### Quantum computers are coming

Quantum computing, which has been the subject of billions of dollars worth of research and theory, is a potential breakthrough in how computing is done today, and it holds the potential to greatly expand the capabilities of computing. However, there remain barriers to adoption, and it’s unclear how the field will progress. Furthermore, the very mathematics underlying quantum computers is difficult to fathom, even among those who understand the math and science well.

### Quantum Mechanics

Richard Feynman, one of the most insightful, and pithiest, quantum physicists, famously quipped, “If you think you know quantum mechanics, you don’t know quantum mechanics.” The field of quantum mechanics is what prompted Einstein to exclaim, “God doesn’t play dice,” a natural reaction to those first introduced to the field when first encountering some of its implications. Typical computers run on electricity, a force that can seem mysterious but that can be understood through analogies and a bit of education. Quantum computers, on the other hand, rely on a field that requires up wrap our minds around concepts that seem utterly unfamiliar and sometimes even a bit unsettling. Fortunately, one doesn’t need to know much about quantum mechanics to get a basic grasp on quantum computing. Being able to accept one concept, the superposition, means the rest of quantum computing falls into place.

Typical computers rely on bits, which are represented by ones and zeros. Using just these two numbers, our computers can solve any arithmetic questions and have excellent logic capabilities. Quantum computers, on the other hand, replace bits with quantum bits, or qubits. Unlike their binary counterparts, qubits can exist as both ones and zeros at the same time, in a so-called superposition. This isn’t an analogy: According to the most common interpretation of quantum mechanics, qubits are actually ones and zero simultaneously. With this capability, qubits are able to solve certain problems that are computationally expensive using binary arithmetic and logic in far fewer steps, and some problems can be solved with just a single step. Although the very concept of quantum computing sounds outlandish, devices are being developed by tech giants including Intel and Google, and Microsoft is already unveiling toolkits for developing software for quantum computers. Startups are having an impact as well, with companies including Rigetti Computing seeking to forge a role in the technology.

### Security Ramifications

Modern cryptography, which protects our passwords and keeps data encrypted, is based around using mathematics that are unrealistic to crack using modern computers. A strong encryption key, for example, might require something like the entirety of the world’s computation power working for millions of years to crack. With quantum computing, on the other hand, such security measures can be cracked in only a few steps. Developing new, quantum-proof security measures is difficult, and it means that virtually all data we assume to be safe from prying eyes may now be vulnerable to trivial hacking. The first government or military to develop robust quantum computing technology will have an incredible advantage over their counterparts still relying on traditional computing, and the advent of practical quantum computing will have tremendous geopolitical ramifications.

### Practical Uses

One of the most practical uses of quantum computing will be searching. Using a technique called Grover’s algorithm, quantum computers have the ability to search through databases and other collections of data far faster than using traditional search techniques, and this algorithm scales far better than classic searching techniques. As databases continue to grow in size, this improvement can make it more feasible to handle the large volumes of data expected to come online in the coming years and decades as we reach physical limits in storage device latencies. Another practical advantage lies in our understanding of the world. Simulating quantum effects is notoriously difficult using the computers we rely on today, as the very fundamentals of quantum mechanics are vastly at odds with today’s devices. Using quantum computers, simulating these effects will be far simpler, allowing us to better unravel the mysteries of quantum mechanics.

Even when quantum computing becomes common, it’s difficult to envision it completely replacing traditional computer devices. The types of applications at which quantum computers excel don’t seem to have much practical use for typical computer users. Furthermore, it will take some time for quantum computers to become smaller and more affordable, and there may be barriers preventing its widespread use. Perhaps home quantum computing will be a reality at some point, but very few people would see significant benefits from the technology as we understand it today. Still, it’s worth bearing in mind early predictions about traditional computers, as some people said the same about the computer architecture most of us carry in our pockets or purses as smartphones. However, with the uncertainty surrounding quantum computing development timelines, it’s probably best to avoid expecting the revolution to take place by a particular date.