Quantum computers are one of the trickiest but most colourful things to try and explain in the entire technology sector. What other technology is explained by talking about zombie cats that aren’t dead or alive until you look at them, spooky action at a distance, quantum-mechanical phenomena, superposition, and teleportation?  

We know from history that we just don’t have the imagination to anticipate where new information technologies can carry us.”  
John Preskell, Professor of Theoretical Physics


Let me start by stating that explaining today what quantum computing can be used for would be like explaining what electricity could be used for in the late 19th century. Back then we knew electricity could provide light, and we knew it would probably be a big thing, but could we ever have imagined the monumental impact it has had on our lives and our world? In 1880 you could ask someone to explain what electricity was, how it worked, and maybe even predict when it would be widely available, but if you asked what it would end up being used for, you’d probably get a very short list of uses related to factories and streetlights.

Quantum computing is an entirely new form of computing, I’ll repeat that, an entirely new form of computing. Not a better, faster, cheaper version of the computer your brought last year, not a 10 fold increase in speed, not a higher resolution screen, or more memory, this is completely different to any form of computer we know today. Maybe we shouldn’t even call it a computer as that limits our thinking. We should call it a quantum magic box. Because unless we think of it like that we won’t be able to imagine just how much we can do with it.

Just like blockchain, if you do a bit of reading on quantum computing you’ll find dozens of very well written articles explaining what it is and how it works. You’ll come away with an understanding of qubits, SQUIDs, superposition, entanglement and integer factorization. Well, you might if you can stay awake though all of that, but what you won’t get is an understanding of what they could do for us, and why we need them.

Although I’m dying to explain what a qubit is and how quantum entanglement works (no seriously I am) there are plenty of great articles that cover that, I’ve listed many at the end of this article. What I’m going to cover is what quantum computing could be used for, and why you need to start thinking about the implications of it now.

Step one though must be a very quick intro to quantum computing, so that you understand why they are so different from a computer of today. I’ll keep this simple.

What is a Quantum Computer?

I’ve got 99 Intractable Problems

A quantum computer is a tool that can solve intractable problems. Cool huh? Well only if you happen to suffering from a list of intractable problems that you really need solved, and only if you know what an intractable problem is. An intractable problem is something that can’t be practically solved by today’s computers (specifically it’s a problem for which there is no algorithmic solution). To solve an intractable problem using current technology means calculating millions of possible answers and then comparing them to find the best one. The more complex the problem, the more answers must be calculated, to the point that its well beyond even today’s most powerful supercomputers.

If you are a parent it will be very easy to understand the concept of intractable problems, here’s a common example:

Its Saturday morning, kids’ sports day. Your three bundles of joy all play different sports, all scheduled at overlapping times, at opposite ends of the city. All have at least one friend that wants a lift to and from the game, and you only have one car. How on earth do you get all the kids to and from their games without spending all Saturday playing taxi driver? Do you pick up Billy and go to soccer first, then get Sarah on the way to hockey, or start with Tim’s rugby then hockey then soccer, or try to squash them all in the car at once, and do you take the motorway or the backroads? Arrgggh. Sound familiar?

That’s a classic intractable problem, there’s a gazillion solutions to it, and all of them will get the kids to the games and back, but only one solution will leave you with the maximum time left in your day to do what you want to do. That’s called optimization.

A normal computer (these are now being called a “digital” or “classical” computer to differentiate them from quantum computers) can quickly solve parts of the problem, such as working out what route to take between sports fields to get their fastest, but that’s about where digital computers stop.

You see to work out the best possible solution to get you the most spare time in your Saturday a digital computer would have to calculate and compare every possible order of pickups, routes between pickups, order of dropoffs, etc. That’s likely to be millions of possible options, billions or even gazillions. Even if it only took a tenth of a second to calculate each one, a million options would still take 27 hours to calculate, and of course on the 26th hour Tim would tell you that he’s left his rugby boots at school and you’ll need to pick them up on the way, time to start those 27 hours of calculations all over again. Now you see how intractable and impractical are almost synonymous.

A quantum computer would calculate the best possible solution instantly (give or take a few seconds) by calculating every possible option simultaneously.

Calculating a billion possible combinations of possibilities simultaneously, sounds like magic doesn’t it?

