Simulating the Universe: From Black Holes to String Theory with Quantum Computers
Book: Quantum Supremacy: How the Quantum Computer Revolution Will Change Everything Author: Dr. Michio Kaku Published: 2023, Doubleday ISBN: 978-0385548366
The Chapter Where Kaku Simulates Everything
Chapter 16 is the most ambitious in the entire book. Kaku says quantum computers will help us understand the universe itself. Not bits of it. The whole thing. From asteroids to black holes to the Theory of Everything that Einstein spent his last thirty years chasing.
This chapter covers so much ground it reads like a physics textbook condensed into forty pages. Kaku keeps it moving with personal stories and practical examples though.
Killer Asteroids and Why We Need Better Math
Kaku starts with something very practical. Sixty-six million years ago, a six-mile-wide rock slammed into the Yucatan Peninsula and wiped out 75 percent of all life on Earth. As Kaku puts it, the dinosaurs did not have a space program, so they are not here to discuss this question. We do though.
About 27,000 near-Earth asteroids have been tracked so far. Tens of millions of smaller ones go unwatched though. Long-period comets from beyond Pluto could show up with maybe a few weeks of warning. NASA’s DART probe in 2021 pushed an asteroid off course for the first time. Detecting and predicting trajectories of millions of objects requires computing power that classical machines cannot deliver though.
He also mentions asteroid Apophis, which will skim Earth’s atmosphere in April 2029, close enough to see with the naked eye. Its trajectory after that pass is hard to predict. A concrete problem where quantum computing matters.
Stars, Solar Flares, and the Carrington Event
One of my favorite sections is about stellar evolution. Kaku tells a story about his roommate in grad school at Berkeley who said every morning that he was going to “bake a star in an oven.” Turns out he meant running simulations of stellar life cycles on a computer. Input a hydrogen gas cloud in the morning, by lunchtime it collapses and ignites, by afternoon it is fusing heavy elements for billions of simulated years.
These simulations have gaps though. The gaps matter because of things like the Carrington Event. In 1859, the biggest solar flare in recorded history hit Earth. Telegraph wires caught fire across Europe and North America. You could read a newspaper at night in the Caribbean just from the aurora borealis. A gold miner in Australia described it as “a scene of almost unspeakable beauty.”
Now imagine that today. Lloyd’s of London estimated another Carrington Event could cause $2.6 trillion in damages. Satellites, internet, power grids, financial systems, all gone. We got a taste in 2022 when a solar burst wiped out 40 of 49 SpaceX Starlink satellites.
The equations for plasma, fusion, convection, and magnetism inside a star are known, but solving them together is beyond classical computers. Quantum computers could model the sun’s interior and give us advance warning.
Black Holes and What Is Inside Them
When a massive star collapses, Einstein’s math says it forms a singularity behind an event horizon. The event horizon of the black hole in galaxy M87 was photographed in 2021 by linking radio telescopes around the planet.
What is inside though? Physicists now think rotating black holes might collapse into a spinning ring of neutrons. The math says if you fall through that ring, you might not die but enter a parallel universe. Kaku compares it to Alice’s looking glass: Oxford on one side, Wonderland on the other.
The catch is that these calculations need Einstein’s gravity and quantum mechanics combined, and the equations become hopelessly tangled. Quantum computers might be the only way to solve them.
Dark Matter: 95 Percent of the Universe Is Missing
An embarrassing fact that Kaku lays out clearly. Most elementary school textbooks say the universe is made of atoms. Wrong. The universe is 68 percent dark energy, 27 percent dark matter, 5 percent hydrogen and helium, and 0.1 percent everything else. We are literally a rounding error.
Dark matter does not interact with regular matter. If you held it in your hand, it would fall through your fingers, through the floor, through the Earth, come out in China, and oscillate back. We detect it only because it bends light. We have 3D maps of it around galaxies. No idea what it actually is though.
The Standard Model: A Mess That Works
Kaku’s description of the Standard Model is brutally honest. Billions of dollars, scores of Nobel Prize winners, and the result is, in his words, a mess. Thirty-six quarks and antiquarks, nineteen adjustable parameters, three generations of identical particles, plus gluons, bosons, and more. He compares it to taping an aardvark, platypus, and whale together and calling it nature’s finest creation.
It works though. Most physicists believe it is just the lowest-energy approximation of something more elegant. In 2021, Fermilab found the first possible crack: a tiny deviation in the magnetic properties of mu mesons. If it holds up, it could signal physics beyond the Standard Model.
String Theory and the Theory of Everything
This is where Kaku gets personal, because he is one of the co-founders of string field theory. He says string theory is the only candidate for a Theory of Everything that satisfies three criteria: it contains Einstein’s gravity, it contains the entire Standard Model, and it is mathematically consistent.
The core idea is elegant. All particles are just different vibrations of tiny strings, like different notes on a rubber band. Physics is the harmony, chemistry is the melody, and the universe is a symphony. When you calculate the vibrations, gravity naturally emerges as one of the lowest notes.
String theory has the “landscape problem” though. It might have an infinite number of solutions, each describing a different possible universe. Which one is ours? Kaku’s answer: put string theory onto a quantum computer. Use quantum computing’s natural ability to survey vast collections of paths simultaneously. Maybe most solutions are unstable and decay, leaving only the correct one. Our universe as the only stable solution.
He draws a parallel to Lattice QCD, where physicists gave up solving equations by hand and now use supercomputers to solve them cube by cube across a lattice of space-time. String theory might need the same approach, but with quantum computers.
My Take
This chapter is Kaku at his most ambitious. He is basically saying quantum computers are the telescope of our era. Just like Galileo’s telescope overturned everything known about the heavens, quantum computers will overturn everything we think we know about physics itself.
As an engineer, I find the practical applications more convincing than the theoretical ones. Tracking asteroids, predicting solar flares, analyzing particle collider data: concrete problems with clear scaling bottlenecks. String theory is a bigger bet. Kaku makes a reasonable case for it though.
The most honest moment is when he admits the Standard Model, the crowning achievement of particle physics, is ugly and awkward. That intellectual honesty is what makes his writing worth reading. He does not pretend we have it figured out. He points at the gaps and says: here is what quantum computers could fill.
This is part of a series reviewing Michio Kaku’s “Quantum Supremacy.” Each post covers one chapter.