How to finally get a grasp on quantum computing

Quantum computing seems to be in the news quite often these days. You’ve probably seen quantum chips gracing your streams and their strange, steampunk-style cooling systems in the pages of magazines and newspapers. Politicians and business leaders are also peppering their announcements with the word “quantum” more frequently. If you’re feeling a little confused about all of this, this is a good year to make a New Year’s resolution to finally understand what quantum computing is.

This is an ambitious goal, and the timing certainly makes sense. The quantum computing industry has seen many scientific achievements over the past year, and the field is now worth more than $1 billion – a figure expected to double over the next two years. But wherever there is money and growing interest, there is also bound to be a lot of hype.

Many questions remain about when and how a quantum computer will be able to outperform conventional computers. Mathematicians and theorists may be able to answer some of these, but our best bet might be to simply build better quantum computers and, well, play with them. But even that isn’t easy: There is no broad consensus on how to build a better quantum computer.

Worse still for those curious about quantum computing, quantum mechanics is truly difficult to understand. Physicists still disagree on exactly how we should make sense of strange quantum phenomena like superpositions or entanglement. Yet it is precisely these strange properties that constitute the crucial ingredients of quantum computing.

If this seems insurmountable, you are not alone. But I think these obstacles are not insurmountable. Just look at the children.

I was a high school teacher and there were always a few students in my classes who would hang out after class to ask me surprisingly technical questions about quantum computing. They were curious, and that was enough for them to learn enough to ask big questions, even when their mastery of math and physics was not exceptionally advanced. One year, a student approached me after taking an online quantum computing course over the summer, just for fun, and he actually knew more about writing quantum computing code than I did! We spent the next year studying lessons that I otherwise would have taught only to students.

A few months ago, I met another quantum knowledge seeker who was starting young. Kai, a 9-year-old YouTuber, co-hosts a podcast called The Quantum Kid, where he asks questions about quantum computers to some of the world’s leading experts while more than 88,000 subscribers watch and learn alongside him.

Kai’s co-host is his mother, Katia Moskvitch, a physicist with a long career in science writing. Moskvitch works at Quantum Machines, a company that builds conventional computing devices that help quantum computers actually work, so she’s no stranger to the industry. Kai brings a lot of curiosity and enthusiasm to the podcast, and he has the great privilege of asking questions of people who have played important roles in shaping our modern ideas about quantum computing.

Peter Shor formulated the most famous quantum computing algorithm and joined the podcast to talk to Kai about what quantum computers could have to do with improving sustainability and fighting climate change. Nobel laureate and former US Secretary of Energy Steven Chu makes an appearance in the same episode. Computer scientist Scott Aaronson, an influential expert on quantum computing algorithms, talks with Kai about whether quantum mechanics allows time travel and whether even such a fanciful idea could, in theory, have any connections to quantum computing. John Preskill, another physicist whose work has influenced how we measure the success of quantum computers today, comes to discuss quantum computing and robotics alongside roboticist Ken Goldberg.

To be clear, The Quantum Kid won’t necessarily provide you with rigorous mathematical knowledge about quantum computing, but it’s a good start and a charming way to hear from some of the biggest names in the field. Most episodes cover the basics of quantum mechanics, like superposition states or Heisenberg’s uncertainty principle, but to really understand them in detail, I would recommend further reading, perhaps in a publication like New scientist.

The value and charm of The Quantum Kid is that Kai asks exactly the questions you might ask if all you know about quantum computers is that they are somehow special and potentially very powerful. In other words, if you’ve decided to finally understand quantum computers but feel like you don’t know anything, Kai is here to tell you to be curious and ask questions anyway. (I’d also be happy to guide you through the tricky world of all things quantum.)

Can quantum computers help us explore space or travel to the past? Can they help us make smarter robots and fight climate change? Will we one day use them to improve aerial navigation or create materials that currently seem like a fantasy? The answers to these questions are complex, nuanced and full of uncertainty. Explaining this to an excited 9-year-old requires clarity and kindness, which viewers of The Quantum Kid also benefit from. I loved hearing Peter Shor repeatedly say that existing quantum computers are, by and large, not powerful enough to change the world without completely dampening Kai’s enthusiasm.

In the first episode, physicist Renato Renner tells Kai that “you’ll grow up with a new machine that can potentially do new things, and you need to think about how to use it”, which gives the podcast an optimistic, forward-looking tone that is echoed by many of its guests.

It’s also the right attitude to bring into any quantum learning project you might undertake this year – a blend of Kai’s enthusiasm, imagination and curiosity and the deep, nuanced expertise of his guests. Quantum computing is complex and full of caveats, but that speaks to its novelty, and what could be more exciting? And if a 9 year old can taste it, you can definitely try it too.