For those of you that don’t have kids, and still sleep in until noon on Saturday (enjoy it while it lasts), you may be more familiar with this intractable problem:

It’s your wedding day, you’ve got 100 of your closest friends and relatives coming to your reception dinner and you need to work out the seating arrangements. Oh crap. You see Aunt Cersei hates Uncle Tyrion, who isn’t speaking to Great Aunt Daenerys, and your best friend has a crush on your other friend but doesn’t want to sit right next to them, they want another friend in between. The Lannisters can’t sit at the table next to the Targaryens, the Freys can’t sit between the Starks and the Tyrells, and the Greyjoys want two separate sets of tables due to an argument over the family boat. And of course, with only two days to go you’ve still got people RSVPing. Now sort out the seating plan so that no one will be unhappy about who they sit next to.

Go on, put that in an Excel spreadsheet and see if you can work it out.

A quantum computer would simultaneously calculate every possible answer to the problem, in an instant, and tell you the optimal answer (I’m taking a few liberties with the word instant, you should read that as very, very fast, almost instantly).

Sounds like Magic? How does it Work?

How does a microwave oven work? Who cares, it just does. So why do you care so much about how a quantum computer works, if it can solve your wedding day seating nightmare and give you an extra hour of peace on a Saturday does it really matter how it works? But then you wouldn’t be reading this if you didn’t care…

I’m not going to explain how quantum computers use qubits which unlike bits in a digital computer can be more than just a 1 or 0, they can be in a superposition in which they are simultaneously 0, 1, and everything in between. Then I’m not going to explain how quantum entanglement allow us to observe their state without destroying their superposition though decoherance. Nope, you don’t need to know that any more than you need to know how a transistor on a silicon chip works to understand that you can use a digital computer to read Facebook.

If you want to know how quantum computers work, check out the references at the end of this article (after you’ve finished reading my article of course). What I want you to focus on is the impact that quantum computers will have on you, your business, and society. Then you can start to plan and be ready to take advantage of the new technology when it gets here.

When will Quantum Computers get here?

Tuesday, July 19, 2023, 12:36pm GMT.  Give or take two years. Seriously, sometime within the next five years there will be commercially available quantum computers that can solve large intractable problems. Five years may seem like a long way away in today’s very fast-moving world, but when we get to the impact of what they can do, you’ll realize that you need to start planning for them now.

If we compare the current status of quantum computers to the development of normal computers, we are at the very start, it’s 1945 and there are one or two prototype computers made with vacuum tubes that take up entire rooms. That’s the almost current state of quantum computers, I say almost because back in 1945 vacuum tubes were a common component, the equivalent in a quantum computer is called a qubit and unlike vacuum tubes they are bloody hard to build and you can’t currently buy one.

From 1945 it took about 40 years until computers were common place on every desk, then another 15 years until they were in every home, and another 10 before they were in every pocket. I predict that the 65 years it took us to make digital computers ubiquitous will be slashed to just 6.5 years for quantum computers.

The 65 years it took us to make digital computers ubiquitous will be slashed to just 6.5 years for quantum computers.

Within five years from now there will be mainframe sized quantum computers available in the market. One and a half years after that we will all have access to quantum computers in the form of a smartphone. Nope, we’re not going to advance so fast that we can go from mainframes to smartphones in 18 months, we don’t need to. No one needs to carry around a quantum computer, you just need to connect to it via the cloud.

IBM and Google are already providing cloud based access to their prototype quantum computers so that people can start to understand what they could be used for.  In 6.5 years there will be apps on your phone that use the power of a quantum computer in the cloud to instantly tell you the optimal way to get the kids to and from their Saturday morning sports.

Now if the only thing quantum computing was going to do for us was help get the kids to sports or avoid a family feud on your wedding day, that wouldn’t be a big deal and you could put feet up for the next 6.5 years until it arrives. But that’s not the case, quantum computing will fundamentally change so many industries and activities that we’d better start preparing ourselves now, and hope that you really do have 6.5 years.

How will Quantum Computing Change the World?

The examples I used above seem a bit silly, why would anyone spend billions developing a quantum computer so that you don’t upset your relatives on your wedding day? They wouldn’t, but in 1945 we didn’t invent the first computer so you could play Candy Crush and watch videos of cats either. The initial purpose of an invention and its eventual uses often have nothing in common.

The initial purpose of an invention and its eventual uses often have nothing in common.

Quantum computers are being developed today to help with highly scientific research, but they will quickly be engaged for uses that today we can’t even imagine. I predict that we will see four key fields in which quantum computers will have a fundamental impact, those four areas are:

  • Optimization
  • Research
  • AI
  • The Unknown

Yes, the last one is a bit of a cop-out, but I wouldn’t want to limit your thinking to just the first three, and you may be able to imagine a use-case or impact that I haven’t so I don’t want three bullet points to frame your thinking.


