by Michio Kaku
Next, the master computer becomes so large and powerful that it has to be placed in hyperspace, and eventually humanity merges with it. Maybe someday we can become like the Star Maker and from our vantage point in hyperspace look down and see our universe, coexisting with other universes in the multiverse, each containing billions of galaxies. Analyzing the landscape of possible universes, we may choose a new universe that is still young, that can provide a new home. We would choose a universe that has stable matter, like atoms, and is young enough that stars can create new solar systems to spawn new forms of life. So the distant future, instead of being a dead end for intelligent life, might see the birth of a new home for it. If this is the case, then the death of the universe is not the end of the story.
Our only chance of long-term survival is not to remain lurking on planet Earth, but to reach out into space…But I am an optimist. If we can avoid disaster for the next two centuries, our species should be safe, as we spread into space. Once we establish independent colonies, our entire future should be safe.
—STEPHEN HAWKING
Every dream begins with a dreamer. Always remember, you have within you the strength, and the passion, to reach for the stars to change the world.
—HARRIET TUBMAN
NOTES
PROLOGUE
One day about seventy-five thousand years ago: A. R. Templeton, “Genetics and Recent Human Evolution,” International Journal of Organic Evolution 61, no. 7 (2007): 1507–19. See also Supervolcano: The Catastrophic Event That Changed the Course of Human History; Could Yellowstone Be Next? (New York: MacMillan, 2015).
Stark evidence of this cataclysm: Although there is universal agreement that the eruption of the supervolcano at Toba was a truly catastrophic event, it should be pointed out that not all scientists believe it altered the direction of human evolution. One group, from Oxford University, analyzed sediments in Lake Malawi in Africa going back tens of thousands of years into the past. By drilling into the lake bottom, one can retrieve sediments that were deposited in the ancient past and hence re-create ancient weather conditions. Analysis of this data from the time of the Toba volcano showed no significant sign of permanent climate change, which casts doubt on the theory. However, it remains to be seen if this result can be generalized to other areas besides Lake Malawi. Another theory is that the bottleneck in human evolution about seventy-five thousand years ago was caused by slow environmental effects rather than a sudden collapse of the environment. Further research is required to definitively settle the question.
CHAPTER 1: PREPARING FOR LIFTOFF
As a youth, he spent most of his time: Newton’s three laws of motion are:
· An object in motion stays in motion, unless acted on by an outside force. (This means that our space probes can reach the distant planets with minimal fuel once they are in space, because they basically coast their way to the planets, since there is no friction in space.)
· Force equals mass times acceleration. This is the fundamental law behind Newtonian mechanics, which makes possible the building of skyscrapers, bridges, and factories. At any university, a first-year course in physics is basically solving this equation for different mechanical systems.
· For every action, there is an equal and opposite reaction. This is the reason why rockets can move in outer space.
These laws work perfectly well when shooting space probes throughout the solar system. However, they inevitably break down in several important domains: (a) extremely fast velocities approaching the speed of light, (b) extremely intense gravitational fields, such as near a black hole, and (c) extremely small distances found inside the atom. To explain these phenomena, we need Einstein’s theory of relativity and also the quantum theory.
“To place one’s feet on the soil of asteroids”: Chris Impey, Beyond (New York: W.W. Norton, 2015).
“That Professor Goddard”: Impey, Beyond, p. 30.
Wernher von Braun would take the sketches, dreams, and models: Historians still debate precisely how much cross-fertilization there was between pioneers like Tsiolkovsky, Goddard, and von Braun. Some claim that each worked in near total isolation and independently rediscovered one another’s work. Others claim that there was considerable interaction between them, especially because much of their work was published. But it is known that the Nazis made inquiries to Goddard, asking for his advice. So it is safe to say that von Braun, because he had access to the German government, was fully aware of the developments of his predecessors.
“I plan on traveling to the Moon”: Hans Fricke, Der Fisch, der aus der Urzweit kam (Munich: Deutscher Taschenbuch-Verlag, 2010), pp. 23–24.
