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The dangerous thing about being a quantum computing nerd—or aficionado, for those of us less prone to self-deprecation—is that, inevitably, an obvious question comes up. And that question is: “But what can a quantum computer do that a classical computer can’t?”

It’s a bit of a buzzkill question, to be honest. Not because quantum computing *can’t* do anything real-world-cool, but because our limited minds haven’t quite managed to develop algorithms that would be terribly useful for the advantages quantum effects might conceivably proffer. If this were a spiritual quandary, for instance, it would be akin to a human trying to wrap their mind around the concept of an omniscient, omnipotent deity. It’s hard because we don’t know what we don’t know.

In the very small realm of what we have currently identified as pertinent to quantum computing, quantum computers can work with a list of known algorithms at Quantum Algorithm Zoo. But that list, like another on Wikipedia, is a work in progress. One has to be comfortable delving into the realm of advanced mathematical systems—Oracles, as they’re called—which, as it turns out, is a bit of a limiting factor.

The current —and rather harsh—truth is that there aren’t really any real-world problems only solvable with a quantum computer. At least not right now. Anything we currently care about can most likely be solved on a classical computer if you give it a few million or billion years (and plenty of power). Not every computational nail needs a quantum-computing hammer. Katie Pizzolato, IBM QStart director, and William Hurley, founder and CEO of Strangeworks, a quantum computing startup in Austin, Texas, offered their thoughts on the current state of quantum computing.

## No Denying Quantum Computing’s Potential

We’re still in the early stages of quantum computing, and at least a few years away from being able to solve problems classical computers can’t, Pizzolato said, adding, though, that this didn’t mean people weren’t already trying. “We have more than 130 organizations representing Fortune 500 companies, academic institutions, research labs, government labs, and startups around the world experimenting with real business problems today on real quantum hardware,” she said.

The reason quantum computing continues to capture our imagination and generate so much interest is that its potential speed for solving a particular set of problems is still tremendously intriguing, even if we aren’t quite there yet. In theory, a quantum computer’s level of complexity means it could solve epic challenges across a plethora of industries, from pharmaceuticals to transport to infrastructure to finance and cybersecurity. This is because quantum computers are adept at factoring insanely large numbers and are good at solving mathematical puzzles such as the Traveling Salesman problem, which would quickly overwhelm a classical computer.

“I think the public will most likely miss all the wonder of quantum computing,” Hurley said. “They’ll be affected by it, but most likely not direct users and therefore will probably not be taken by surprise.” Hurley said a “killer app”-type algorithm for people to point to when discussing quantum computing abilities isn’t likely to be developed soon.

So, why even bother being passionate about it if it’s so hard to even come up with real-world problems to solve? Because a quantum computer can’t solve a big real-world problem doesn’t mean it can’t help in the process, Hurley said. Indeed, he believes that some of the computational complexities found in climate change and cancer research would be good candidates for exploration from a quantum computing perspective.

“While I’m not sure quantum will ‘solve’ either of them, I do think it will have a tremendous impact on the state of the art in both fields,” he said.

Pizzolato is optimistic about quantum computing’s impact on many areas of science and technology. “The ideas behind it are fundamentally innovative, and new ones are being constantly researched,” she said. Quantum researchers were incessantly “pushing the boundaries of what can be done with a quantum computer, and at the same time figuring out how it can affect the world we live in,” she said. Doing this, however, requires constant engagement with technology leaders in industries such as the financial services sector, energy, electronics, automotive, chemistry, healthcare, and airlines.

Over the next decade, Pizzolato has high hopes for things such as the simulation of new materials or drug discovery.

There are some problems for which quantum computers have a natural exponential advantage over traditional computers, such as the ones that are fundamentally quantum in nature, like quantum chemistry,” Pizzolato said. Machine learning was another good candidate for quantum computing acceleration, she said. “We expect more research to establish an edge on practical applications,” she said.

Just because the general public can’t see tangible results from quantum computing yet, doesn’t mean it doesn’t matter for real-life problems, Hurley said. “I think we see this in the billions of dollars governments are investing in quantum computing,” he said. “It’s a much bigger deal than people may think at first glance.

The U.S. recently announced a $1 billion (USD) quantum and artificial intelligence initiative, which includes $300 million toward developing new Department of Energy labs focused on quantum computing.

## Conclusion

Perhaps—much like Douglas Adams’ supercomputer ‘Deep Thought’ in “The Hitchhiker’s Guide to the Galaxy” whose answer to “the Ultimate Question of Life, the Universe and Everything” is 42—it’s not about solving for the questions we know how to ask, but asking the right questions that quantum computing can solve.

Because, do you know what a quantum computer *can’t* do? It can’t tell you whether it can do anything useful. And it might be for the creative among us to figure that out for ourselves.