Every year, computer chips get smaller, processing power jumps up massively in orders of magnitude, and all of the older tech gets that much less expensive. Compare a smartphone from today to one from ten years ago and you’ll see that this is slowing down, however. There have been diminishing returns in the last ten years that weren’t present in the years that preceded them.
The reason for this is that transistors are getting very, very small. So small, in fact, that we’re hitting the physical limitations of how effective standard computers can be. If transistors that can block electrons become small enough, something very weird and quantum-based can happen. The electron can use a property known as quantum tunneling to get past the transistor, thus rendering the computer useless as it can no longer control the electrical signals being sent through its components.
As such, this limit on how small computer components can get functions as a hard cap on how effective traditional computers can become. Much like the speed of light is a hard cap on how fast you can go, quantum mechanics offers a hard cap on how fast your computer can be. However, quantum physics also offer a clever solution to this problem: quantum computing.
In a normal computer, a bit is the smallest unit of information. It is either a zero or a one, depending on the transistor, and encodes the basic building blocks of computational arrangement. A quantum computer, on the other hand, would use a qubit, a unit even smaller than a bit, that could also be set to either zero or one. However, interestingly, qubits can also use the quantum property of “superposition,” a scenario in which it is simultaneously both one and zero at the same moment.
When observed, an object in a superposition collapses, becoming either one thing or the other. This could be used in computing to allow qubits to store vast quantities of information alongside one another, as they could maintain millions of configurations with just twenty qubits in a system. A qubit’s physical properties could be any observable phenomenon that a computer could interpret, such as magnetic spin in a field or a single photon.
This would allow computers with vastly superior processing power to become possible. The biggest effects of this would be greatly increasing the speed of processes like decryption. As such, this also means that eventual quantum computing poses a serious challenge for digital data security. Since these kinds of computers could crack normal encryption in a matter of moments, digital security experts will need to devise new ways to encode data to keep it safe from prying eyes.