“I reach for the stars, but sometimes I hit London”: See Lance Morrow, “The Moon and the Clones,” Time, August 3, 1998. For more on the political legacy of von Braun, see M. J. Neufeld, Wernher von Braun: Dreamer of Space, Engineer of War (New York: Vintage, 2008). Also, parts of this discussion were based on a radio interview I conducted with Mr. Neufeld in September 2007. Many have written about this great scientist, who opened up the space age but did it using financial backing from the Nazis, and have come to differing conclusions.
While the U.S. rocketry program proceeded by fits and starts: See R. Hal and D. J. Sayler, The Rocket Men: Vostok and Voskhod, the First Soviet Manned Spaceflights (New York: Springer Verlag, 2001).
“Congress came to see NASA primarily as a jobs program”: See Gregory Benford and James Benford, Starship Century (New York: Lucky Bat Books, 2014), p. 3.
CHAPTER 2: NEW GOLDEN AGE OF SPACE TRAVEL
“The whole idea is to preserve the Earth”: Peter Whoriskey, “For Jeff Bezos, The Post Represents a New Frontier,” Washington Post, August 12, 2013.
In the 1990s, an unexpected discovery caught scientists by surprise: See R. A. Kerr, “How Wet the Moon? Just Damp Enough to Be Interesting,” Science Magazine 330 (2010): 434.
The Chinese have announced that they will put their astronauts on the moon: See B. Harvey, China’s Space Program: From Conception to Manned Spaceflight (Dordrecht: Springer-Verlag, 2004).
One factor that limits how long our astronauts can stay on the moon: See J. Weppler, V. Sabathier, and A. Bander, “Costs of an International Lunar Base” (Washington, D.C.: Center for Strategic and International Studies, 2009); https://csis.org/publication/costs-international-lunar-base.
CHAPTER 3: MINING THE HEAVENS
Planetary Resources estimates that the platinum: See www.planetaryresources.com.
CHAPTER 4: MARS OR BUST
“Failure is an option here [at SpaceX]”: For more quotes from Elon Musk, see www.investopedia.com/university/elon-musk-biography/elon-musk-most-influential-quotes.asp.
“They say Mars is the new black”: See https://manofmetropolis.com/nick-graham-fall-2017-review.
“I really don’t have any other motivation”: The Guardian, September 2016; www.theguardian.com/technology/2016/sep/27/elon-musk-spacex-mars-exploration-space-science.
“I’m convinced”: The Verge, October 5, 2016; www.theverge.com/2016/10/5/13178056/boeing-ceo-mars-colony-rocket-space-elon-musk.
“I think it’s good for there to be multiple paths to Mars”: Business Insider, October 6, 2016; www.businessinsider.com/boeing-spacex-mars-elon-musk-2016-10.
“NASA applauds all those”: Ibid.
Bill Gerstenmaier, of NASA’s Human Exploration and Operations Directorate: See www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations.
CHAPTER 5: MARS: THE GARDEN PLANET
“Actually, it was Sputnik”: Interview on Science Fantastic radio, June 2017.
Another outlandish attempt to form an isolated colony: See R. Reider, Dreaming the Biosphere (Albuquerque: University of New Mexico Press, 2010).
CHAPTER 6: GAS GIANTS, COMETS, AND BEYOND
Using Newton’s laws, astronomers can calculate: The calculation of the Roche limit and tidal forces requires only an elementary application of Newton’s law of gravity. Because a mo
on is a spherical object and not a point particle, the force of attraction from a gas giant like Jupiter is larger on the side facing Jupiter than the gravity on the far side. This causes the moon to bulge a bit. But one can also calculate the force of gravity, which holds the moon together via its own gravitational pull. If the moon gets close enough, the force of gravity that is pulling the moon apart balances the force of gravity that holds the moon together. At that point, the moon begins to disintegrate. This gives us the Roche limit. All the rings of the gas giants that have been documented lie within the Roche limit. This indicates, but does not prove, that the rings of the gas giants were caused by tidal forces.
