Quantum Computing Explained
What is Quantum Computing?
Quantum computing is poised to revolutionize how the world works. It could have far reaching effects, impacting everything from technology to healthcare. Massive companies such as IBM and even the Chinese government have invested billions of dollars in its development. Google has recently claimed that they have achieved quantum supremacy – the first time a quantum computer has actually outperformed a traditional computer in a given task. But what exactly is quantum computing? And how does it work?
To understand how quantum computing works, one must first have a sense of how regular computers operate. Traditional computer chips function using ‘bits’. Bits behave like switches, either in an ‘on’ or ‘off’ position. When the switches are in the on position they are represented with a 1. When they are in the off position they are represented with a 0. Every program, app, photograph, or webpage you use consists of millions upon millions of combinations of these ones and zeroes.
While bits work well enough for most things, the issue with this type of computing is that it doesn’t reflect how things work in real life. In nature, things aren’t quite so binary. Life doesn’t function as simply ‘on’ or ‘off’, ‘yes’ or ‘no’. Real life is complex and uncertain. Computers hate uncertainty. Even the strongest, fastest supercomputers available don’t do well under uncertain conditions.
Over the last century or so, physicists have discovered that when you begin to examine how stuff works on the smallest possible scale, really bizarre things start to happen. They even had to develop an entire new field of science to explain what they were seeing. That field became known as Quantum Mechanics. The typical rules that govern how things move and work cease to apply once things are scaled down to the level of atoms and electrons.
Quantum Mechanics is the foundation of physics, which is the backbone of chemistry, which is the backbone of biology. So if scientists want a way to accurately and quickly simulate scenarios in those fields, they need a more reliable platform capable of handling this kind of uncertainty. This is where Quantum Computing comes in.
How Does Quantum Computing Work?
Rather than using bits like a typical computer, quantum computers use ‘qubits’. Unlike the switch-like functionality of bits, qubits exist in a state called superposition. Qubits in superposition exist in a state where they are both on and off at the same time or on a spectrum between the two. Imagine flipping a coin. When it lands, it will be either heads or tails. Now take that same coin and spin it. Until you check the coin by stopping it, it has an equal chance of landing on heads or tails. Superposition functions much like the spinning coin. It has the potential to be heads, tails, or something in between the two. That is what makes quantum computers so powerful, the qubits they run on allow for uncertainty because the computer itself can run in multiple states at the same time.
If you were to task a regular computer with finding its way out of a complex maze, it will run every single route in order, one at a time, and find the exit by a process of elimination. In contrast, a quantum computer would be able to run every single route in the maze at the same time, retaining its uncertainty until it completes the maze and finds the exit.
Another key function of the qubit is called entanglement. Going back to the coin example, flipping one coin would have absolutely no impact on the results of flipping a second coin. Their results are completely independent from one another. With quantum entanglement, particles are intrinsically linked together, even if they are physically separate. Once entangled, if the first coin lands as heads, the second coin will also be heads. It is, in essence, the lack of independence.
It sounds like something taken straight from the realm of fantasy, and physicists still don’t completely understand how or why it works. In the world of quantum computing, this means that information can easily be moved around, even if it contains uncertainty. That spinning coin (qubit) can be used to perform dizzyingly complex calculations at breakneck speeds. Stringing multiple of those qubits together in tandem allows the computer to tackle impossibly large and complex problems that would take the best non-quantum computers millions and millions of years to solve. It is the combination of entanglement and superposition that allows these massively powerful computers to perform numerous calculations simultaneously, thus accelerating problem-solving capabilities.
So, What Can Quantum Computers Actually Do?
Quantum computing isn’t only about making computers that do tasks faster or more efficiently. It’s about building a computer that will do things we could never even imagine tackling without them. The sorts of things the world’s most powerful supercomputers wouldn’t even be able to scratch. Even back in 2015, Google’s quantum computing project was claimed to be over 100 million times faster than its traditional counterpart at simulating annealing (splitting and recombining DNA).
Currently, supercomputers are capable of analyzing only the most basic of molecules. In contrast, quantum computers operate using the same exact quantum properties as the molecules they’d be simulating. This means that quantum computers should not have any issues handling even the most complex of simulations. Quantum computing will be invaluable for modeling and simulating chemical reactions, which are critically important for medical and pharmaceutical purposes. It also paves the road for quantum chemistry, which would greatly expand our understanding of molecular reactions.
The development of quantum computers could result in a host of improved products including things like more powerful batteries, stronger and cheaper pharmaceuticals, and more efficient solar panels. Other possibilities include improving fertilization formulas for increased crop yields, or even vastly enhanced carbon dioxide scrubbers to help the environment. There is even some speculation that quantum computing could be used to fully model reactions within the brain, potentially opening up treatments and therapies for a number of brain-related conditions such as Alzheimer’s or dementia.
Beyond healthcare, quantum computers have the potential to slingshot the development of artificial intelligence ahead by decades, if not hundreds of years. Google is already testing them to accelerate the progress of their self-driving cars. AI alone is predicted to increase productivity by more than 40% by 2035. Eventually, AI could be used to handle backend business tasks such as logistics, scheduling, data management, accounting, administration, communications, and document handling. It may not sound like a big deal for consumers, but the amount of time, effort, and money that could be saved across industries by offloading these kinds of responsibilities onto artificial intelligence is staggering.
Quantum Computers for Consumers
At this point you may be asking yourself when consumers will be able to get their hands on this kind of technology. Unfortunately, it is not very likely that you will ever get your hands a quantum laptop or smartphone. Personal quantum computers have been theorized about for decades but there is still much to be figured out before they could ever be a possibility. The reason why they are so difficult to make is because they are incredibly vulnerable to outside interference. This is why companies like Google keep their current quantum computers isolated in specially equipped labs away from any possible electrical interferences. Temperature also plays a significant role in how quantum computers function. They are kept chilled at near absolute zero, colder than outer space.
It seems researchers have figured out how to make quantum computers powerful and fast, but making them reliable and consistent has been significantly more challenging. This is why claims about massive accomplishments or leaps forward in quantum computing should be taken with a grain of salt. These accomplishments are done under tightly controlled conditions and are frequently problems that we already know the answer to. Despite how much work remains to be done, the reality is that quantum computers are here to stay. As the years go on, quantum computing will most certainly change the world -but for now the technology is not quite there yet.
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