In Jorge Luis Borges’s story “The Book of Sand,” a mysterious stranger knocks on the door of the narrator and offers to sell him a Bible he came by in a small village in India. The book shows the wear of many hands. The stranger says that the illiterate peasant who gave him the book called it the Book of Sand, “because neither sand nor this book has a beginning or an end.” Opening the volume, the narrator finds that its pages are rumpled and badly set, with an unpredictable Arabic numeral in the upper corner of each page. The stranger suggests that the narrator try to find the first page. It is impossible. No matter how close to the beginning he explores, several pages always remain between the cover and his hand. “It was as though they grew from the very book.” The stranger then asks the narrator to find the end of the book. Again, he fails. “It can’t be,” says the narrator. “It can’t be, but it is,” says the Bible peddler. “The number of pages in this book is literally infinite. No page is the first page; no page is the last.” The stranger pauses and reflects. “If space is infinite, we are anywhere, at any point in space. If time is infinite, we are at any point in time.” (Note to the observant reader: We cannot be at any point in time. Life can exist only during a relatively short period of cosmic history, as discussed in the last chapter.)
Thoughts of the infinite have mesmerized and confounded human beings through the millennia. For mathematicians, infinity is an intellectual playground, where an endless string of fractions can add up to 1. For astronomers, the question is whether outer space goes on and on and on and on ad infinitum. And if it does, as cosmologists now believe, unsettling consequences abound. For one, there should be an infinite number of copies of each of us somewhere out there in the cosmos. Because even a situation of minuscule probability—like the creation of a particular individual’s exact arrangement of atoms—when multiplied by an infinite number of trials, repeats itself an infinite number of times. Infinity multiplied by any number (except 0) equals infinity.
Measurements of infinity are impossible, or at least impossible according to the usual notions of size. If you cut infinity in half, each half is still infinite. If a weary traveler arrives at a fully occupied hotel of infinite size, no problem. You simply move the guest in room 1 into room 2, the guest in room 2 into room 3, and so on ad infinitum. In the process, you’ve accommodated all of the previous guests and freed up room 1 for the new arrival. There’s always room at the infinity hotel.
We can play games with infinity, but we cannot visualize infinity. By contrast, we can visualize flying horses. We’ve seen horses, and we’ve seen birds, so we can mentally implant wings on a horse and send it aloft. Not so with infinity. The unvisualizability of infinity is part of its mystique.
The first recorded conception of infinity seems to have occurred around 600 BC and is attributed to the Greek philosopher Anaximander, who used the word apeiron, meaning “unbounded” or “limitless.” For Anaximander, the Earth and the heavens and all material things were caused by the infinite, although infinity itself was not a material substance. Other ancient Greek philosophers held that infinity was a negative, even an evil, because the inability to measure a thing was considered a shortcoming of the thing—with the exception of the infinite and immeasurable One. About the same time as Anaximander, the Chinese employed the word wuji, meaning “boundless,” and wuqiong, meaning “endless,” and believed that the infinite was very close to nothingness. (An interesting perspective on Pascal’s ideas, discussed in “Between Nothingness and Infinity.”) In Chinese thought, being and nonbeing, like yin and yang, are in harmony with each other—thus the kinship of infinity and nothingness. A few centuries later, Aristotle argued that infinity does not actually exist. He conceded something he called potential infinity, such as the whole numbers. For any number, you can always create a bigger number by adding one to it. This process can continue as long as your stamina holds out, but you can never get to infinity.
Indeed, one of the many intriguing properties of infinity is that you can’t get there from here. Infinity is not simply more and more of the finite. It seems to be of a completely different nature, although pieces of it may appear finite, like large numbers, or like large volumes of space. Infinity is a thing unto itself. All we see and experience has limits, boundaries, tangibilities. Not so with infinity. For similar reasons, St. Augustine, Spinoza, and other theological thinkers have associated infinity with God: the unlimited power of God, the unlimited knowledge of God, the unboundedness of God. “God is everywhere, and in all things, inasmuch as He is boundless and infinite,” said St. Thomas Aquinas.
