Dreams of Earth and Sky

by Freeman Dyson

  On December 8, 2010, Gleick published on the The New York Review’s blog an illuminating essay, “The Information Palace.” It was written too late to be included in his book. It describes the historical changes of meaning of the word “information,” as recorded in the latest quarterly online revision of the Oxford English Dictionary. The word first appears in 1386 in a parliamentary report with the meaning “denunciation.” The history ends with the modern usage, “information fatigue,” defined as “apathy, indifference or mental exhaustion arising from exposure to too much information.”

  The consequences of the information flood are not all bad. One of the creative enterprises made possible by the flood is Wikipedia, started ten years ago by Jimmy Wales. Among my friends and acquaintances, everybody distrusts Wikipedia and everybody uses it. Distrust and productive use are not incompatible. Wikipedia is the ultimate open-source repository of information. Everyone is free to read it and everyone is free to write it. It contains articles in 262 languages written by several million authors. The information that it contains is totally unreliable and surprisingly accurate. It is often unreliable because many of the authors are ignorant or careless. It is often accurate because the articles are edited and corrected by readers who are better informed than the authors.

  Wales hoped when he started Wikipedia that the combination of enthusiastic volunteer writers with open-source information technology would cause a revolution in human access to knowledge. The rate of growth of Wikipedia exceeded his wildest dreams. Within ten years it has become the biggest storehouse of information on the planet and the noisiest battleground of conflicting opinions. It illustrates Shannon’s law of reliable communication. Shannon’s law says that accurate transmission of information is possible in a communication system with a high level of noise. Even in the noisiest system, errors can be reliably corrected and accurate information transmitted, provided that the transmission is sufficiently redundant. That is, in a nutshell, how Wikipedia works.

  The information flood has also brought enormous benefits to science. The public has a distorted view of science because children are taught in school that science is a collection of firmly established truths. In fact, science is not a collection of truths. It is a continuing exploration of mysteries. Wherever we go exploring in the world around us, we find mysteries. Our planet is covered by continents and oceans whose origin we cannot explain. Our atmosphere is constantly stirred by poorly understood disturbances that we call weather and climate. The visible matter in the universe is outweighed by a much larger quantity of dark invisible matter that we do not understand at all. The origin of life is a total mystery, and so is the existence of human consciousness. We have no clear idea how the electrical discharges occurring in nerve cells in our brains are connected with our feelings and desires and actions.

  Even physics, the most exact and most firmly established branch of science, is still full of mysteries. We do not know how much of Shannon’s theory of information will remain valid when quantum devices replace classical electric circuits as the carriers of information. Quantum devices may be made of single atoms or microscopic magnetic circuits. All that we know for sure is that they can theoretically do certain jobs that are beyond the reach of classical devices. Quantum computing is still an unexplored mystery on the frontier of information theory. Science is the sum total of a great multitude of mysteries. It is an unending argument between a great multitude of voices. Science resembles Wikipedia much more than it resembles the Encyclopaedia Britannica.

  The rapid growth of the flood of information in the last ten years made Wikipedia possible, and the same flood made twenty-first-century science possible. Twenty-first-century science is dominated by huge stores of information that we call databases. The information flood has made it easy and cheap to build databases. One example of a twenty-first-century database is the collection of genome sequences of living creatures belonging to various species from microbes to humans. Each genome contains the complete genetic information that shaped the creature to which it belongs. The genome database is rapidly growing and is available for scientists all over the world to explore. Its origin can be traced to 1939, when Shannon wrote his PhD thesis, “An Algebra for Theoretical Genetics.”

  Shannon was then a graduate student in the mathematics department at MIT. He was only dimly aware of the possible physical embodiment of genetic information. The true physical embodiment of the genome is the double-helix structure of DNA molecules, discovered by Francis Crick and James Watson fourteen years later. In 1939 Shannon understood that the basis of genetics must be information, and that the information must be coded in some abstract algebra independent of its physical embodiment. Without any knowledge of the double helix, he could not hope to guess the detailed structure of the genetic code. He could only imagine that in some distant future the genetic information would be decoded and collected in a giant database that would define the total diversity of living creatures. It took only sixty years for his dream to come true.

  In the twentieth century, genomes of humans and other species were laboriously decoded and translated into sequences of letters in computer memories. The decoding and translation became cheaper and faster as time went on, the price decreasing and the speed increasing according to Moore’s law. The first human genome took fifteen years to decode and cost about a billion dollars. Now a human genome can be decoded in a few weeks and costs a few thousand dollars. Around the year 2000, a turning point was reached, when it became cheaper to produce genetic information than to understand it. Now we can pass a piece of human DNA through a machine and rapidly read out the genetic information, but we cannot read out the meaning of the information. We shall not fully understand the information until we understand in detail the processes of embryonic development that the DNA orchestrated to make us what we are.

  A similar turning point was reached about the same time in the science of astronomy. Telescopes and spacecraft have evolved slowly, but cameras and optical data processors have evolved fast. Modern sky-survey projects collect data from huge areas of sky and produce databases with accurate information about billions of objects. Astronomers without access to large instruments can make discoveries by mining the databases instead of observing the sky. Big databases have caused similar revolutions in other sciences such as biochemistry and ecology.