Beyond the gas giants, at the outer reaches of our solar system: Comets from the Kuiper Belt and Oort Cloud probably have different origins. Originally, the sun was a gigantic ball of hydrogen gas and dust, perhaps a few light-years across. As the gas began to collapse because of gravity, it began to spin faster. At that point, some of the gas collapsed into a spinning disk, which eventually condensed into the solar system. Since this spinning disk contained water, this created a ring of comets in the outer reaches of the solar system. This became the Kuiper Belt. However, some of the gas and dust did not condense into this spinning disk. Some of it condensed into chunks of stationary ice, roughly tracing out the original outlines of the original protostar. This became the Oort Cloud.
CHAPTER 7: ROBOTS IN SPACE
“AlphaGo can’t even play chess”: Discover Magazine, April 2017; discovermagazine.com/2017/april-2017/cultivating-common-sense.
In 2017, a controversy arose between two billionaires: Many fear that AI could revolutionize the job market, putting millions of people out of work. This may very well happen, but there are other trends that might reverse this effect. New jobs will open up—in designing, repairing, maintaining, and servicing robots—as the industry explodes in size, perhaps rivaling the automobile industry. Furthermore, there are many classes of jobs that cannot be replaced by robots for decades to come. For example, semiskilled, nonrepetitive workers—such as janitors, police, construction workers, plumbers, gardeners, contractors, et cetera—cannot be replaced by robots. Robots, for example, are too primitive to pick up garbage. In general, jobs that will be difficult to automate with robots include jobs involving (a) common sense, (b) pattern recognition, and (c) human interactions. For example, in a law firm, the paralegal might be replaced, but lawyers are still needed to argue cases before a live jury or judge. Middlemen, especially, may find themselves out of work, so they will have to add value to their services (i.e., intellectual capital). This means adding analysis, experience, intuition, and innovation, which robots are deficient in.
“We are ourselves creating our own successors”: Samuel Butler, Darwin Among the Machines; www.historyofinformation.com/expanded.php?id=3849.
“I visualize a time when we will be to robots what dogs are to humans”: For more quotes from Claude Shannon, see www.quotes-inspirational.com/quote/visualize-time-robots-dogs-humans-121.
“It is ridiculous to talk about such things so early”: Raffi Khatchadourian, “The Doomsday Invention,” New Yorker, November 23, 2015; www.newyorker.com/magazine/2015/11/23/doomsday-invention-artificial-intelligence-nick-bostrom.
When addressing the Zuckerberg/Musk controversy: The debate about the dangers and benefits of AI has to be put into perspective. Every discovery can be used for good or evil. When the bow and arrow was first invented, it was mainly used to hunt small game, like squirrels and rabbits. But eventually, it evolved into a formidable weapon that could be used to hunt other humans. Similarly, when the first airplanes were invented, they were used for recreation and delivering the mail. But eventually, they evolved into weapons that can deliver bombs. Similarly, AI for many decades to come will be a useful invention that can generate jobs, new industries, and prosperity. But eventually, these machines can pose an existential risk if they become too intelligent. At what point will they become dangerous? I personally believe that tipping point will occur when they become self-aware. Currently, robots do not know they are robots, but that could change radically in the future. However, this tipping, in my opinion, probably won’t be reached until near the end of this century, giving us time to prepare.
He believes that by 2045, we will reach the “singularity”: One should be careful when analyzing one aspect of the singularity: that future generations of robots can be smarter than the previous generation so that one can rapidly create superintelligent robots. One can, of course, create computers that have increasingly large amounts of memory, but does this mean that they are “smarter”? In fact, no one has been able to demonstrate even a single computer that can create a second-generation computer that is more intelligent. There is, in fact, no rigorous definition of the word smart. This does not mean that it is impossible for this to happen, it only means that the process is ill defined. In fact, it is not clear how this will be accomplished.
In order to create self-aware machines: The key to human intelligence, in my opinion, is our ability to simulate the future. Humans constantly plan, scheme, daydream, ponder, and muse about the future. We can’t help it. We are prediction machines. But one of the keys to simulating the future is understanding the laws of common sense, of which there are billions. These laws, in turn, depend on understanding the basic biology, chemistry, and physics of the world around us. The more accurate our understanding of these laws, the more accurate our simulation of the future will be. At present, the common sense problem is one of the major hurdles in AI. Massive attempts to codify all the laws of common sense have all failed. Even a child has more common sense than our most advanced computer. So in other words, a robot that tries to take over the world from humans will fail miserably because it doesn’t understand the simplest things about our world. It is not enough for a robot to try to dominate humans; one has to master the simplest laws of common sense in order to carry out a plan. For example, giving a robot the simple goal of robbing a bank will ultimately result in failure because the robot cannot realistically map out all possible future scenarios.