Beyond the religious sphere of the immaterial world, physicists believe that there may be infinite things in the material world as well. But this belief can never be proven. You can’t get there from here.
Most of us have our first glimmerings of infinity as children, when we look up at the night sky for the first time. Or when we go to sea, out of sight of land, and gaze upon the ocean extending on and on until it meets the horizon. But these are only glimmerings, like counting to a few thousand in Aristotle’s potential infinity. We’re overwhelmed. But we haven’t come close.
The concept of infinity remains a controversial and paradoxical topic today, galvanizing international conferences and heated scholarly disputes. Can physical forces ever be infinite in strength? Can physical space extend beyond galaxy after galaxy without limit? Is there an infinity between the infinity of the whole numbers and the infinity of all numbers? In May 2013, a panel of scientists and mathematicians gathered in New York City to discuss the profound conundrums surrounding infinity. William Hugh Woodin, a mathematician at the University of California, Berkeley, put it this way: “It’s kind of like mathematics lives on a stable island—we’ve built a solid foundation. Then, there’s the wild land out there. That’s infinity.”
The person on planet Earth who may have come up with the most expansive conception of spatial infinity is the theoretical physicist Andrei Linde, a professor at Stanford University. Professor Linde works only with pencil and paper. Now seventy-two years old, he was born and grew up in Moscow and received his PhD in physics there from the Lebedev Physical Institute. Both of his parents were physicists. He married a physicist, Renata Kallosh (also a professor at Stanford). In 1990, Linde and Kallosh moved to the United States, where he took up his current academic position.
In the early 1980s, Linde proposed a radical theory of the origin of the universe. Linde’s theory, a revision of MIT physicist Alan Guth’s 1981 theory, itself a revision of the 1927 Big Bang model, is called “eternal chaotic inflation.” The theory posits that in its infancy, our universe went through a period of highly rapid expansion, much faster than in the standard Big Bang model. In a tiny fraction of a second, a region of space smaller than an atom “inflated” to a size large enough to encompass all of the matter and energy that we can see today. That much of the inflation theory was articulated in Guth’s paper. Linde’s theory goes further. It predicts that our universe is necessarily one of a vast number of universes, each of which is constantly and randomly spawning new universes in an unending chain of cosmic creation, extending into the future for eternity. Some of those universes, and perhaps our own, should be infinite in extent. In our particular universe, the period of highly rapid expansion would have been completed and done with when our universe was 0.00000000000000000000000000000001 seconds old.
It would be easy to dismiss such speculations as science fiction. But the fantastic speculations of scientists have often found a grip on reality. Two hundred years ago, who would have thought we would be able to decipher the microscopic chemical code that creates living organisms and to alter that code as if rearranging a deck of cards? Or build tiny boxes that could communicate pictures and voices through space? Linde’s speculations are backed up by serious equations, and a number of important predictions of the Guth-Linde inflation theory (but not the existence of infinity) have been confirmed by experiment.
In the scientific community, Linde is widely regarded as a physicist of the first rank. He has won most of the major prizes in physics except for the Nobel. To name a few: the Dirac medal of the International Center for Theoretical Physics in Trieste (shared with Guth and Paul Steinhardt); the Gruber Prize in cosmology (shared with Guth); the Humboldt Prize in Germany; the Kavli Prize of the Norwegian Academy of Sciences and the Kavli Foundation (shared with Guth and Alexei Starobinsky); the Medal of the Institute of Astrophysics in Paris; and, in 2012, the inaugural Fundamental Physics Prize (shared with Guth and others), which carries an award of $3 million per person, more than twice the prize money of the Nobel.
