What is Quantum Computing?

What this episode covers

From Short and Sweet AI, I’m Dr. Peper and today I’m talking about one of the most challenging ideas I’ve ever discussed, quantum computing. Quantum computing excites and perplexes me. It has all these strange, science fiction parts to it such as superposition, entanglement, parallel universes, yes, I said parallel universes, temperatures as cold a deep space, well, just above absolute zero really, and of course qubits. And quantum computers have been described as looking like steampunk chandeliers. Quantum Bits = Qubits Let’s start with qubits. In traditional computers, information is coded as binary units which are either ones or zeros and referred to as bits. They’re like tiny switches that can be either in the off position, represented by a zero, or in the on position, represented by a one. Computers are made up of millions of these bits in some combination of ones and zeros. This binary system is how our phones, apps, websites and the internet work. Quantum computing is completely different. It involves a philosophical leap really. It involves the idea that a single object can be in two states at the same time, so it can be a one and a zero at the same time, or it can be on and off at the same time. I know, it sounds crazy. Superposition Take a coin for example, if you flip a coin, it can be either heads or tails. But during the flip, the coin is spinning and is in both states at once, heads and tails at the same time. This is called superposition. Quantum computing stores a combination of one and zeros in both states, on and off, at once, in the form of qubits. Quantum computers are powered by collections of qubits in superposition and that’s what makes them so powerful. Entanglements The other thing qubits do is called entanglement. When two particles are linked together in quantum computing it’s called entanglement even if they’re physically separate. Normally when you flip a coin, tossing one coin won’t affect the next coin toss. But in quantum computing, two spinning coins can be linked together and if one comes up heads, the other one will also come up heads.Then if you can string together multiple qubits you can tackle the problems that even our best computers can’t solve. But quantum computers are not really just about doing things faster or more efficiently. They can do things we can’t even dream of, things our everyday supercomputers can’t possibly do. Light Bulb, Not Candle A quantum physicist, Shohini Ghose, says a quantum computer is not just a more powerful supercomputer just as a light bulb is not a more powerful version of a candle. You cannot build a light bulb by building better and better candles. A light bulb is a different technology just as quantum computing is a different technology. Having a lot more candles won’t achieve the same effect of what a light bulb can do because they’re two different technologies. And just like a light bulb transformed society, quantum computers have the potential to impact many, many different aspects of our lives. Magic Quantum computing is so strange, so futuristic, so exuberant, really, I love it. To me it’s what the science fiction guru, Arthur C. Clarke, was thinking about when he said, “any sufficiently advanced technology is indistinguishable from magic.” There’s so much more to discuss about qubits, quantum computing, and the space race to quantum supremacy in my next episode. Until then, from Short and Sweet AI, I’m Dr. Peper.