- The book introduces the basic concepts and history of quantum computing, as well as the current state and future prospects of the technology.
- The book describes the various types and architectures of quantum computers, and the potential applications and implications of quantum computing in various fields and domains.
- The book defines the concept of quantum supremacy, and reviews the recent achievements and milestones in quantum computing, as well as the future possibilities and challenges of quantum computing.
Quantum Supremacy (2023) makes understanding the facts and theory behind quantum computers accessible and easy to understand for everyone. It traces the history of the modern computer and posits a future in which quantum computing takes on the challenges of humanity that are unsolvable with even the most powerful of modern supercomputers.
Table of Contents
Introduction: Understand quantum computers and what they have to do with your future
If you’ve ever read a comic book or watched The Big Bang Theory, you’ve probably heard a little quantum terminology such as parallel universe and Schrödinger’s cat. But many people think that quantum physics is beyond their realm of understanding and consequently not worth the effort to learn about.
If you’re one of those people, get ready to change your mind. Not only is it possible and easy to understand the practical implications of quantum physics in our world, but it’s also important. The quantum realm isn’t just a subject for comic books. In fact, it’s being explored right now.
The future of computing – and therefore the world – is quantum. Given the possibilities for humanity in terms of fuel, medicine, and economics, advancements in quantum computing are something everyone should be paying attention to.
In this summary, we’ll take a look at the state of quantum computers as they exist today – including their power and their limitations. We’ll also take a quick trip through the history of computing that led us to this point. And finally, we’ll talk about the potential impact of quantum computers on society, medicine, and the world at large.
Goodbye silicon
In 2019, Google created a quantum computer called Sycamore. It could solve, in just 200 seconds, a complex mathematical problem that would take our current fastest supercomputer 10,000 years to solve. In digital computing, the basic unit of information is a bit whereas in quantum computing, it’s a qubit. Sycamore runs on 53 qubits and, at that time, that made it the most powerful computer in the world.
But just two years later, the Quantum Innovation Institute in China claimed that their quantum computer was 100 trillion times faster than supercomputers. It ran on 113 qubits.
On November 16 of that same year, the IBM Eagle was revealed which beat them both with 127 qubits. A year later IBM launched Osprey at 433 qubits.
When a quantum computer can outperform a digital computer at a specific task, it’s known as quantum supremacy. Clearly, this point has already been reached. What’s more, we’ve only just scratched the surface of what’s possible.
There are several different ways in which quantum computing functions. Most inventors are using entangled atoms – more on that shortly – but a few researchers have found a way to send information on light beams using a clunky mirror-based setup. The race is on to be the first to optimize this technology. But we’re still many years away from a functioning quantum computer that can solve real-world problems in fields ranging from medicine to fuel to cybersecurity.
Even so, the age of silicon appears to be coming to an end. Moore’s Law, first postulated in 1965, suggests that the number of transistors that can be built into a microchip doubles every 18 months. Effectively, that means computer power also doubles every 18 months. But if we continue primarily using silicon, this law will stop being true in the very near future.
You see, digital computers are reaching their capacity to be able to solve large-scale problems – or at least to be able to solve them quickly enough to be useful. But quantum computers can take us into a new era with their insanely fast speeds and ability to simultaneously analyze multiple paths and problems to create the best solution.
So what is it that makes quantum computers so powerful? Well, two key factors contribute to this power.
The first is superposition, or the ability of an atom to exist in multiple states at the same time. This is how quantum computers can solve problems so quickly – by analyzing all paths at the same time to determine the path of least action.
The second factor is known as entanglement. This is when two atoms establish interaction with each other, sharing information, and keep that connection even when they’re separated at a great distance.
Now, you’re probably already wondering, How do I get my hands on one of these quantum computers? Why isn’t all technology already based on quantum computing? Well, the problem is that there’s one primary challenge, and it has to do with something called coherence.
For quantum computers to work, a system has to be completely stable. Atoms are fragile and the least disturbance disrupts them. So quantum computers as they currently exist have to be framed in systems that keep them at absolute zero temperatures.
There’s hope, though. Mother nature achieves coherence at regular temperatures in a little process called photosynthesis. So scientists are studying how coherence is achieved in nature in the hope of finding a way to recreate the process in a computer.
But before we talk about the practical applications of quantum computers, let’s take a quick look back at how we got here.