Linde does not have a small opinion of himself. When I met him the first time, in 1987, a few years after his most important work on the inflation theory, he told me about his discovery with these words: “I easily understood what Guth was trying to do. But I did not understand how it [inflation] could be done, since we have seen that the inhomogeneities [in Guth’s original theory] were large [contradicting observations]. I just had the feeling that it was impossible for God not to use such a good possibility to simplify His work, the creation of the universe…I was simultaneously discussing similar matters with Rubakov [by telephone]…I was sitting in my bathroom, since all my children and my wife were already sleeping at the time…After the whole picture had crystallized, I was very excited. I came to my wife and I woke her up and I said: ‘It seems that I know how the universe originated.’ ”
I visited Linde recently at his home in Stanford, California, to get an update on his theory and its place in our view of the world. Linde and his wife live in a lush neighborhood of winding streets, tropical gardens, and houses set up on hills. He was casually dressed in a black fleece sweater over a black T-shirt, black pants, and sandals with black socks—all in dramatic contrast with his snowy white hair. His English is good but retains a thick Russian accent. We sat at the kitchen table. On the wall, a clock, a map of Tuscany, painted ceramic jars on a shelf. His wife prepared a delicious lunch of tortellini and salad.
First off, I asked Professor Linde if he believes that spatial infinity truly exists. “Do you think dinosaurs truly existed?” he replied and paused. “Everything works as if spatial infinity exists.” Linde is careful with language. He distinguishes between reality, which we can never know, and our models and inferences about reality. Linde has always had a strong interest in philosophy. He remembers having debates with high school classmates about science versus art. One of his teenaged philosophical ideas, and an idea that he has not completely abandoned, was that “feelings” are actual objects. Young Linde theorized that when two people are communicating, verbally or nonverbally, their feeling-objects are shared simultaneously. However, in his science classes he learned that Einstein’s theory of relativity forbids any communication faster than the speed of light. He decided that he had better study physics first, so as not to make such “mistakes.”
I asked Professor Linde how he thought about infinity, whether he attempted to visualize it. “No matter how far you go, you can go farther,” he said. Then he made an analogy to a garden. “But there’s no fence.” A week earlier, Robert Jaffe, a theoretical physicist at MIT, told me that he didn’t find “the concept of infinity as troubling as the concomitant concept of nothingness.” Linde said that he would not be particularly bothered by having many copies of himself in outer space in an infinite universe. However, he did allow that it would be “profoundly significant if their thoughts were the same as mine.”
Anaximander’s conception of infinity was abstract and could not reasonably be associated with physical space. In fact, the early Greek philosophers pictured the cosmos as limited in size, with an outer boundary, although the actual distances were not known. In this picture, often associated with Aristotle, the Earth resided at the center of a set of concentric spheres. Going outward was the sphere of the Moon, then Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. Beyond the sphere of Saturn was the “sphere of the fixed stars,” with each star attached to this shell like a bulb on a spherical Christmas tree. And beyond this stellar sphere was the last and outermost sphere, the “primum mobile” (“first moved”), spun by the finger of God. In the sixteenth century, Copernicus changed almost everything by putting the Sun at the center of the solar system. But the Polish scientist left unchanged the idea of a finite universe. The unquenchable stars still dangled from an outermost sphere.
The first person to postulate in concrete terms a spatially infinite universe seems to have been an English mathematician and astronomer named Thomas Digges (1546–1595). In 1576, Digges published a new edition of his father’s perpetual almanac, A Prognostication Everlasting. With the elder Digges long departed, his son was emboldened to add an unauthorized appendix titled “A Perfit Description of the Caelestiall Orbes according to the most aunciente doctrine of the Pythagoreans, latelye revived by Copernicus and by Geometricall Demonstrations approved.” In that appendix, Digges abolished the sphere of the stars. At the center of his diagram is the face of the Sun, with spiky rays issuing forth. Then the “orbes” of the planets. And beyond this region and extending to the edge of the page are the stars, scattered here and there through infinite space.
About one thing Digges and Copernicus and Aristotle concurred. The cosmos on the whole was at rest—a magnificent and immortal cathedral. The cosmos had existed forever and would exist forever, from the infinite past to the infinite future. This peaceful conception sat quietly for another three hundred years. Even Einstein’s cosmological model of 1917, based on his new theory of gravity, proposed a static and eternal universe.