CHAPTER 8: BUILDING A STARSHIP
In a subsequent phase of the project: R. L. Forward, “Roundtrip Interstellar Travel Using Laser-Pushed Lightsails,” Journal of Spacecraft 21, no. 2 (1984): 187–95.
Laser-propelled nanoships: See G. Vulpetti, L. Johnson, and L. Matloff, Solar Sails: A Novel Approach to Interplanetary Flight (New York: Springer, 2008).
“There will some day appear velocities far greater than these”: Jules Verne, From the Earth to the Moon. Quoted at www.space.com/5581-nasa-deploy-solar-sail-summer.html.
The idea was developed by nuclear physicist Ted Taylor: G. Dyson, Project Orion: The True Story of the Atomic Spaceship (New York: Henry Holt, 2002).
There are several ways in which to release the power of fusion peacefully: S. Lee and S. H. Saw, “Nuclear Fusion Energy—Mankind’s Giant Step Forward,” Journal of Fusion Energy 29, 2, 2010.
The nuclear fusion rocket is conceptually sound: The fundamental reason why magnetic fusion has not yet been attained on the Earth is because of the stability problem. In nature, giant balls of gas can be compressed so that the star ignites, because gravity compresses the gas uniformly. However, magnetism involves two poles, north and south. Therefore, it is impossible to compress gas uniformly using magnetism. When you squeeze gas magnetically in one area, it bulges out the other end. (Think of trying to squeeze a balloon. If you pinch the balloon in one place, it expands in another.) One idea is to create a doughnut-shaped magnetic field and have the gas compressed on the inside of the doughnut. But physicists have failed to compress hot gas for more than a tenth of a second, which is too brief to create a self-sustaining fusion reaction.
They would utilize the greatest energy source in the universe: Although antimatter rockets convert matter into energy with 100 percent efficiency, there are also some hidden losses. For example, some of the energy of a matter/antimatter collision is in the form of neutrino
s, which cannot be harvested to create usable energy. Our bodies are continually radiated by neutrinos from the sun, yet we feel nothing. Even when the sun sets, our bodies are irradiated by neutrinos that have gone right through the planet Earth. In fact, if you could somehow shine a beam of neutrinos through solid lead, it might penetrate a light-year of lead before it is finally stopped. So the neutrino energy created by matter/antimatter collisions is lost and cannot be used to generate power.
The ramjet fusion rocket is another enticing concept: R. W. Bussard, “Galactic Matter and Interstellar Flight,” Astronautics Acta 6 (1960): 179–94.
Space elevators would be a game-changing application: D. B. Smitherman Jr., “Space Elevators: An Advanced Earth-Space Infrastructure for the New Millennium,” NASA pub. CP 2000-210429.
“Probably about fifty years after everyone stops laughing”: NASA Science, “Audacious and Outrageous: Space Elevators”; https://science.nasa.gov/science-news/science-at-nasa/2000/ast07sep_1.
One day, a boy read a children’s book and changed world history: Einstein’s theory of special relativity is based on the simple sentence: “The speed of light is constant in any inertial frame [i.e. in any uniformly moving frame].” This violates Newton’s laws, which say nothing about the speed of light. In order for this law to be satisfied, there have to be vast changes in our understanding of the laws of motion. From that one statement, one can show that:
· The faster you move in a rocket ship, the slower time beats inside that rocket.
· Space is compressed within that rocket the faster you move.
· You get heavier the faster you move.
As a result, this means that at the speed of light, time would stop and you would become infinitely flat and infinitely heavy, which is impossible. Hence, you cannot break the light barrier. (In the Big Bang, however, the universe expanded so rapidly that the expansion exceeded the speed of light. This is not a problem, because it’s empty space that is stretching faster than light. Material objects, however, are forbidden to go faster than light.)