Physics of the Future

Michio Kaku, a professor of theoretical physics at the City University of New York, draws on interviews with more than 300 scientists to construct a science-based forecast of how technology will reshape human civilization by the year 2100. The book's central argument is that prototypes of every transformative technology already exist in laboratories, and that the known laws of physics allow these innovations to be traced across three time horizons: the near future (present to 2030), midcentury (2030 to 2070), and the far future (2070 to 2100).

Kaku opens with two childhood experiences that shaped his career: learning about Einstein's unfinished "theory of everything" and watching the Flash Gordon television series, which taught him that scientists, not action heroes, create the future. He recounts building a 2.3-million-electron-volt particle accelerator in his mother's garage as a teenager, positioning himself as an insider rather than an outsider making predictions. He argues that previous forecasts by historians and futurists consistently underestimated the pace of progress, while this book rests on firmer ground because the four fundamental forces of nature (gravity, electromagnetism, and the weak and strong nuclear forces) are now largely understood. He introduces the "Cave Man Principle": Whenever modern technology conflicts with desires shaped by 100,000 years of evolution, primitive desires win. This explains why the paperless office and cybertourism never materialized, and why gossip and entertainment dominate the Internet rather than the educational uses originally envisioned.

The first major subject is the future of computers. Kaku traces "ubiquitous computing" to Mark Weiser of Xerox PARC, who predicted in the early 1990s that chips would become so cheap they would be embedded in clothing, furniture, and bodies. Moore's law, the observation that computer power doubles roughly every 18 months, has driven this transformation. In the near future, Kaku forecasts Internet contact lenses, driverless cars, and wall screens made of flexible organic light-emitting diodes. By midcentury, Moore's law will begin to falter as transistors approach the atomic scale. Augmented reality will blend physical and virtual worlds, and prototype universal translators will provide real-time translation. By 2100, brain-computer interfaces, building on Brown University's BrainGate chip that already enables paralyzed patients to control cursors with their thoughts, could evolve into telekinesis: A person would think a command, a computer would interpret it, and magnetic fields from room-temperature superconductors embedded in objects would move them.

Kaku then turns to artificial intelligence. He recounts interacting with Honda's ASIMO robot for television and discovering that every lifelike gesture was carefully scripted; an inventor privately admitted the robot has the intelligence of an insect. Two unsolved problems prevent robot maids: pattern recognition (robots cannot understand what they see) and common sense. In the near future, expert systems will provide medical and legal advice on wall screens. By midcentury, modular robots will change shape, robotic surgeons will manipulate microscopic tissue, and reverse-engineering the brain will advance through projects like IBM's Blue Gene neural simulations and optogenetics, a technique combining optics and genetics to trace neural pathways. Kaku addresses the singularity, the hypothetical point when machines surpass human intelligence, as popularized by inventor Ray Kurzweil, who predicts this will occur by 2045. Kaku argues the singularity is unlikely before 2100 because Moore's law will slow and raw computing speed does not equal intelligence. He advocates "friendly AI," robots designed from the start to help humans, combined with gradual human-robot merging through cochlear implants and artificial retinas.

Medicine occupies a substantial portion of the book. The cost of sequencing a human genome is plunging from three billion dollars toward one thousand, opening the door to personalized treatment. Kaku forecasts bathroom sensors detecting cancer colonies of a few hundred cells, tissue engineering that grows replacement organs, and gene therapy for single-gene diseases. Cancer, however, will resist a single cure because it is a collection of genetic diseases: The Cancer Genome Project found 23,000 mutations in a single lung cancer cell. By midcentury, genetic enhancement of children may become possible, though side effects loom. In the far future, Kaku presents aging as the accumulation of genetic errors driven by the second law of thermodynamics, which dictates that entropy, or disorder, always increases. Researchers have identified the SIR2 gene pathway and the chemical resveratrol, which mimics the benefits of caloric restriction. Kaku predicts that by 2050 a combination of therapies could extend life to 150 years, and by 2100, reversing aging may be possible. He also discusses resurrecting extinct species, noting that the entire Neanderthal genome was sequenced in 2009.

Nanotechnology, the manipulation of individual atoms, could launch a second industrial revolution. Kaku explains why physics changes at the nanoscale, where quantum effects like the Heisenberg uncertainty principle (which states that one cannot know both the position and velocity of a particle) govern molecular bonds. Current applications include nanoparticles that deliver cancer drugs directly to tumor cells. By midcentury, programmable matter made of tiny chips called "catoms" could enable shape-shifting objects. By 2100, the ultimate goal is a replicator: Trillions of nanobots would disassemble raw materials and reassemble them into anything desired. Kaku acknowledges this will be exceedingly difficult to build but violates no law of physics, and notes that eliminating scarcity would upend all existing economic systems.

Space travel faces a fundamental economic barrier: roughly $10,000 per pound to reach orbit. NASA's Kepler satellite is identifying earthlike planets, and Europa, Jupiter's moon with a liquid ocean beneath its ice, is a prime target for finding extraterrestrial life. Kaku surveys propulsion concepts from solar sails and antimatter rockets to the space elevator, a cable of carbon nanotubes stretching into orbit. He also describes working with Cornell physicist Mason Peck on equations for molecular-sized starship probes that could theoretically be accelerated to near light speed.

Kaku analyzes the future of wealth, arguing that the historic shift from commodity capitalism, where wealth derives from physical goods, to intellectual capitalism, where human creativity is the scarce resource, will determine which nations thrive. He frames economic history through four waves of technology, from steam power through high tech, each generating a speculative bubble and crash. Workers performing repetitive tasks will be displaced by robots, while those requiring pattern recognition, common sense, and creativity will flourish. He recounts a conversation with physicist Freeman Dyson at Princeton's Institute for Advanced Study, where Dyson warned that Britain's brightest minds abandoned the hard sciences for banking before World War II, a pattern Dyson saw repeating at Princeton.

The book's final analytical chapter argues all these revolutions converge toward a planetary civilization. On the Kardashev scale, which ranks civilizations by energy consumption, humanity currently rates as Type 0. Kaku estimates Earth will attain Type I status, harnessing all the sunlight falling on the planet, within approximately 100 years. He warns this transition is the most dangerous in history because humanity retains its evolutionary savagery now combined with weapons of mass destruction, and argues that wisdom, democratic debate, and education are the keys to navigating it successfully.

The book concludes with a speculative day in the year 2100. An engineer wakes to a software assistant, controls his home telepathically, and drives a magnetic car on superconducting pavement. His robotic doctor reports that pancreatic cancer cells detected that morning will be destroyed by nanoparticles. He dates a 61-year-old Web designer who looks 25 thanks to genetic age-reversal. The narrative ends with the couple riding the space elevator 100 miles above Earth, witnessing the birth of a planetary civilization.