Then came the Big Bang. In 1927, a Belgian priest and physicist named George Lemaître suggested that the previously observed outward motion of galaxies meant that the universe was expanding. Two years later, Lemaître’s suggestion was confirmed by American astronomer Edwin Hubble, who found that the speed at which other galaxies are flying away from us is proportional to their distance—exactly the result as if all the galaxies were dots painted on an expanding balloon. From the viewpoint of any dot (galaxy), it appears that all the other dots are moving away from it. No dot is the center.
By measuring the rate at which the universe is expanding today, we can estimate when the universe “began,” about fourteen billion years ago. Since that moment, the universe has been expanding, thinning out, and cooling. It is important to note that the balloon analogy is only an analogy. In particular, unlike a balloon, the universe could be infinite in extent. What astronomers mean by the statement that the universe is expanding is that the distance between any two galaxies is increasing with time.
The Big Bang model is more than an idea. It is a detailed set of equations describing how the universe has evolved since t = 0, specifying in quantitative detail such things as the average density and temperature of the universe at each point of time. The model has subsequently been supported by several pieces of evidence. For one, the age of the universe as calculated by its rate of expansion approximately agrees with the age of the oldest stars, calculated by our understanding of the physics of stars. For another, the Big Bang model predicts that there should be a flood of radio waves coming from all directions in outer space, produced when the universe was about 300,000 years old and now having a temperature of about 270 degrees below zero Celsius. That predicted flood of radio waves, called the cosmic background radiation, was discovered in 1965. There are other confirmed predictions as well, such as the observed proportions of the lightest chemical elements. The Big Bang theory does not say whether space and time existed before the cosmic balloon began expanding. That profound question would be left to Linde and others. (See the earlier chapter “What Came Before the Big Bang?”)
Linde would have first heard about the Big Bang model as a university physics student in Moscow in the late 1960s. However, he was trained not as a cosmologist but as a particle physicist, as was Alan Guth. Particle physicists study nature at the smallest sizes, while cosmologists study it at the largest. The two branches of physics seemingly had little to do with each other. But in the early 1970s, Linde became interested in certain phenomena that occur at extremely high temperatures, far beyond what can be created in the laboratory, temperatures that could have existed only in the fantastically hot conditions of the infant universe. Describing one of his theories at this time, a prelude to his work on inflation, Linde said, “At the first glance, this theory seemed to be too exotic. We developed it in 1972, but for two years nobody believed us. People were laughing…” But in 1974, some American physicists confirmed the main conclusions.
This response to Linde’s early work—first doubts and then often acceptance—seems to have been a pattern in his career. In our conversation, we talked about the manner in which scientific theories, and especially maverick theories, are confronted by the scientific community. Linde described what he calls a strong “sociological” effect: the biases and prejudices of scientists, their institutional stature, and, of course, the inherent caution of the scientific enterprise. Linde himself is not a cautious person. His colleagues describe him as someone who shoots from the hip with lots of ideas, some right, some wrong, a person of extreme self-confidence, a showman in his popular lectures and articles.
By the early 1970s some physicists were worrying about problems with the Big Bang model, despite its successes. One troubling concern, for example, is that the cosmic radio waves are highly uniform in temperature, no matter what direction we look. There are two possible explanations for this result: either the universe began in an extremely uniform condition, with all parts at the same temperature, or any initial non-uniformities were smoothed out in time, much as hot and cold water in a bathtub will come to the same temperature by exchanging heat. However, heat exchange takes time. According to the Big Bang model, the far-flung distant parts of the universe we see today would not have had time to exchange heat during the first 300,000 years of the universe, when the cosmic radio waves were created. Thus, the second explanation doesn’t work. On the other hand, the first explanation is considered unpalatable because it sweeps the problem under the rug, saying: “It is what it is because it was what it was.” In general, physicists detest such arguments. They prefer to explain everything in the physical universe as the necessary consequence of a few calculable laws and principles rather than as “accidents” of initial conditions, beyond their ability to calculate.
