By Ivan Handler

Special to the OUL

June 16, 2023 – There has been a continuous stream of extremely impressive technical advances in the world ever since the closing days of WWII. The invention of the computer was in many ways the most significant since almost every other advance has depended on the computer and its amazing evolution post war. But add to the computer, nuclear weapons, the transistor, the discovery of DNA, the Internet, CRISPR and you see how completely scientific discoveries have profoundly impacted society.

It looks like quantum computers are going to be the latest advance with many far flung applications that are just starting to appear.

But along with new technology comes a lot of speculation and especially hype. Hype plays a special role since it takes lots of resources to develop technology which means investors need to be convinced of its profitability and government agencies need to be brought onboard the bandwagon. Hype generates excitement, and in the US, excitement appears to have magical powers over investors. For example, remember “Pets R Us” and the thousands of failed, ridiculous internet startups in the late 90s.

The new book, Quantum Supremacy, fits into this scenario neatly. It is written by a prominent physicist who is an excellent expositor of both the technical details behind quantum computing as well as someone with broad knowledge of many areas of science and engineering. This allows him skillfully to hype the implications of quantum computing (QC) to the public, especially potential investors.

First of all, despite the hype, a reader will learn a lot about quantum mechanics, quantum computing, and many other areas of science when reading the book. The writing is clear, concise, and enjoyable. It is worth reading for those reasons alone. Kaku isn’t that clear about how these computers function because, at this point, you need to know a lot about quantum mechanics to understand much more. That really shouldn’t be a problem for the average reader.

The problems I have with the book are with Kaku’s unfortunate ignorance of what is happening in agriculture and the relationship with many of the technologies and projects related there, such as the invention of fertilizer and the green revolution. It is significant that Kaku mentions global warming and a bunch of possible technical approaches to reducing greenhouse gasses and ignores the crisis in biodiversity[1] which includes warming and much more and is far more serious.

In general, there is a difference between what we can do with technology and what we should do. Kaku is high on the former and human survival depends on the latter.

Chapter 1

Kaku starts with some announcements of quantum computers that have accomplished remarkable results: Google’s ‘Sycamore’ quantum computer could solve a mathematical problem in 200 seconds that would take 10,000 years on the world’s fastest supercomputer. The Quantum Innovation Institute at the Chinese Academy of Sciences went even further. They claimed their quantum computer was 100 trillion faster than an ordinary supercomputer.”

This chapter touches on the themes in the book without much detail. While Kaku mentions that quantum computers are not like the current programmable ones, he gives the reader the impression that quantum computers will replace current computers because of their computational abilities. This is not true. So far, quantum computers are attacking many problems. But it is not at all clear that there aren’t many problems that can’t be solved by quantum computers that are solvable by traditional ones. This is an aspect of the hype that continues throughout the book.

The heroes of this chapter are Big Tech: Google, Microsoft, Intel, IBM, Rigetti and Honeywell. This excites Wall Street and someof its projections: “… that the market for quantum computers should reach hundreds of millions of dollars in the 2020s and tens of billions of dollars in the 2030s.”

He does mention on page 6 that: “Despite the impressive technical achievements made by Google and others in recent years, a workable quantum computer that can solve real-world problems is still many years in the future.” Kaku probably should have put this disclaimer in each subsequent chapter.

He then mentions that Richard Feynman, a Nobel Laureate, wrote a groundbreaking paper in 1959 that directly led to quantum computing. He then sketches the idea of a qubit and how it replaces the ‘bit.’ The ‘bit’ in standard computing has a value of ‘one’ or ‘zero,’ the basis of binary coding. The qubit, drawing on the varying states of atoms and their electrons, can have vastly more values than ‘one’ or ‘zero’ on the quantum level. Hence the ‘q’ is added to ‘bit,’ making the qubit. Thus, the phenomena of numerous superpositions on the atomic level make using qubits in calculations quite powerful. The rest of the chapter previews how Kaku sees quantum computing impacting other areas of society. Each description of a fantastic outcome comes with little else than his enthusiasm.

On the other hand, on page 18, under his Feeding the Planet headline, he lauds the green revolution as well as Microsoft’s attempts to improve fertilizers with quantum computing. This is quite sad since the green revolution did more to feed dogs and cats than it ever did to feed people – see How The Other Half Dies by Susan George published in 1977. The environmental damage done by fertilizers is well known and is one of the main reasons people turn to organic agricultural practices.

Chapter 2

Here Kaku does a great job recounting the development of computing technology from the Ancient Greek Antikythera mechanism (and the thinking behind its calculations) through the work of Alan Turing on the formalization of computing. Even here, there is a certain amount of hype. “While the Antikythera represents the beginning of computer technology, the quantum computer may represent the highest stage of its evolution” Too bad he didn’t add the word ‘today’ at the end of that quote. It should be clear reading this chapter that the quantum computer, for whatever its promises and perils, is just another step down the road of scientific innovation. (CONTINUED)