Two thousand years of computers
In 1901, off the coast of a Greek island called Antikythera, researchers discovered the remains of a first-century trading ship. On that ship, they found Roman artifacts that they speculate were being sent as a gift to Julius Caesar.
Among those artifacts was a strange hunk of bronze. It was clearly man-made but impossible to identify at the moment of its discovery. In fact, this piece of metal kept researchers confused for decades. In the 1970s, X-ray imaging was used to investigate the artifact, but it wasn’t until CT scans were published in 2006 that researchers started to recognize the implications of the device.
What’s now known as the Antikythera Mechanism provided a highly complex simulation of the universe as it was known at the time. The device could make predictions about events like eclipses, and it could even calibrate in anticipation of changes in speed due to the elliptical orbit of the Earth.
Simulation is the goal of quantum computing. When we can simulate the world around us down to the quantum level, we can begin to analyze some of the many problems that have plagued us since the beginning of time.
No device came close to the technical advancement of the Antikythera device – let alone built on it – until the 1800s. It was then that Charles Babbage invented the first digital computer. Ada Lovelace, daughter of Lord Byron, figured out how to feed the computer information to get it to perform complicated mathematical tasks that were essential in industries such as construction or navigation. She was essentially the first programmer.
By 1900, things were gathering pace, Max Planck challenged Newtonian physics and created what’s now called Planck’s Constant, representing the size of quantum energy. This constant would become the foundation of quantum mechanics and quantum theory.
Then, in 1926, Erwin Schrödinger built on this by creating a wave equation using Planck’s Constant. Rather than seeing electrons as particles, Schrödinger suggested they exist as a wave. In other words, an electron exists in many places at once until the moment it’s measured – which is when the wave would collapse into a particle.
To illustrate this idea, the analogy of Schrödinger’s cat was created. While the cat is in the box, the cat can be considered to be both dead, alive, and all states in between – until it’s observed. At that point, all the states of the cat collapse into the measurable one.
Ten years later, in 1936, Alan Turning described what would eventually become the Turing machine – the basis for all modern computing. His machine helped break the previously uncrackable codes used by the Nazis during WWII. As a result, the war was shortened by two years and an estimated 14 million lives were saved.
In 1948, Richard Feynman finalized his path integral formulation. Prior to that, scientists had observed in photosynthesis that quantum particles tend to follow the path of least action. But how did the particles “know” what that path was? Feynman answered that question. He postulated that because electrons exist in waves, they’re able to experience all paths at once.
This idea led Feynman to create his path integral formulation. Isaac Newton had invented calculus to solve problems that involved motion. The path integral formulation solved those same problems in a much simpler way and it paved the way for yet more quantum discoveries.
If the description of the path integral formulation sounds familiar, that’s probably because we’ve already talked about how quantum computers can experience and analyze all possibilities simultaneously before choosing the best solution. Everything these scientists and inventors of the past created has led to the development of what we know as quantum science today.
One more name needs to be added to this esteemed list, that of Hugh Everett. For a long time, scientists argued about the wave theory and the idea that a wave collapsed into a single reality when measured. This was a huge problem to overcome until Everett proposed that maybe the wave doesn’t actually collapse; maybe all versions of the reality experienced by the wave exist simultaneously.
So, if you enjoy the multiverse of comic books or any other fiction that explores parallel dimensions, Everett is the man to thank.
OK, so while the many worlds theory does make for good entertainment, it’s serious subject matter for quantum physicists and continues to be explored today. So let’s get back to understanding what the value of all of these quantum developments might be in the near future.
Good and evil in progress
In 1918, Fritz Haber won the Nobel Prize in Chemistry for inventing a process which used intense heat and pressure to convert nitrogen into nitrate fertilizer. As a result, a green revolution started, which produced enough food to grow the human species into the 8 billion population size that it is today.
But Fritz Haber is also known by another name: the father of chemical warfare. His inventions were responsible for millions of deaths throughout World War I, the Russian Revolution, and the Holocaust.
Today, that crude and resource-eating process of nitrogen-fixing first invented by Haber is being challenged by quantum scientists.
Thanks to two breakthroughs, we now better understand the building blocks of life.