The Guth-Linde inflation theory solves the puzzle of the cosmic radio waves as well as other problems with the Big Bang model. During the period in the infant universe when space was expanding at blinding speed, a very tiny patch of space, tiny enough that all its parts could have homogenized, would have quickly inflated to encompass today’s entire observable universe. No matter what the initial conditions, inflation would have produced a universe of uniform temperature.
Most importantly, the inflation theory explains why such inflation would occur and includes equations for the various energies and forces involved. The key ingredient of the theory, and the cause of the extremely rapid expansion of the infant cosmos, is a kind of energy called a scalar field. Most energy fields, like gravity, are invisible, yet they can exert forces. Some scalar fields produce a repulsive gravitational force. They push things apart rather than pull things together.
What I call the Guth-Linde theory was developed over a period of several years, from 1979 to 1986, beginning with work by Alexei Starobinsky in Moscow. During that period, there were various versions of the theory, problems arising and fixed, new ideas proposed, and an assortment of other physicists involved.
One of Linde’s ideas is that in the early universe, scalar field energy should be constantly created at various magnitudes, due to quantum effects. A strange aspect of quantum physics is that energy and matter can suddenly appear out of nothing for short periods of time. If you could examine space with a strong enough microscope, you would find that it is constantly fluctuating, seething with ghost-like particles and energies that randomly appear and disappear. Quantum phenomena are normally apparent only in the tiny world of the atom, but near t = 0 the entire observable universe was smaller than an atom. If at a certain point in the infant universe sufficient scalar field energy materialized, its repulsive gravitational effect would cause space to expand so rapidly that an entire universe would be created. Since such quantum fluctuations would be going on at random places and times (the “chaos” in Linde’s eternal chaotic inflation theory), new universes would be constantly forming.
Indeed, Linde’s theory requires that we redefine what we mean by “universe.” Some physicists now take the word to mean a region of space that will be quarantined into the infinite future. This region may have been in contact with other parts of the cosmos in the past but can never communicate with the rest of the cosmos in the future. For all practical purposes, each such region is its own universe. In the mind-bending way in which the geometry of space is altered by gravity according to Einstein, it is possible that there be multiple universes, each infinite in extent. The new universes created by quantum fluctuations are predicted to have a wide range of properties—some might be infinite in extent, others finite; some might have the right conditions to make stars and planets and life; others might be lifeless and unformed deserts of subatomic particles and energy; some might even have different dimensions than our own universe. In this vision, there would be an endless creation of new universes, each with its own Big Bang beginning. Our t = 0 would not be the beginning of space and time in the larger cosmos, only for our particular universe. In Linde’s vision of reality, although everything in our universe passes away, the constellation of universes, continually spawning new universes, would represent a kind of immortality.
In some of his papers, Linde illustrates his eternal chaotic inflation model as a thick hedge of branching bulbs, each bulb a separate universe, connecting to ancestor bulbs and descendant bulbs by thin tubes. The entire collection of universes might be called the “cosmos.” Sometimes, it’s called the “multiverse.” It is startling to look at Linde’s picture and to realize that each bulb represents an entire universe, some containing stars and planets, cities, office buildings, trees, ants or ant-like creatures, sunsets. Unfathomable—yet a human mind has fathomed this thick hedge of the imagination. “It can’t be, but it is,” says the Bible peddler in “The Book of Sand.”
