 0011, 1100, 0110, 0101, 1001, 1010, 1110, 1011, 0111, 1101, 1111

These are all the possible combinations of 0’s and 1’s for 4 bits.

Now imagine that one of these combinations is a password. If you ask a normal computer to find the correct password; it has to go through every single combination till it finds the right one – as you can imagine.

Quantum Computers

In a quantum computer, a 4 bit Qubit is ALL of these combinations at the same time. So if you ask it what the correct password is – you encounter the first problem of Quantum computing.

Referring back to the coin flip analogy; we established that when the coin is mid-air – it is both heads and tails. This means the password is in this Qubit combination, but you also have all the wrong answers mixed in at the same time.

This is one of the main problems in Quantum computing; as soon as you ask it for a definitive answer – it doesn’t know what to do and crumbles. What can be done about this?

The Grove Operator

In simple terms, this removes the wrong password combinations, and chooses the correct one to be processed as the answer – showing you how much faster quantum computers are [2]. In fact, let’s apply this on a larger scale.

In real life, encryption is how data transmission is kept safe. It would take a regular computer millions of years to crack and decrypt these codes – some codes may take the computer the lifetime of the Universe to crack. With quantum computing; it could take a matter of seconds due to the way Qubits work.

Google maps is another good analogy. When you enter your destination, a normal computer goes through every single route and consequently chooses the fastest one for you. In quantum computers, they would instantly know the fastest route. To extract this route you would use the Grove Operator.

Self-driving cars are slowly becoming implemented into our culture; so now, imagine a master quantum system that could control where all these cars went, for the fastest route possible – one that could also control when traffic lights turned green or red for maximum safety. Do you see how great these systems could be?

What if we could give a quantum computer the ability to reprogram itself? That would mean it could choose the best combinations of code for artificial intelligence. Slightly scary thought, don’t you agree!

While they can be great, they can also be terrifying. The future of innovation in technology is uncertain and will happen in the next 50 years. Who knows, maybe computers will one day take over the world! Hopefully, you now understand the basics of Quantum computing, and are able to explain it to others.

Enjoyed this introduction, but want to know more? I strongly recommend this book. It builds on what I have explained in this article, and in general, teaches you about almost all principles to do with Quantum Computing!

If you have any questions, leave them below and until next time, take care.

~ Mystifact

[1]: https://www.cl.cam.ac.uk/teaching/0910/QuantComp/notes.pdf
[2]: https://en.wikipedia.org/wiki/Grover%27s_algorithm

Please note; no copyright infringement is intended. All images used have been labelled for re-use on Google Images. If any artist or designer has any issues with any of the content used in this article, please don’t hesitate to contact me to correct the issue.

Previous ‘Wonders of Quantum Physics’ Episodes:
Wonders of Quantum Physics: “What is Light Made Of?” – Episode 1
Wonders of Quantum Physics: “What is Matter?” – Episode 2

I strongly recommend reading episode 2 “What is Matter?”. It makes you think!

Previous articles you may have missed:
Can We Download Our Brains and Live FOREVER
What happens to you in Space without a Spacesuit?
The Science of Tanning: What does the Sun do to your Skin?

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