Quantum computing

We might as well start the year with a really big, game-changing subject. Something that will bump productivity onto a completely different level, that will get us rethinking our relationship to things, and will either ensure our survival, or make it even less likely. Something that gets your head spinning enough to reach for an aspirin or a whisky, or at least encourages you to tie on your trainers and go for a stress-reducing run (New Year’s resolutions and all). Something out of science fiction that is very, very real. Quantum computing.

quantum computing

by Greg Rakozy for Unsplash

“Quantum” is itself an extraordinary word that implies both small and immense simultaneously. Quantum physics is about sub-atomic particles. Think of teensy hyper-microscopic atoms, and then divide that into its sub-parts. That’s quantum. Now, imagine a quantum leap, a huge advance or a big step forward, as in “a quantum leap forward for equality”, or “a quantum leap in the fight against cancer”. That’s also quantum. Like the word itself, quantum computing manages to straddle both extremes of the size spectrum while completely skipping the middle. It works at the teensy sub-atomic level. But its impact is almost of unimaginable size.

I promise to not get too technical, but some description of computing mechanics is required. Computers run on bits, that can be either 1 or 0. Put several bits together, and the resulting combination of 1s and 0s translates to a letter, number or symbol. A few of those gives you a word, an equation or a programming instruction.

Quantum computers don’t run on bits, they run on qubits. A qubit can also be 1 or 0. But it also can be both at the same time. This is the equivalent of encoding two classical bits into one qubit. However, this does not double computing power. It increases it exponentially. If one qubit contains the information of two classical bits, two qubits has four classical bits’ worth, three qubits has eight bits, four has sixteen, and so on. Exponential. That’s the exciting/scary part.

With quantum computing, calculations that today would take millions of years can be done in minutes. A quantum computer with even a modest number of qubits would be more powerful than anything that we currently have in existence. Chips with exponentially greater power will obviously give us a speed of computation that will make our current super-fast information highways seem positively clunky. And the limitations of computing power that hold back huge leaps forward will be blown away. The time required to sequence a genome, for example, could shrink to seconds, and make designer drugs affordable. Rapid analysis of the vast amount of information generated by ubiquitous sensors will lead to surprising insights and actionable conclusions about human motivation. Powerful sifting of data from outer space will make it easier to identify other bodies that could support life. Efficient and fast predictive behavioural analysis could decode stock market movements, ushering in a new form of finance and possibly even a new economic system.

With that much computing power on the horizon, the race is on to build the first working quantum computer. The front-runners in the corporate world are the usual suspects: Google, Microsoft, IBM and the recent addition of Intel. Outside the corporate world, the main superpowers are not sitting on the sidelines. Both the Chinese and the US governments are throwing vast amounts of money at the problem, and the UK, Dutch, Canadian, Australian and no doubt several other governments are also investing heavily.

A lot is at stake. The spoils of victory will be huge. But it’s not all good news.

Quantum computing raises the threat of artificial intelligence. Programming conversation and common sense becomes much more “human” at that level of power. The number of potential patterns in any exchange increases exponentially, along with the capacity to adapt the patterns to new inputs. Now, machine learning is based on drawing conclusions from vast amounts of data. With a quantum computer, the same conclusions could be drawn in a fraction of the time from a fraction of the data. Some see the development of artificial intelligence as an exciting tool. Many see it as a threat to our existence.

Modern cryptography would have to be completely re-written. The most widely used systems today rely on the difficulty of factorization of large numbers. Quantum computers could make those calculations in a matter of seconds, or even less. These cryptographic systems protect your emails, your online banking, your virtual currency wallets. They protect connected infrastructure installations, sensitive communications and military information. Obviously encryption would need to evolve along with the computing power. But such a fundamental shift will usher in a period of uncertainty as to how secure our online information is. The US National Security Agency is already warning businesses and institutions to get ready for the quantum threat.

The opportunity and the threat are not immediate, though. The most realistically optimistic predictions are a working quantum computer in 10 years or so. The most advanced quantum computer (that we know about) is the D-Wave, which some argue is technically not a quantum computer.

If we know how it works, why don’t we have working quantum models? In part because we don’t actually know how it works, we’re still figuring it out. But mainly because it’s very difficult. First, it’s expensive. Quantum computer prototypes are costly to build and maintain. For the superimposed quantum state (where both states of 1 or 0 are present at the same time) to appear and hold, the chip needs to be very, very cold, almost at absolute 0. And in total isolation, free from noise, light, or any other wave-like or atomic interference.

quantum computing

the D-Wave computer, photo by Kim Stallknecht for The New York Times

Then, there’s the problem of proving the results. In the classical world, we can measure things without affecting their state. In the quantum world, the act of measurement changes the measurement. The ways we observe and measure, which use light, an electronic charge or some other invasive instrument, affect the results. And even if we could interpret the results, how would we verify? Using a slow classical computer?

And once we’ve solved all those huge issues, having a working quantum computer will not be enough. New infrastructure, new operating systems and new algorithms will need to be deployed. Just the concept of writing code to harness the power of quantum magic in itself stretches the imagination beyond recognizable limits.

It does seem like magic. To grasp the idea of two opposite states existing at the same time, and giving us mind-bendingly fast computation power, requires a leap of faith in the gap between what we know to be true and what we observe. Just like any good magic act. We know that the dove was in the box, but look, there it is in the hat. As science fiction write Arthur C. Clarke presciently said: “Any sufficiently advanced technology is be indistinguishable from magic.” In this case, he couldn’t be more right.

In spite of the difficulties and the threats, the goal is worthwhile. What we could achieve is worth the risk. Getting there will push our collective intelligence into a new era. And the journey itself will open up tiny worlds. Going deeper into sub-microscopic matter will not only unleash the power that holds everything together. It will teach us more about the physics of the world we inhabit. And in so doing, we will not only reach new levels of information and insight. We will understand ourselves better.

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