One cannot resist comparing Andrei Linde’s “map of the universes” to the Babylonian Map of the World, one of the oldest known maps ever drawn by human beings, found on a stone tablet in what is present-day Iraq and now housed in the British Museum. In this ancient map of the known world (ca. 600 BC) the city of Babylon is perched on the Euphrates River, flowing north and south. Pictured and named (in Sanskrit) are a few other cities, including Uratu, Susa, Assyria, and Habban; a mountain; and a circular ocean (labeled as “bitter river”) enveloping the inhabited cities. Finally, some unnamed and unknown outer regions represented by spikes radiating out from the circular ocean. Could one compare these unnamed spikes to the unnamed bulbs in Linde’s map? Both lie far beyond the realm of physical exploration. Both require leaps of the imagination. Yet Linde’s bulbs follow as logical consequences of certain mathematical equations. As Linde would acknowledge, those equations are also works of the human imagination, models of reality instead of reality itself. Linde’s ideas are at once visionary and grounded in logical thinking. Although mathematically proficient in the manner of all theoretical physicists, Linde described himself to me as more intuitive than technical, a Steve Jobs more than a Steve Wozniak.
The Babylonian Map of the World is a static picture. By contrast, Linde’s Map of the Universes suggests evolution and change, movement. The various universes spawn one another in time. A better comparison, then, might be found in Hindu cosmology, in which our universe is one of an infinite number of cycling universes. The totality has no beginning or end. The concept is described in the Bhagavata Purana:
Every universe is covered by seven layers—earth, water, fire, air, sky, the total energy and false ego—each ten times greater than the previous one. There are innumerable universes besides this one, and although they are unlimitedly large, they move about like atoms in You. Therefore You are called unlimited.
I do not feel unlimited looking at Linde’s Map of the Universes. Instead, I feel small and insignificant, like the Bible peddler who says that if space is infinite, we are nowhere in space, nowhere in time. How can anything we do be of consequence when we are nowhere in space, nowhere in time, when our brief lives are lived out on one small planet, itself one of zillions of planets in a universe that may be infinite in size, and our entire universe simply one bulb in Linde’s thick hedge of universes? On the other hand, there may be something majestic in being a part, even a tiny part, of this unfathomable chain of being, this infinitude of existence. We pass away, our Sun will burn out, our universe may become a dark and lifeless void a hundred billion years from now—but, according to Linde, other universes are constantly being born, some surely with life, renewing something precious that cannot be named.
It is unlikely that we will ever know if Linde’s infinity of universes exists. But the rest of the Guth-Linde inflation theory is being actively tested today. One of the most important tests, Linde explained to me, is a search for something called “B-mode polarization,” a slight twisting pattern in the vibrations of the cosmic radio waves predicted by the inflation theory. A few years ago, astronomers thought they had discovered the phenomenon, an experimental confirmation that would probably have brought Nobels to Linde and Guth. On the morning of Thursday, March 6, 2014, a professor of astrophysics at Stanford named Chao-Lin Kuo knocked on the door of Linde’s home. Dr. Kuo was accompanied by a camera crew. (The resulting video, made by Stanford University, was posted on YouTube eleven days later and has received over three million hits.) When they open the door, Linde and his wife appear stunned at the news. Renata gives Chao-Lin a big hug. Then the cameras follow Linde and Kuo as they go into the kitchen and share a bottle of champagne. We hear the pop of the cork. We see the clock on the wall, the map of Tuscany, the painted ceramic jars on a shelf. “We are talking about a billionth of a billionth of a billionth a millionth of a second after the Big Bang,” says Linde. “Finally, it arrived,” he says with a smile on his face. Eleven days after Dr. Kuo’s visit, headlines appeared all over the world. In a New York Times article titled “Space Ripples Reveal Big Bang Smoking Gun,” cosmologist Marc Kamionkowski of Johns Hopkins University said, “This is huge, as big as it gets.” Max Tegmark, a cosmologist at MIT, said, “I think that if this stays true, it will go down as one of the greatest discoveries in the history of science.” It didn’t stay true. Or rather, the experimental results were correct, but misinterpreted. A follow-up analysis showed that the twisting effect was likely caused by ordinary dust in outer space rather than by the extremely exotic processes predicted by the Guth-Linde inflation theory. That realization did not deflate the theory, but it did leave more work to be done.
