What does quantum computing have in common with the Oscar-winning movie “Everything Everywhere All at Once”? One is a mind-blowing work of fiction, while the other is an emerging frontier in computer science — but both of them deal with rearrangements of particles in superposition that don’t match our usual view of reality.
Fortunately, theoretical physicist Michio Kaku has provided a guidebook to the real-life frontier, titled “Quantum Supremacy: How the Quantum Computer Revolution Will Change Everything.”
“We’re talking about the next generation of computers that are going to replace digital computers,” Kaku says in the latest episode of the Fiction Science podcast. “Today, for example, we don’t use the abacus anymore in Asia. … In the future, we’ll view digital computers like we view the abacus: old-fashioned, obsolete. This is for the garbage can. That’s how the future is going to evolve.”https://embed.podcasts.apple.com/us/podcast/fiction-science/id1528078321
Computer scientists might take issue with Kaku’s digital doomsaying — but there’s little doubt that quantum computers will transform the field as much as artificial intelligence is transforming it today.
“Quantum computing could very well revolutionize what an Amazon Web Services or Microsoft Azure will want to do for the world in terms of computing,” says Louis Terminello, associate laboratory director for physical and computational sciences at the U.S. Department of Energy’s Pacific Northwest National Laboratory.
Kaku’s assessment of the potential impact goes a lot further: In his view, any problem that involves sifting through a multiverse worth of possibilities will become more solvable once the quantum revolution takes hold. Energy generation and storage, food production, climate modeling, disease treatment and genetic repair are all potential targets for quantum supremacy.
Why is that? In contrast to the rigid one-or-zero approach that serves as the foundation of classical computing, quantum computers would take advantage of the fact that quantum bits — better known as qubits — can represent multiple states when information is processed.
“Quantum computers, in principle, are infinitely more powerful than a digital computer that computes on zeros and ones, zeros and ones, because quantum computers are quantum mechanical,” he said. “The atom can spin in any direction. How many directions are there? An infinite number of directions.”
Tech titans haven’t yet settled on the best basis for quantum computing: Amazon, Google and IBM use superconducting circuits in their hardware. IonQ — which is creating a research and manufacturing facility in the Seattle area — favors a technology based on trapped ions. Other companies are taking advantage of the quantum properties of photons, or defects in silicon lattices. And Microsoft is placing its bets on topological superconducting nanowires.
Which technology will win out? Kaku says it’s too early to tell.
“How many quantum computer architectures are possible? An infinite number of them,” he says. “Now, of course, only a handful of them are practical and economical. But the point I’m raising is that Mother Nature has already devised millions of quantum mechanical systems, and we’re playing catch-up to Mother Nature. And so I think that one day, one or or a handful of these technologies will dominate the whole field, but we’re not sure yet.”
Even though full-fledged quantum computers aren’t yet ready to prime time, researchers are already trying to figure out how to simulate the quantum mechanisms behind important biological processes such as photosynthesis and nitrogen fixation. Coming up with new molecular methods to perform those tasks could be worth billions of dollars.
“About 1% or so of the world’s energy goes to the process to refine nitrogen in the air to create fertilizer,” Kaku says. “But it’s very wasteful. … We need a quantum mechanical Green Revolution.”
Kaku says chemistry is a prime target for the quantum revolution.
“Chemists who do not use quantum computers to model chemical reactions will go bankrupt,” he says. “They’ll be out of a job. They’ll be replaced by chemists who do use quantum computers. This means all medicine. All medicine can eventually be reduced to a quantum computer.”
Once quantum computers take hold, researchers could design synthetic molecules for medicines that address specific maladies.
“How do we find new drugs today? Trial and error,” Kaku says. “We have thousands of Petri dishes with chemicals in them. We tediously see whether or not they have any antibiotic properties. Why not do that in the memory of a quantum computer?”
Quantum calculations could also direct the course of gene-editing therapies with the potential of heading off diseases before they arise — an application that raises hopes as well as ethical concerns.
“Any discipline that requires the use of molecules and atoms can be helped by the quantum revolution, including cancer research, aging. Why do we die? Think about it for a moment: There are zero laws of physics that say that we have to die,” Kaku says.
Doesn’t immortality run counter to the Second Law of Thermodynamics? “If I have an open system and I use quantum computers to add extra energy from outside, I can begin the process of stopping the aging process,” Kaku says. “Think about that: the possibility of extending the human lifespan by reducing the buildup of errors in our DNA. … The applications are endless.”
He’s even hoping that next-generation computing will help him solve the mysteries of string theory and reveal the so-called Theory of Everything, which Kaku calls the God Equation. That hope is what led him to write “Quantum Supremacy” in the first place.
Kaku has been working on string theory for decades, and he’s the author of one of the leading textbooks about it. But he says the theory is “so complicated, with so many resonances, that the human mind has not been able to solve string theory.”
“What a frustrating thing,” he says. “So I said to myself, wait a minute. String theory is a quantum theory, like the atom. Why not use quantum computers to solve a quantum problem?”
By now, you’ve probably gotten the message that Kaku is bullish on the quantum revolution. Is he willing to admit there’s something that quantum computers can’t do? Yes, as a matter of fact.
If a movie like “Everything Everywhere All at Once” makes it look as if you can slip back and forth between quantum universes, Kaku says you should know that’s pure fiction. “It doesn’t work that way,” he says. “It turns out that it takes an enormous amount of energy and time to go between universes. So, believe it or not, it may be possible to go between universes, but it’s not for us.”
In other words, not even the quantum computer revolution can change everything everywhere all at once.