Quantum computing could be the biggest thing to happen to computers since their invention, because it fundamentally changes how computing works. Instead of just using ones and zeros, a quantum computer can use ones, zeros, and a special quantum state called superposition that is kind of like being both a one and a zero at the same time.
If you’ve looked into futurism in the past, you may be familiar with Moore’s law. It’s not actually a law, despite the name, just a trend people working in technology have noticed: the fastest computers avilable tend to get twice as fast roughly once every two years. (This means the cutting edge of what computers we can build, obviously. An already built computer won’t magically get faster.) The trend isn’t perfect, it used to be a bit faster, and in the past few years people have started to suspect the trend will disappear entirely by 2025. This is a big deal, because it means that all the recent advances in technology, the way computers have been getting faster and more capable, it all might end. We might be stuck.
Quantum computing has been posited as the next step in computer development, promising the possibility of continuing progress as fast as or even faster than Moore’s law has given us so far. You see, quantum computers are much, much, much faster than normal computers for some special, difficult types of computation. There are problems which would take one of today’s normal computers millions of years to calculate, if they ever could at all, that a quantum computer could solve in minutes.
But quantum computers aren’t miracle machines. They won’t replace normal computers, at least not at first, just add to them. Quantum computers only help speed up certain types of problems, like factoring large numbers, and don’t offer any significant benefits for other types of problems. Also, quantum computers are probabilistic, which means that there’s always a small but real chance that they’ll give you the wrong answer. These problems are things that computer scientists can work around, but it’ll take time to master quantum computing, even after we can physically build nice, high-end machines.
Some simple quantum computers do exist already, though. IBM unveiled the first commerical quantum computer just this year (2019). It’s nine feet tall and nine feet wide, and only processes 20 qbits (quantum bits, or the equivalent of 1 or a 0 on a quantum computer), which means it’s still just a very small first step compared to the quantum computers we want to build, but it’s still a huge milestone in the history of computers. Somewhat more powerful quantum computers such as the 79 to 160 qbit IonQ have been developed but are still not available commercially.
We’re still in the very early days of quantum computing, but we have a wild ride to look forward to. Here’s hoping computers continue to get more powerful for a long while to come!