Quantum computing is the latest and strangest development in supercomputers – computers that perform incredibly complex tasks. Science fiction author Arthur C. Clarke mused that “any sufficiently advanced technology is indistinguishable from magic.” Quantum computing is not magic, but dangerously close. It is based on two bizarre principles: superposition and entanglement.
Superposition involves probabilities. Classical computing is based on the binary system of of 0s and 1s. All computer code and electronic devices run on this system; if you go deep enough into the code, all you will see are 0s and 1s (called bits), and nothing in between. A bit therefore is the smallest unit in a computer program.
Quantum computing uses a special type of bit: a qubit. A qubit, like a bit, can have a value of 0 or 1. But it can also have both these values at the same time. This is superposition – the ability of something to be in more than one state simultaneously. We can’t know what state it is in until we observe it; until then, all we can do is assign a probability of it being in a certain state.
Entanglement is an even more bizarre aspect of quantum computing. It refers to the phenomena that if you were to measure a qubit, it changes what you see in another, no matter how far apart the two are. For example, if you see that the value of one qubit is 0, then the value of another entangled qubit billions of kilometres away becomes 1. There appears to be a mystical force connecting the two particles. Einstein called entanglement “spooky action at a distance”.
Quantum computing sounds like science fiction, but it is not. Companies including IBM, Google, Microsoft and Intel have built (or are developing) quantum computers. As with early classical computers from the 1930s and 1940s, quantum computers are beastly machines, with many wires and cables protruding in all directions. Additionally, they must operate at near absolute zero, (the temperature in outer space), about -273°C.
The potential applications of quantum computing are limitless. Because of their quantum nature, they will be billions of times more powerful than the most powerful supercomputers today. They will be able to solve problems or create applications that traditional computers simply cannot, including:
- artificial intelligence & machine learning – systems that can think, reason, and make rational judgments and recommendations, including medical diagnoses, farming and energy efficiency
- molecular modeling in chemistry and physics
- cryptography – creating unbreakable online security
- financial applications including investments,stock market and economic analyses
- weather forecasting
To recap, qubits (the building blocks of quantum computing):
- exist in many states simultaneously (superposition)
- are mysteriously connected together (entanglement)
Because quantum computing is attempting to discover the underlying principles of reality, it follows that these two principles should reflect reality, that is, existence should also be based on the fact that things:
- exist in many states simultaneously
- are mysteriously connected together (even when far apart)
At first glance, this seems absurd. Our everyday experience tells us that things exist in one state, and that if you change something, it’s not going to change something else, especially if it is far away.
But if we look closer, we can see that these are the same principles upon which the greatest and most pervasive technological innovation is based. It’s the technology that has changed the world more rapidly than almost anything else. It’s the technology that has toppled governments and powerful leaders, established friendships, solved mysteries while creating new ones and caused untold heartbreak, joy, sadness and everything in between. It’s the technology that you are using right now: the Internet. While the Internet does not represent all reality, it has come to represent and directly influence a large portion of it. It has become, quite literally, the “new reality”.
On the Internet, the same website appears differently for each user, depending on the device they are using. On certain sites, different information appears. For example, travel sites will present different prices depending on a user’s location, computer, previous queries and so on. This is superposition: the ability of the same thing to exist in different states.
Online, we are all connected, regardless of distance. When you do anything online (make a purchase, send a message, check your banking transactions, and so on), it makes no difference where you perform this action. Cyberbullying is based on the premise that sending a hurtful email or text has the same effect whether the sender is 5 metres from the receiver or 5,000 km. An action in one area affects another area – there are are no distances online.
It’s therefore no surprise that IBM has developed an online quantum computer. That is, a computer that is based on the principles of superposition and entanglement now exists on a platform that is based on superposition and entanglement.
The answer to the age-old question what is reality appears close at hand: probabilities and connections. The question now is what will happen after we’ve built computers that are millions of times more intelligent than us?
Will it lead to a utopia where all of the world’s problems are solved by benevolent machines? Or will we end up in an Orwellian nightmare, where heartless machines enslave humanity, or, worst still, we use machines to enslave others?
Place your bets, ladies and gentlemen. Place your bets…