About Time Read online

  If the time we live by is something new in human evolution, is it real? If other cultures moved through each moment of their days in entirely different ways, then how concrete is 1:17 p.m., with all the import, urgency and meaning we ascribe to it? As we shall see, the time we imagine for the cosmos and the time we imagined into human experience turn out to be woven so tightly together that we have lost the ability to see each of them for what it is.

  Our cosmologies are soaked in time and have shaped the worlds of culture and experience. Our cultures are soaked in time and have shaped our grandest imaginings of cosmology, from myth down to the exacting science and technologies we encounter today. This braiding of science and culture is a story that we are unused to telling. It is easy to think of science as some kind of lumbering giant picking up brute facts and handing them to us in the form of revolutionary technologies (mobile phones, atomic weapons, antibiotics). But the knife-sharp separation of science from other human endeavours such as art, politics and spiritual longing is too abstract to be true or helpful. We want to glimpse the ways our science shapes, and is shaped by, experience and the culture it creates. That task demands we ask the deepest questions of all about the nature of time, the cosmos and their beginnings.

  FROM HERE TO THE BEGINNITY: THE STORY OF SCIENTIFIC COSMOLOGY

  The story of modern cosmology starts now and moves in reverse. That is how we astronomers and physicists have learned to piece together the story of the Big Bang. We begin with what we see around us—galaxies flying apart, carried along with the flow of space and time—an expanding universe. Then we imagine running the film of that expansion backwards. The galaxies crowd together rather than rush apart. Space becomes dense, the galaxies dissolve, and atoms are slammed into each other, reaching towards infinite density. The heat released drives the temperature of the entire universe towards impossible heights, until we are back at that singular moment—the unimaginable beginning when time itself was born.

  The first cosmologies were the myths of our distant ancestors. In their stories of sky gods and mother goddesses, one finds the same explanatory impulse that drives our modern scientific efforts. What is new in our scientific and technological versions of the cosmological narrative is the all-important ability to test our stories against the data. We can ask the universe if we are right and see if it agrees. But Big Bang cosmology is not really one story; it is many. It is an interlocking web of scientific narratives about the nature of reality. Forged in earthbound laboratories, astronomical observatories and the imaginations of theoretical physicists across the last five hundred years, it is a culmination, one of our greatest achievements as a culture. If we are to understand the Big Bang—its triumphs, its failures and the horizon of possibilities that could replace it—we will have to cover a broad landscape of physics and astronomy. We must obtain a complete view of where we are now so that we may be prepared to imagine what comes next.

  To understand the Big Bang and its looming alternatives, we must cover a terrain that has a wild topography of remarkable beauty and range, shaped by nature’s deepest laws. Passing across that landscape, we will, in the chapters that follow, explore the foundations of modern physics—Einstein’s theory of relativity, quantum and particle physics, thermodynamics and astrophysics. We will linger long enough with these fundamental ideas to gain a sense of how the universe has taken the form we see through our eyes and our telescopes.

  Crossing this terrain will take us to the precipice we now face. For all their power, our two greatest theories of physics—quantum mechanics and Einstein’s theory of gravity (called general relativity)—face a single great failing: they cannot talk to each other. The domains of the very small (quantum physics) and the domains of the very large (gravity) cannot be reconciled. After fifty years of trying, we still lack that holy grail of physics, a theory of quantum gravity—a theory of space and time on scales so small entire universes could be bound in an atom. To understand the bang in the Big Bang, we need quantum gravity. Consequently, our cosmology remains incomplete.

  The search for quantum gravity and the ideas it entails will form one part of our story. The problems and paradoxes that have plagued the Big Bang will form the other. To rescue Big Bang cosmology from its own best data, astronomers and physicists were forced to imagine events occurring in the early universe—the barest instants after creation—which have shaken the very concept of a “moment of creation”. Together with the attack on quantum gravity, the rescue of the Big Bang has led to a Wild West of new ideas that throw open the frontiers of space, time and creation. The last part of our story will be the exploration of these frontiers.

  Could there have been not just one bang but recurring ones? Could our universe be only one in a long line of cycles? Could there be many bangs going off all the time, creating an infinite number of simultaneously existing universes—a multiverse of infinite possibilities? Perhaps, more radically still, our entire conception of time is wrong. Perhaps time is an illusion. Perhaps there is no passage from one moment to the next. Once we have gained a view of where we stand now, in the midst of our cherished but ill-fated Big Bang theory, we can explore these and other possibilities as we look to the future of cosmology and our concept of time itself.

  FROM THE BEGINNING TO BEING-HERE-NOW: THE STORY OF HUMAN TIME

  Building cosmologies is an old, old business for us. Myths and religion have conceived of Big Bangs before. But that didn’t make it any less of a surprise when scientists found that their own pathways of investigation led them towards t = 0, with its echoes of a biblical moment of creation. What many of them didn’t know was that even alternative cosmological models had antecedents in mythology and religion.