Refined measurements of the B-mode polarization, able to distinguish between mundane dust in the Milky Way and cosmic inflation in the infant universe, are now being conducted by the “Polar Bear” experiment in the Atacama Desert of northern Chile and by the “BICEP” experiment at the South Pole, among others. These experiments are international collaborations, including over a dozen institutions in the United States, England, Wales, France, and Canada. Thousands of scientists worldwide, both theorists and experimentalists, are actively working to test the inflation theory and to probe its consequences. Almost all cosmologists today accept it as the best working hypothesis we have of the first moments of our universe. The theory must be considered a triumph of the human mind.
Yet, Andrei Linde does not appear to be a man completely at peace with his place in the world. Something eludes him. When he talks about the history of the inflation theory, he seems to be still defending his ideas against naysayers and rival theorists, still competing with Guth and others for priority of discovery, still infused with a powerful desire for vindication. In my conversations with him and in his review articles and autobiographical statements, he portrays himself as someone who heroically developed a new view of the cosmos, struggled against doubters, corrected other people’s mistakes and misunderstandings, and was often misunderstood himself. One story he enjoys telling is about a lecture that Stephen Hawking gave at the Sternberg Astronomical Institute in Moscow in October 1981. Linde was asked to translate for the Russian audience. At this time, various physicists, including Hawking, were trying to patch up a serious problem (too much inhomogeneity) in Guth’s original inflation theory. Linde had devised his own inflation theory, a revision of Guth’s theory, but it was not yet published. During the lecture, Hawking would mumble a few incoherent words, one of his graduate students familiar with his speech would translate into understandable English, and then Linde would translate into Russian. With this painfully slow process under way, Hawking announced that Linde had a good idea, but that it was wrong. Then for the next half hour, sitting in his wheelchair, he proceeded to explain why it was wrong. All the while, Linde had to translate. At the end of the lecture, Linde told the audience, “I have translated, but I disagree.” He then took Hawking in his wheelchair to another room of the building, closed the door, and explained to him more details of his new theory. Evidently, Hawking had to admit that Linde was right after all. According to Linde, Hawking “was sitting there about one hour and a half and saying to me the same words: ‘But you did not tell this before. But you did not tell this before.’ ”
Perhaps Linde’s ego and bravado were essential for the conception of his phantasmagoric cosmology. Other scientists with equal brainpower but more cautious dispositions have not ventured nearly so far in their theories of the world. The equations are the equations, but they must be imagined and interpreted in the human mind, a particular human mind, a complex universe itself, endlessly variable in its quirks and possibilities.
“At the beginning, I was like a young kid, making discoveries,” Linde told me. “Now I feel a deep responsibility. There are hundreds of people working on the theory of inflation and lots [of expensive] experiments to test it. You feel yourself a bit heavy with responsibility…I would hate to die just being a physicist. I enjoy photography. That allows me to feel another part of my brain. There is something beyond physics that is not measurable…Photography is my art. You need to have a first priority and then a second priority. When I was sixty, someone gave me a camera. With a camera, you can produce beauty. I can produce things that are better than what I see in museums. You see, I am now talking like an arrogant American. I am producing images that make my heart sing—both my photographs and the computer graphics illustrating inflation. I am among the first to see the beauty in it. Without the part of my mind beyond physics, I would be unable to create the computer graphics of cosmology.”
Linde went to his computer and eagerly showed me his Flickr website, where he has posted hundreds of his photographs. “Sit down,” he said and offered me a seat near the screen. One of his photographs, titled Alcazar Dreams, depicts a subterranean pool beneath the Patio del Crucero in Seville, Spain. He explained that the pool was built by the master of the castle for his lady friend. A series of stone arches, glowing in eerie orange light, bend over the elongated pool, one after another after another out to a distant vanishing point. Another image, titled Hide Thy Face, is an extreme close-up of the interior of an orchid. Around the outside edges unfolds a diaphanous blue halo. At the middle of the flower is a two-chambered yellow heart covered with red speckles, with white-and-red-striped arms emerging from it, and farther out pale green and yellow petals. Altogether, an intricate jewel, a tiny splash in infinity.