  The explosive growth of information in our human society is a part of the slower growth of ordered structures in the evolution of life as a whole. Life has for billions of years been evolving with organisms and ecosystems embodying increasing amounts of information. The evolution of life is a part of the evolution of the universe, which also evolves with increasing amounts of information embodied in ordered structures: galaxies and stars and planetary systems. In the living and in the nonliving world, we see a growth of order, starting from the featureless and uniform gas of the early universe and producing the magnificent diversity of weird objects that we see in the sky and in the rain forest. Everywhere around us, wherever we look, we see evidence of increasing order and increasing information. The technology arising from Shannon’s discoveries is only a local acceleration of the natural growth of information.

  The visible growth of ordered structures in the universe seemed paradoxical to nineteenth-century scientists and philosophers, who believed in a dismal doctrine called the heat death. Lord Kelvin, one of the leading physicists of that time, promoted the heat death dogma, predicting that the flow of heat from warmer to cooler objects will result in a decrease of temperature differences everywhere, until all temperatures ultimately become equal. Life needs temperature differences to avoid being stifled by its waste heat. So life will disappear.

  This dismal view of the future was in startling contrast to the ebullient growth of life that we see around us. Thanks to the discoveries of astronomers in the twentieth century, we now know that the heat death is a myth. The heat death can never happen, and there is no paradox. The best popular account of the disappearan
ce of the paradox is a chapter, “How Order Was Born of Chaos,” in the book Creation of the Universe, by Fang Lizhi and his wife, Li Shuxian.‡ Fang is doubly famous as a leading Chinese astronomer and a leading political dissident. He is now pursuing his double career at the University of Arizona.

  The belief in a heat death was based on an idea that I call the cooking rule. The cooking rule says that a piece of steak gets warmer when we put it on a hot grill. More generally, the rule says that any object gets warmer when it gains energy and gets cooler when it loses energy. Humans have been cooking steaks for thousands of years, and nobody ever saw a steak get colder while cooking on a fire. The cooking rule is true for objects small enough for us to handle. If the cooking rule is always true, then Lord Kelvin’s argument for the heat death is correct.

  We now know that the cooking rule is not true for objects of astronomical size, for which gravitation is the dominant form of energy. The sun is a familiar example. As the sun loses energy by radiation, it becomes hotter and not cooler. Since the sun is made of compressible gas squeezed by its own gravitation, loss of energy causes it to become smaller and denser, and the compression causes it to become hotter. For almost all astronomical objects, gravitation dominates, and they have the same unexpected behavior. Gravitation reverses the usual relation between energy and temperature. In the domain of astronomy, when heat flows from hotter to cooler objects, the hot objects get hotter and the cool objects get cooler. As a result, temperature differences in the astronomical universe tend to increase rather than decrease as time goes on. There is no final state of uniform temperature, and there is no heat death. Gravitation gives us a universe hospitable to life. Information and order can continue to grow for billions of years in the future, as they have evidently grown in the past.

  The vision of the future as an infinite playground, with an unending sequence of mysteries to be understood by an unending sequence of players exploring an unending supply of information, is a glorious vision for scientists. Scientists find the vision attractive, since it gives them a purpose for their existence and an unending supply of jobs. The vision is less attractive to artists and writers and ordinary people. Ordinary people are more interested in friends and family than in science. Ordinary people may not welcome a future spent swimming in an unending flood of information. A darker view of the information-dominated universe was described in the famous story “The Library of Babel,” written by Jorge Luis Borges in 1941.§ Borges imagined his library, with an infinite array of books and shelves and mirrors, as a metaphor for the universe.

  Gleick’s book has an epilogue entitled “The Return of Meaning,” expressing the concerns of people who feel alienated from the prevailing scientific culture. The enormous success of information theory came from Shannon’s decision to separate information from meaning. His central dogma, “Meaning is irrelevant,” declared that information could be handled with greater freedom if it was treated as a mathematical abstraction independent of meaning. The consequence of this freedom is the flood of information in which we are drowning. The immense size of modern databases gives us a feeling of meaninglessness. Information in such quantities reminds us of Borges’s library extending infinitely in all directions. It is our task as humans to bring meaning back into this wasteland. As finite creatures who think and feel, we can create islands of meaning in the sea of information. Gleick ends his book with Borges’s image of the human condition:

  We walk the corridors, searching the shelves and rearranging them, looking for lines of meaning amid leagues of cacophony and incoherence, reading the history of the past and of the future, collecting our thoughts and collecting the thoughts of others, and every so often glimpsing mirrors, in which we may recognize creatures of the information.

  Note added in 2014: Fang Lizhi died in 2012 at the age of seventy-six. Until the end he remained active in his double life as astronomical thinker and political dissident.

  Two corrections to the review: First, the British Enigma project, which deciphered German military codes in World War II, started with crucial help from Polish cryptologists. Before the war began in 1939, the Poles captured a German Enigma machine and gave copies of it to Britain and France. To have the machine was an essential first step toward deciphering the codes. Second, Borges’s “The Library of Babel” was not infinite. The number of books was finite but too large to be counted. I thank two vigilant readers for these corrections.