  The human engagement, construction and invention of time began with our mental awakening. Archaeologist Steven Mithen calls this, appropriately, the “Big Bang of consciousness”, and it remains as mysterious and enigmatic as the origin of the cosmos. Two thousand generations ago, deep in the cold of the last ice age, we humans awoke to the predicament of ourselves in time. In order to cope, we invented new forms of social organization and new ways of thinking that set the species on an unprecedented evolutionary trajectory. We invented culture and in doing so invented ourselves.

  It began some seventy thousand to forty thousand years ago with the burying of the dead. Death has always been a portal to time’s great mystery. By ending time (at least as we know it) for the self, death acts as an invitation to consider time’s reality and its meaning. We felt this even in the early stages of our cultural development. Arranging the departed into huddled postures of repose, we lay our loved ones in graves with precious goods, such as beads and knives, that signified an awareness of death as time. Later, on cave walls and rock cliffs, we began to leave a permanent record of our interior response to the world in art that remains haunting to this day. In these caves covered in paintings of bison and mammoths, archaeologists have also found flutes made of bone, and carvings on bone fragments that seem to trace the phases of the moon. As a species, we awoke not only to symbolic expression through art but also to the explicit experience of time through internal rhythms expressed in music and external rhythms we noticed in the sky.

  Personal time and cosmic time have been linked from the earliest origins of culture. When the development of agriculture followed the retreating glaciers, some twelve thousand years ago, a new sense of time emerged with it. Farming led to surplus and wealth, villages turned into towns, towns turned into cities, and cities grew into empires. In each stage, new encounters with time would emerge that were born directly from the material needs of the culture. It was through a direct, embodied engagement with the material world—what we made, how we made it and how that changed the way we organized ourselves—that time itself changed. Each culture shaped its day-to-day life through the technologies it built and through its “institutional facts”—the invented social reality the technologies allowed and supported.

  But cultures (with their inven
ted institutions) need justification and support. They need to set themselves against a cosmic background to give individual and collective lives meaning. The central theme of this book will be to explore the enigmatic entanglement that tied human time to the cosmological narratives of sky and stars, origins and final endings.

  It is crucial to recognize that each grand change in human history has shifted more than merely ideas about time. Instead, it is the experience of time, its felt contours, that have been transformed. To understand that story, and to see how closely connected our direct encounters with time are to cosmological imaginings about it, we must travel a path parallel to the one we take in our exploration of physics and astronomy. A Palaeolithic farmer moved through his day and experienced time in a radically different way than did a merchant living in the great city of Babylon. The human encounter with time is fluid and malleable. It can and will change again.

  Thus, our story of human time will begin fifty thousand years ago with our hunter-gatherer ancestors and move through experiences of the first farmers and city builders. It will take on new themes as the Renaissance begins and clocks are first introduced to town squares. With the industrial revolution, an entirely new form of time comes to dominate culture, and a new politics follows in its footsteps. As the twentieth century begins, the electrified world gives birth to yet another form of encountered time that presages our own wireless world. Then, with the dawn of the space age and the digital revolution, we arrive at our own home in the age of precision, just-in-time, never-enough-time.

  By recounting the narrative of our time, in step with our emerging understanding of cosmic time, we will be in a better place to see where we are now and what other times we might create.

  We must note that there were (and are) many trajectories of development for human culture. In this book we will focus on the broad sweep of history, science and time but in doing so we focus primarily on the trajectory of cultural development associated with the West. This makes sense, of course, because science and scientific cosmology emerged from traditions born in what historian Ian Morris calls the “Western core”—Mesopotamia, Egypt, Greece and so on.1 We should remain mindful, however, that the traditions that emerged in the Eastern core—China, Korea and others—had their own cultural uses for time and their own cosmological visions for it as well. Now that science has become truly global it may be that our future will see metaphors associated with these other traditions finding their way into cosmological theorizing and the cultural constructions of time. It is a possibility we must not lose sight of as we look forward.

  THE REDISCOVERY OF MAN

  It’s only 9:00 a.m. in Lindos and the sun leans hard on my astronomer friend and me as we climb the narrow steps to the top of the cliff. We slept on the beach last night, knowing it would be the only way to reach the temple before the impossible heat and the crowds arrive.

  Lindos is a small coastal town on the Greek island of Rhodes. Here, some twenty-five hundred years ago, on a granite promontory that rises dozens of metres above the sea, the Greeks built a temple to the goddess Athena. From the beach below it’s a staggering sight—an acropolis hanging in the air. Now, as we reach the top of the stairs and walk out onto the temple grounds, it’s overwhelming.

  We came to this island not as sightseers but for a business that stretches as far back as this temple. All week we have been attending a conference on astronomy. My companion and I both study star formation—a branch of astronomy that focuses on the assembly of stars and planets from vast clouds of dusty interstellar gas. Along with 150 other astronomers, we gathered at a resort hotel on the other side of the island to share new data, new models and new insights into the early lives of stars very much like the one beating its light and heat down on us now. We must have looked odd to tourists, with our penchant for staying indoors all day, huddled in a dark meeting hall, staring at endless sets of PowerPoint slides.