Look around you, every industry, every job, every task that involves multiple factors has room for optimization. Think about airline flight scheduling, traffic light timing, staff shift schedules, the design of almost any product, macroeconomic modelling, even international diplomacy. All of these are running in a less than optimal way today, we cope with it, we accept it, but it could be better.

Imagine the life of a poor diplomat today trying to broker a trade deal, trying to balance the demands and needs of multiple countries, industries, workers, environment, indigenous populations, political parties etc.  Imagine if that could be modeled and the optimal solution provided instantly. No more five-year long trade summits trying to broker a deal, now it’s an instant everyone wins, benefits maximization answer whenever you need it.

Think about airline flight schedules, an incredibly complex area with dozens of moving parts, planes need to be scheduled to land when runways and gates are available, they need to line up with connecting flights, there needs to be the perfect number of passengers booked and waiting to catch the next flight, and it can all get screwed up instantly by bad weather. Even with the most advanced scheduling systems available today we might only achieve an 80% optimization.

Now imagine what happens when a quantum computer can work out a 100% optimal schedule of flights, that’s a 20% boost in efficiency. Do we then need 20% less planes? Or 20% less pilots, crew, and groundcrew? That’s not a small impact, that’s a major disruptor to the industry, and as an airline if you don’t embrace quantum computing to achieve 100% optimization you’ll be out of business as you carry a 20% overhead on your competition.


Look at some of the biggest investments in R&D today: pharmaceuticals, defense, biotech, and technology. How long does it take a drug company to develop and test a new drug? Typically 20 years and hundreds of millions of dollars, if not billions. Now what if a quantum computer could model the impact of the drug on every combination genes simultaneously to find the one that is 100% safe, or model every combination of drug on a particular illness to find the one that produces the optimal cure? You could cut down the R&D time for new drugs from decades to days. Imagine your doctor instantly creating on the spot a personalized drug that aligns perfectly to your DNA and illness.

One of the very first proposed uses of quantum computing was to model the quantum mechanical world (i.e. working out how things work at the sub-atomic scale). Today this is far beyond the reach of even the most powerful supercomputers, but it becomes possible with quantum computing. We wouldn’t need the Large Hadron Collider, we could just model the experiments. Our knowledge of the quantum world would takes leaps forward that we can hardly imagine. To discover anti-matter and the Higgs Boson wouldn’t need decades of building billion dollar elaborate physical experiments, we’d just run a simulation and have the answer.

Nuclear testing, everyone would agree that blowing up a nuclear bomb to see if a) it does blow up, and b) what happens when it blows up, is hardly the best thing for the planet. What if we could model the explosion rather than actually detonating a bomb?

Nanotechnology relies on understanding quantum systems, and such systems are impossible to simulate in an efficient manner with today’s computers, so quantum computers will give us a quantum leap in nanotechnology (sorry, I was dying to use the quantum leap pun). Now imagine the impact of that on the world when nano-machines are commonplace and easy to design.


Probably the fastest developing area of technology today is Artificial Intelligence. What seemed like science fiction a few years ago is now real, and the rate of development is still accelerating. However, the really exciting part, or scary part depending upon your views on AI, will happen once quantum computing is involved. The intersection of quantum computing and AI is being called quantum machine learning and quantum neural networks.

I’m quickly running the risk of not speaking in plain English as I touch on this concept, so I won’t start to explain what quantum neural networks are or how it is hoped that quantum parallelism or the effects of interference and entanglement can be used as resources to train neural networks, especially in big data applications. Let’s just put it like this:

Quantum computing is to AI as electricity was to the industrial revolution.

Yes, it is that important and game changing. The industrial revolution started before we had widespread electricity, factories had stream engines enabling machine based manufacturing, but it wasn’t until electricity became commonplace that the real revolution took hold. That’s exactly where we are now, AI is here and its creating a revolution, but that revolution will explode beyond our imaginations once we plug it into quantum computing.

If you are in the Elon Musk camp and fear the coming of Skynet this won’t be good news.


Just like electricity, telephones, computers and the internet all changed the world forever, so will quantum computing. That I can tell you with a great deal of certainty, what I’m less certain about is how exactly this will come about. Will the outcome be good or bad for us? Neither it will be a superposition, it will be good, bad, and everything in between all at the same time.

So start getting ready now, then we can use it to make the world a better place.

If you found this useful then have a look at some of my other plain English explanations:


As I mentioned, there are some fantastic resources out there explain what quantum computing is and how it works, here are the ones I found most useful:




Posted by Mike Bullock

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s