  *The Information: A History, a Theory, a Flood (Pantheon, 2011).

  †London: Carey Ringsgate, 1949.

  ‡Singapore: World Scientific Publishing Co., 1989.

  §Labyrinths: Selected Stories and Other Writings (New Directions, 1962).

  15

  THE “DRAMATIC PICTURE” OF RICHARD FEYNMAN

  IN THE LAST hundred years, since radio and television created the modern worldwide mass-market entertainment industry, there have been two scientific superstars, Albert Einstein and Stephen Hawking. Lesser lights such as Carl Sagan and Neil deGrasse Tyson and Richard Dawkins have a big public following, but they are not in the same class as Einstein and Hawking. Sagan, Tyson, and Dawkins have fans who understand their message and are excited by their science. Einstein and Hawking have fans who understand almost nothing about science and are excited by their personalities.

  On the whole, the public shows good taste in its choice of idols. Einstein and Hawking earned their status as superstars not only by their scientific discoveries but by their outstanding human qualities. Both of them fit easily into the role of icon, responding to public adoration with modesty and good humor and with provocative statements calculated to command attention. Both of them devoted their lives to an uncompromising struggle to penetrate the deepest mysteries of nature, and both still had time left over to care about the practical worries of ordinary people. The public rightly judged them to be genuine heroes, friends of humanity as well as scientific wizards.

  Two new books now raise the question whether Richard Feynman is rising to the status of superstar. The books are very different in style and in substance. Lawrence Krauss’s Quantum Man is a narrative of Feynman’s life as a scientist, skipping lightly over the personal adventures that have been emphasized in earlier biographies.* Krauss succeeds in explaining in nontechnical language the essential core of Feynman’s thinking. Unlike any previous biographer, he takes the reader inside Feynman’s head and reconstructs the picture of nature as Feynman saw it. This is a new kind of scientific history, and Krauss is well qualified to write it, being an expert physicist and a gifted writer of scientific books for the general public. Quantum Man shows us the side of Feynman’s personality that was least visible to most of his admirers, the silent and persistent calculator working intensely through long days and nights to figure out how nature behaves.

  The other book, Feynman by writer Jim Ottaviani and artist Leland Myrick, is very different.† It is a comic-book biography of Feynman, containing 266 pages of pictures of Feynman and his legendary adventures. In every picture, bubbles of text record Feynman’s comments, mostly taken from stories that he and others had told and published in earlier books. We see Feynman first as an inquisitive five-year-old, learning from his father to question authority and admit ignorance. He asks his father at the playground, “Why does [the ball] keep moving?” His father says, “The reason the ball keeps rolling is because it has ‘inertia.’ That’s what scientists call the reason …, but it’s just a name. Nobody really knows what it means.” His father was a traveling salesman without scientific training, but he understood the difference between giving a thing a name and knowing how it works. He ignited in his son a lifelong passion to know how things work.

  After the scenes with his father, the pictures show Feynman changing gradually through the roles of ebullient young professor and carnival drum-player, doting parent and loving husband, revered teacher and educational reformer, until he ends his life as a wrinkled sage in a losing battle with cancer. It comes as a shock to see myse
lf portrayed in these pages, as a lucky young student taking a four-day ride with Feynman in his car from Cleveland to Albuquerque, sharing with him some unusual lodgings and entertained by an unending stream of his memorable conversation.

  One of the incidents in Feynman’s life that displayed his human qualities sharply was his reaction to the news in 1965 that he had won a Nobel Prize. When the telephone call came from Stockholm, he made remarks that appeared arrogant and ungrateful. He said he would probably refuse the prize, since he hated formal ceremonies and particularly hated the pompous rituals associated with kings and queens. His father had told him when he was a kid, “What are kings anyway? Just guys in fancy clothes.” He would rather refuse the prize than be forced to dress up and shake hands with the king of Sweden.

  But after a few days, he changed his mind and accepted the prize. As soon as he arrived in Sweden, he made friends with the Swedish students who came to welcome him. At the banquet when he officially accepted the prize, he gave an impromptu speech, apologizing for his earlier rudeness and thanking the Swedish people with a moving personal account of the blessings that the prize had brought to him.

  Feynman had looked forward to meeting Sin-Itiro Tomonaga, the Japanese physicist who shared the Nobel Prize with him. Tomonaga had independently made some of the same discoveries as Feynman, five years earlier, in the total isolation of wartime Japan. He shared with Feynman not only ideas about physics but also experiences of personal tragedy. In the spring of 1945, Feynman was nursing his beloved first wife, Arline, through the last weeks of her life as he watched her die from tuberculosis. In the same spring, Tomonaga was helping a group of his students to survive in the ashes of Tokyo, after a firestorm devastated the city and killed an even greater number of people than the nuclear bomb would kill in Hiroshima four months later. Feynman and Tomonaga shared three outstanding qualities: emotional toughness, intellectual integrity, and a robust sense of humor.