Quantum — For Dummies
By Justin Wang
In lieu of recent advancements in “quantum computing,” “quantum,” in many cases, seems like one of those words that scientists put in front of something to make it seem seven times more complicated — part of the club with descriptors like “prehensile” or “omnidirectional.” Yet, the question keeps popping up: what does “quantum” mean? And how is it used to make our beloved computers obsolete?
The dictionary definition of quantum reads as a discrete or allowed amount, either in the form of energy or monetary damages. It still doesn’t shed any light as to why scientists are so stumped on how particles can flit about like hummingbirds, or how teleportation of information across millions of miles can work instantaneously. So, what does “quantum,” when looking at quantum mechanics, really mean?
Quantum mechanics is, at its most basic level, is the science and study of the behavior of subatomic particles. And this behavior, which has puzzled physicists for decades, makes no sort of sense. Particles can be in two places at once, modelled as waves or as singular points of energy, or spin one way only to spin another way when you blink twice. But, at its core, quantum mechanics centers on one topic — superposition, defined as the ability for something to be unknown until observed. The textbook example of quantum mechanics is Schrödinger’s cat — a cat, put inside a box with a radiation source, that has a 50% chance to perish and a 50% chance to stay cute and cuddly and ready for internet fame in cat videos. Before we open the box, it is theorized that the cat is both alive, and dead, at the same time; at least, until we observe it and force a possibility to become reality.
Yes, it’s confusing — and yes, it’s still not fully understood, but this concept is now being expanded past the theoretical stage into quantum computing. Google’s new quantum supercomputer — dubbed Sycamore — has just recently surpassed calculations that would take normal supercomputers exorbitant amount of time.
But the mechanisms of how Sycamore accomplishes this are much more complicated and uncertain than that of normal supercomputers. Normal computers use bits — simple on or off signals — to do calculations. Quantum computers use qubits: signals that can either represent off, on, or off-on at the same time. This superposition, where the qubit isn’t certain until its observed, just like the cat, means that the same signal that would take an exorbitant amount of time can be cut by a huge margin. Entanglement — the particle equivalent of splitting a glove into 2 different boxes, then opening up a box with a left glove and realizing that the other box must have a right glove — along with other quantum shenanigans cut down calculation time even further, and promise to make quantum computing the next frontier of computer science. In the far future, qubits serve as the next step in making Siri self-aware with the power to predict our every move. A comforting thought, don’t you think?