The Greatest Story Ever Told--So Far by Lawrence M. Krauss by Lawrence M. Krauss - Read Online

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The Greatest Story Ever Told--So Far - Lawrence M. Krauss

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The hardest thing of all to see is what is really there.


In the beginning there was light.

But more than this, there was gravity.

After that, all hell broke loose. . . .

This is how the story of the greatest intellectual adventure in history might properly be introduced. It is a story of science’s quest to uncover the hidden realities underlying the world of our experience, which required marshaling the very pinnacle of human creativity and intellectual bravery on an unparalleled global scale. This process would not have been possible without a willingness to dispense with all kinds of beliefs and preconceptions and dogma, scientific and otherwise. The story is filled with drama and surprise. It spans the full arc of human history, and most remarkably, the current version isn’t even the final one—just another working draft.

It’s a story that deserves to be shared far more broadly. Already in the first world, parts of this story are helping to slowly replace the myths and superstitions that more ignorant societies found solace in centuries or millennia ago. Nevertheless, thanks to the directors George Stevens and David Lean, the Judeo-Christian Bible is still sometimes referred to as the greatest story ever told. This characterization is astounding because, even allowing for the frequent sex and violence, and a bit of poetry in the Psalms, the Bible as a piece of literature arguably does not compare well to the equally racy but less violent Greek and Roman epics such as the Aeneid or the Odyssey—even if the English translation of the Bible has served as a model for many subsequent books. Either way, as a guide for understanding the world, the Bible is pathetically inconsistent and outdated. And one might legitimately argue that as a guide for human behavior large swaths of it border on the obscene.

In science, the very word sacred is profane. No ideas, religious or otherwise, get a free pass. For this reason the pinnacle of the human story did not conclude with a prophet’s sacrifice two thousand years ago, any more than it did with the death of another prophet six hundred years later. The story of our origins and our future is a tale that keeps on telling. And the story is getting more interesting all the time, not due to revelation, but due to the steady march of scientific discovery.

Contrary to many popular perceptions, this scientific story also encompasses both poetry and a deep spirituality. But this spirituality has the additional virtue of being tied to the real world—and not created in large part to appease our hopes and dreams.

The lessons of our exploration into the unknown, led not by our desires, but by the force of experiment, are humbling. Five hundred years of science have liberated humanity from the shackles of enforced ignorance. By this standard, what cosmic arrogance lies at the heart of the assertion that the universe was created so that we could exist? What myopia lies at the heart of the assumption that the universe of our experience is characteristic of the universe throughout all of time and space?

This anthropocentrism has fallen by the wayside as a result of the story of science. What replaces it? Have we lost something in the process, or as I shall argue, have we gained something even greater?

I once said at a public event that the business of science is to make people uncomfortable. I briefly regretted the remark because I worried that it would scare people away. But being uncomfortable is a virtue, not a hindrance. Everything about our evolutionary history has primed our minds to be comfortable with concepts that helped us survive, such as the natural teleological tendency children have to assume objects exist to serve a goal, and the broader tendency to anthropomorphize, to assign agency to lifeless objects, because clearly it is better to mistake an inert object for a threat than a threat for an inert object.

Evolution didn’t prepare our minds to appreciate long or short timescales or short or huge distances that we cannot experience directly. So it is no wonder that some of the remarkable discoveries of the scientific method, such as evolution and quantum mechanics, are nonintuitive at best, and can draw most of us well outside our myopic comfort zone.

This is also what makes the greatest story ever told so worth telling. The best stories challenge us. They cause us to see ourselves differently, to realign our picture of ourselves and our place in the cosmos. This is not only true for the greatest literature, music, and art. It is true of science as well.

In this sense it is unfortunate that replacing ancient beliefs with modern scientific enlightenment is often described as a loss of faith. How much greater is the story our children will be able to tell than the story we have told? Surely that is the greatest contribution of science to civilization: to ensure that the greatest books are not those of the past, but of the future.

