We could be approaching a revolution in computing – yes, another one. Quantum computing is progressing with surprising speed. Right now it’s still experimental, but with the biggest tech companies in the world investing in the concept, it’s not too early to be amazed – or, if you prefer, terrified – by its potential.
What is quantum computing?
A radically different way of handling information. Regular computers represent the world in the form of binary digits, or bits. Each bit is a single piece of information, which can only ever be 1 or 0 (or ‘on’ or ‘off’ or ‘yes’ or ‘no’). Quantum computers are completely different. Instead of bits, they use ‘qubits’, or quantum bits, which can be between 1 and 0. For computers, it’s like going from black and white to colour.
How does it work?
In short, thanks to the weirdness of quantum physics. Like the cat in Schrödinger’s famous thought experiment, which was simultaneously alive and dead, qubits exist in what is known as a superposition of 1 and 0, so they’re somehow both 1 and 0 at the same time. What’s more, these quantum particles can be entangled, which means that they can be connected even at a distance. Einstein called this ‘spooky’ and didn’t believe it. But it seems to be true.
What does this mean in practice?
Because qubits can be both 1 and 0, they can contain far more information than classical computers: a single 100 qubit processor would in theory be more powerful than all the supercomputers in the world. But it’s the entanglement that really makes quantum computers like science fiction. If you change one particle, you change the other one too, so instead of transmitting data, you can transfer it instantaneously, as if it’s been teleported. That makes quantum computers unhackable, as well as lightning fast.
When will this be here?
It is already: Google, Microsoft and Intel have prototypes and, in July 2017, IBM announced it had built a 50 qubit machine. Researchers predict we’ll reach ‘quantum supremacy’, the moment a quantum computer beats the best classical alternatives, if not this year, then probably this decade.
What’s the catch?
The first is practical: qubits are extremely unstable (in IBM’s computer, the quantum state is maintained for only 90 microseconds), so it’s hard to make quantum computers reliable enough to use. The second concerns the implications. As well as securing data transfers, quantum computing could also break all regular encryption, without which the internet would cease to function as we know it. Entrepreneur Vivek Wadhwa recently called it ‘a Pandora’s box for security’.
Triumph or disaster?
In the end, it’ll probably be both at the same time.