In 1952, Stanley Miller created an experiment that used many of the elements thought to have existed on prehistoric earth, along with a jolt of electricity, and was able to spontaneously produce amino acids. We now know, through simulations using the elements found in gas clouds in space, that it’s likely that amino acids exist in space and may have been brought here in meteorite dust.
The second breakthrough was that of Francis Crick and James Watson. In his 1944 book entitled What is Life? Schrödinger described the characteristics of an unknown molecule that would explain the development of life as we know it. Crick and Watson took his idea further and identified the double-helix shape of what we now know to be DNA.
Thanks to all of these inventions and discoveries, we understand the pieces and processes needed to produce the energy that sustains life. But there are still many obstacles to overcome. Just like Haber’s crude process for nitrogen-fixing, many of our attempts at coming up with clean energy are actually sourced through unsustainable means, and our efforts at discovery are still done largely by trial and error.
Quantum computers have the potential to be able to solve problems like nitrogen-fixing and harnessing the power of sunlight. Hopefully, it won’t be long before quantum computing can deliver a second green revolution.
When cancer loses
On December 23, 1971, President Richard Nixon signed into effect the National Cancer Act, declaring war on cancer – cancer won. The problem with cancer is that it comes from far too many different variables to easily identify and stop it.
Cancer isn’t a foreign invader; it’s created by our own healthy cells. Once we reach adulthood, some cells are programmed to die as others divide. In the case of cancer, healthy cells forget to die off and instead reproduce at an alarming rate.
There are many diseases caused by our bodies harming themselves as opposed to foreign invaders. Take COVID-19, for instance. The deaths associated with COVID-19 weren’t as a result of the symptoms of the virus, but rather the cytokine storm created by the immune system going off the rails.
Another example of the body turning against itself is in autoimmune diseases which happen when the body receives misinformation about an otherwise healthy particle and begins to attack itself.
Alzheimer’s and other neurological disorders may be a result of something called prions, which are improperly folded proteins. No one knows why a protein misfolds, but when it does, it can send that information to other proteins, spreading the disorder.
Technological advancements have improved our quality and length of life. From sanitation to antibiotics and vaccines to better nutrition, we’ve taken the human race from lifespans of approximately 30 years to 70 years and improved the overall quality of those lifespans, too. But we’ve done all of this largely by trial and error. When it comes to things like cancer and Alzheimer’s where there are so many factors at play we may never be able to find answers on our own, quantum computers may save us.
Our planet and beyond
Let’s now switch our focus to climate change and space.
Earth is warming up as a result of human behavior. This warming is creating a variety of problems. One of those is the release of the greenhouse gas methane due to the melting of polar ice caps. As it’s released, it contributes to yet more global warming.
Another consequence of climate change is that the polar vortex, which has always been quite stable, is becoming unstable. This area of cold air and low pressure at the poles is always there but is stronger in winter. In recent decades, it’s been expanding, pushing colder, more unpredictable weather further south.
The consequences of climate change range from mildly inconvenient to catastrophic, and the fact is that we can no longer prevent disaster, we can only mitigate it.
Unfortunately, we’re also reaching a limit on what digital computers can do as far as predicting weather patterns and assessing climate change. Quantum computers, on the other hand, can theoretically provide virtual weather reports that could alter the future of humanity. Their ability to simultaneously assess many paths means they can more quickly generate accurate predictions about short- and long-term weather situations.
Beyond our climate, there’s another important application of quantum computers, and that’s the ability to understand the stars.
Back in 1859, the biggest solar flare in recorded history hit Earth. It resulted in intensely beautiful Northern Lights – but it also resulted in telegraph wires setting alight.
Today, if that same storm were to hit, it would potentially set us back 150 years, not only disrupting our satellite and radio communications but also completely destroying power grids.
The big problem is that we don’t understand how stars work or what causes different intensities in solar storms, so we have no means of predicting and preparing for them. With their ability to simulate the universe, quantum computers could help us better understand our sun and not be caught off guard by unexpected solar flares.
These computers can also help us bottle the power of the sun. The current state of fusion reactors is moving forward. In December 2022, a fusion reaction greater than the amount of energy it took to create that reaction was achieved.
But we’re still at least several decades away from commercializing fusion and powering our world with it. The problem is that we have to figure all of this out by trial and error. And the expense involved in failing is prohibitive. Quantum computers can help us more quickly find our best path forward, simulating all possibilities and showing us the right one.