  Locating this conference in Rhodes was not an arbitrary choice for its organizers. Two thousand years ago the city of Rhodes was the home of Hipparchus, the greatest of ancient Greece’s observational astronomers. In the days when this temple was home to priests servicing Athena’s concerns on Earth, Hipparchus was busy in the city cataloging the starry skies.

  I stand under the towering columns of the temple to shield myself from the ferocity of the sun and stare into an impossibly empty sky and an unyieldingly blue Aegean. Here, at a temple where each day would be metered by prayers to the gods, on an island where true astronomical investigation gained an early foothold, the glue binding human and cosmic time seems as concrete as the giant stone columns standing guard over the ocean.

  What began here has been continuously reshaped in a long march leading directly to the cosmos my colleagues and I explored at last week’s meeting. Now all of us—scientist and nonscientist alike—are about to start this march anew even if we do not recognize it. We are ready to end one kind of time and one kind of universe. We are ready to end the beginning and to begin again.

  ABOUT

  TIME

  Chapter 1

  TALKING SKY, WORKING STONE AND LIVING FIELD

  From Prehistory to the Agricultural Revolution

  ABRI BLANCHARD, THE DORDOGNE, FRANCE • 20,000 BCE

  The shaman stands before the opening of the cave and waits. Night is falling now and the piercing cold of autumn easily penetrates her animal-hide cloak. Outside, beyond the sheltering U-shaped bay of low cliff walls, the wind has picked up. These winds originated hundreds of miles to the north at the blue-white wall of glaciers that cover much of northern Europe.1

  Winter is coming and the shaman’s people will have to move soon. The hides and supplies will be gathered and they will begin the trek towards the low-hanging sun and the warmer camps. But tonight the shaman’s mind is fixed on the present and she waits. It is her job to read the signs the living world provides. It is her job to know the turnings of Earth, animal and sky. The shaman’s people depend on this wisdom and so she waits to complete the task her mother suggested before she died. She waits, massaging the reindeer bone fragment in one hand and the pointed shard of flint in the other.

  Now she sees it, the glow over the eastern horizon. The great mother rises. The shaman waits to see the moon’s face—pale, full of power. There, see! She is complete again.

  From the crescent horns of many days ago, she has now returned, completed, to life. The full circle of the moon’s face, promising rebirth and renewal, has returned. The shaman holds the bone fragment before her in the grey light. With her index finger she traces out the long serpentine trail of her previous engravings on the bone. Then at the end of the trail she makes tonight’s mark with the flint-knife, carving the shape of tonight’s full moon into the hard bone.

  Two rounds of the moon’s dying and rebirth have now been traced out. The shaman’s work is complete. The round of life and death in the sky, like the rounds of women’s bleeding, have been given form, remembered, noted and honoured. She returns the bone to its place beneath the rocks where she keeps the other shamanic tools her mother gave her so long ago. Now she has added to the store, a marking of passages, that she will use and pass on to her own children.2

  WANDERING TIME: THE PALAEOLITHIC WORLD

  The origins of human culture are saturated with time but we have only recently learned to see this truth. The evidence of the age when we grew into an awareness of ourselves, the cosmos and time itself had always been just out of reach. For most of our remembered history, the clues to the birth of culture and cultural time lay forgotten, buried a metre or so below the ground. Then, in the late 1870s, the discoveries began and we started to remember.

  We first encountered the great awakening of our consciousness in 1879 in Spain when the nine-year-old daughter of amateur archaeologist Marcelino Sanz de Sautuola led him to a cave at Altamira. Venturing inside, he found its walls covered in vivid paintings now known to be twenty thousand years old. As archaeologists began systematic explo
rations, new caves were discovered, many of them also covered in paintings. The caves are a bestiary: bear, bison and mastodon appear on the walls along with other species. Sometimes these animals appear alone. Other times they are in herds. Sometimes we appear too—human figures set against the herd, spear at the ready.

  FIGURE 1.1. The Recognition of Time. The Abri Blanchard bone fragment (dating back between 12,000 to 20,000 BCE). Archaeologist Alexander Marshack proposed that the distinct pattern of engravings was an early record of lunar cycles.

  These paintings gave voice to a heretofore silent past, showing that early humans were anything but “savages” incapable of representation, abstraction or response. This vivid prehistory, the time before written records, was set into a temporal sequence through painstaking work across the twentieth century. Radiocarbon dating allowed scientists to see when each cave was inhabited and when the paintings were laid down. As the sequence became complete, scientists came to understand how rapidly our ancestors had re-imagined what it meant to be human. With that recognition, conceptions of evolution and the origins of the human mind were thrown open. Scientists began searching for some purchase on a new theory that could explain how the mind rapidly woke to itself and to time.

  Buried next to the painted walls, archaeologists discovered artefacts worked by human hands. There were statues of women with wide hips, pendulous breasts and finely articulated vulvas, seeming to focus on the mysteries of fertility. Spear points, needles, flint daggers and hammers spoke of cultures skilled in the creation of a diverse set of tools for diverse needs. And on the floor of a cave at Abri Blanchard, a rock shelter in the Dordogne region of central France,3 archaeologists found a “small flat ovoid piece of bone pockmarked with stokes and notches . . . just the right size to be held in the palm of the hand”.4