Computing in the Now
Quantum Supremacy – sounds ominous, doesn’t it? Or maybe like a bad action film from the 80’s? Well really, it has to do with one of the most paradigm-breaking innovations in computing up to this point. For roughly 80 years, all of our computers have operated on the same basic premise: binary computations. Ones and zeros. Early on, this took the form of arrays of vacuum tubes. A given tube could be on or off, representing a one or a zero respectively (this is, by the way, what the symbols on a power switch mean).
Now, we use transistors – tiny circuit components that can trap a charge within them. The new AMD server CPUs have almost 40 billion of them, but the concept is the same. If the transistor is holding a charge, it represents a one, and otherwise, a zero. These ones and zeros, when combined, contain the information to recreate a letter or a colored pixel on your screen.
Keys to the Future
With quantum computing, all of that gets thrown out the window. It is based on quantum mechanics, which has revolutionized physics and chemistry over the past century. The most common scenario used to explain the basics of quantum mechanics is Schrödinger’s cat. Imagine a cat closed in a box with a flask of poison. You aren’t allowed to look in the box. So tell me, is the cat alive, or dead? Well, you don’t know. So say 1 is alive and 0 is dead. You’d have to give it a 0.5 right? Probabilistically, it is equally alive and dead at the same time. This is called a superposition of states.
But how can something be both alive and dead? It makes no sense, right? Just open the box and see… but at that point the superposition collapses and the 0.5 moves to a 1 or a 0. Or flip a quarter. We like to call “heads” or “tails”, but when it’s spinning in the air, it’s really both. Only when it lands does it become a head or a tail. But it doesn’t have to be 50/50. Maybe you think the cat is not very likely to drink the poison, so you would give it a value of 0.75.
This is how quantum computing works. Instead of storing information in bits, either a one or a zero, like classical computers, they store information in quantum bits, or qubits. They can be set to one or zero. But they can also be any superposition of states in between. This allows for a quantum computer to handle exponentially more possibilities than a classical computer and solve certain types of math problems that would otherwise take impractically long to solve, i.e. quantum supremacy. At least, that was the theory, up until last month when Google finally proved it with their 54-qubit Sycamore processor.
What to Look Out for
I’m sure you’re wondering what this means practically. Well, for now, not much. To prove quantum supremacy, Google chose a very specific problem that was designed to be easier for their computer to solve. Then they just had to show it solved that problem faster than any existing computer could. The problem was solved in 200 seconds, and Google claims it would have taken the fastest supercomputer in the world 10000 years. IBM, the owner of said computer, disputes this, saying it could have solved it in 2.5 days. Either way, the improvement is drastic.
But in the future, quantum computers could change everything. The large jump in computing power will likely disrupt a lot of spaces. We all use encryption for things such as bank account passwords. This cryptography protects information behind math problems which are impractical for computers to solve. Or, at least, they were. Cryptocurrencies are also based on similar algorithms. Mining bitcoin, for example, requires solving the next step in an increasingly complex math problem. If quantum computers were to start mining, they would flood the market with new coins, possibly breaking the crypto economy and putting all the classical miners out of business. You learn more about cryptocurrency here.
For now there may be a bit of a rocky road ahead, as this breakthrough will cause significant issues for existing systems. But we will adapt. We’ll come up with new forms of encryption, and make better cryptocurrencies. And we’ll be better for it when we come out the other end. AI will likely be able to take advantage of the sheer number of possibilities a quantum chip can handle, and start working on problems we thought impossible. Welcome to the age of quantum supremacy.