When we can better understand our planet and our universe, we can not only improve the life and longevity of our planet, we can truly become an interplanetary species.
Summary
Quantum computers exist and are rapidly improving. Not only are there functioning computers cracking codes and performing complex equations at unheard-of speeds, but there are also different forms of them. Quantum computers are the natural progression in a short, rapid series of discoveries and inventions by people like Erwin Schrodinger, Richard Feynman, and Hugh Everett. The possibilities for things like a second green revolution and a cure for cancer all hinge on our ability to take quantum computers to the next level.
MICHIO KAKU is a professor of physics at the City University of New York, cofounder of string field theory, and the author of several widely acclaimed science books, including Hyperspace, Beyond Einstein, Physics of the Impossible, and Physics of the Future. He is the science correspondent for CBS’s This Morning and host of the radio programs Science Fantastic and Explorations in Science.
Genres
Science, Technology and the Future, History, Society, Culture, Nonfiction, Physics, Business, Computers, Engineering, Computer Science, Quantum Physics, Theories of Science, Quantum Theory, Social Aspects of Technology, Artificial Intelligence and Semantics
Table of Contents
ACKNOWLEDGEMENTS
INTRODUCTION Predicting the Next 100 years
FUTURE OF THE COMPUTER Mind over Matter
FUTURE OF AI Rise of the Machines
FUTURE OF MEDICINE Perfection and Beyond
NANOTECHNOLOGY Everything from Nothing?
FUTURE OF ENERGY Energy from the Stars
FUTURE OF SPACE TRAVEL To the Stars
FUTURE OF WEALTH Winners and Losers
FUTURE OF HUMANITY Planetary Civilization
A DAY IN THE LIFE IN 2100
NOTES
RECOMMENDED READING
INDEX
Review
The book is an introduction to the field of quantum computing, which uses the principles of quantum mechanics to perform calculations that are impossible or impractical for classical computers. The author, Dr. Michio Kaku, is a renowned theoretical physicist and a popularizer of science. He explains the basic concepts and history of quantum computing, as well as the current state and future prospects of the technology.
The book is divided into four parts:
- Part I: The Quantum Revolution. This part covers the origins and development of quantum theory, from the early discoveries of Planck, Einstein, Bohr, and Heisenberg, to the modern interpretations of Schrödinger, Feynman, and Everett. It also introduces the key concepts of quantum computing, such as qubits, superposition, entanglement, interference, and decoherence.
- Part II: Quantum Computers. This part describes the various types and architectures of quantum computers, such as superconducting, trapped ion, photonics, topological, and quantum annealing. It also discusses the challenges and limitations of building and operating quantum computers, such as scalability, error correction, and noise.
- Part III: Quantum Applications. This part explores the potential applications and implications of quantum computing in various fields and domains, such as cryptography, artificial intelligence, medicine, chemistry, physics, astronomy, and cosmology. It also examines the ethical and social issues that may arise from the use of quantum computing, such as privacy, security, and governance.
- Part IV: Quantum Supremacy. This part defines the concept of quantum supremacy, which is the point when a quantum computer can perform a task that is beyond the reach of any classical computer. It also reviews the recent achievements and milestones in quantum computing, such as Google’s Sycamore processor and IBM’s Quantum Experience platform. It also speculates on the future possibilities and challenges of quantum computing, such as quantum internet, quantum artificial intelligence, quantum consciousness, and quantum gravity.
I found the book to be very informative, engaging, and accessible for anyone who is interested in learning about quantum computing. The author writes with clarity, enthusiasm, and humor, using analogies, examples, and anecdotes to illustrate complex ideas and concepts. He also provides references and suggestions for further reading for those who want to delve deeper into the topic.
The book is not only about quantum computing as a technology, but also about quantum computing as a paradigm shift that may transform our understanding of reality and our role in the universe. It shows how quantum computing may enable us to solve some of humanity’s biggest problems, such as global warming, world hunger, and incurable diseases. It also shows how quantum computing may reveal some of nature’s deepest secrets, such as the origin of life, the nature of time, and the fate of the cosmos.
The book is not only for scientists or technologists who work on or with quantum computing but also for anyone who is curious about one of the most fascinating and important developments in science and technology today. It is for anyone who wants to learn how to think like a quantum physicist: understanding the power and potential of quantum computing.