Every epic story has a moral. In ours, we find that letting the cosmos guide our minds through empirical discovery can produce a great richness of spirit that harnesses the best of what humanity has to offer. It can give us hope for the future by allowing us to enter it with our eyes open and with the necessary tools to actively participate in it.

•  •  •

My previous book, A Universe from Nothing, described how the revolutionary discoveries over the past hundred years have changed the way we understand our evolving universe on its largest scales. This change has led science to begin to directly address the question Why is there something rather than nothing?—which was formerly religious territory—and rework it into something less solipsistic and operationally more useful.

Like A Universe from Nothing, this story also originated in a lecture I presented, in this case at the Smithsonian Institution in Washington, DC, which generated some excitement at the time, and as a result I was once again driven to elaborate upon the ideas I started to develop there. In contrast to A Universe from Nothing, in this book I explore the other end of the spectrum of our knowledge and its equally powerful implications for understanding age-old questions. The profound changes over the past hundred years in the way we understand nature at its smallest scales are allowing us to similarly co-opt the equally fundamental question Why are we here?

We will find that reality is not what we think it is. Under the surface are weird, counterintuitive, invisible inner workings that can challenge our preconceptions of what makes sense as much as a universe arising from nothing might.

And like the conclusion I drew in my last book, the ultimate lesson from the story I will tell here is that there is no obvious plan or purpose to the world we find ourselves living in. Our existence was not preordained, but appears to be a curious accident. We teeter on a precarious ledge with the ultimate balance determined by phenomena that lie well beneath the surface of our experience—phenomena that don’t rely in any way upon our existence. In this sense, Einstein was wrong: God does appear to play dice with the universe, or universes. So far we have been lucky. But like playing at the craps table, our luck may not last forever.

•  •  •

Humanity took a major step toward modernity when it dawned in our ancestors’ consciousness that there is more to the universe than meets the eye. This realization was probably not accidental. We appear to be hardwired to need a narrative that transcends and makes sense of our own existence, a need that was probably intimately related to the rise of religious belief in early human societies.

By contrast, the story of the rise of modern science and its divergence from superstition is the tale of how the hidden realities of nature were uncovered by reason and experiment through a process in which seemingly disparate, strange, and sometimes threatening phenomena were ultimately understood to be connected just beneath the visible surface. Ultimately these connections dispelled the goblins and fairies that had earlier spawned among our ancestors.

The discovery of connections between otherwise seemingly disparate phenomena is, more than any other single indicator, the hallmark of progress in science. The many classic examples include Newton’s connection of the orbit of the Moon to a falling apple; Galileo’s recognition that vastly different observed behaviors for falling objects obscure that they are actually attracted to the earth’s surface at the same rate; and Darwin’s epic realization that the diversity of life on Earth could arise from a single progenitor by the simple process of natural selection. None of these connections was all that obvious, at first. However, after the relationship comes to light and becomes clear, it prompts an Aha! experience of understanding and familiarity. One feels like saying, I should have thought of that!

Our modern picture of nature at its most fundamental scale—the Standard Model, as it has become called—contains an embarrassment of riches, connections that are far removed from the realm of everyday experience. So far removed that it is impossible without some grounding to make the leap in one step to visualize them.

Not surprisingly, such a single leap never occurred historically, either. A series of remarkable and unexpected and seemingly unrelated connections emerged to form the coherent picture we now have. The mathematical architecture that has resulted is so ornate that it almost seems arbitrary. Aha! is usually the furthest thing from the lips of the noninitiated when they hear about the Higgs boson or Grand Unification of the forces of nature.

To move beyond the surface layers of reality, we need a story that connects the world we know with the deepest corners of the invisible world all around us. We cannot understand that hidden world with intuitions based solely on direct sensation. That is the story I want to tell here. I will take you on a journey to the heart of those mysteries that lie at the edge of our understanding of space, time, and the forces that operate within them. My goal is not to unnecessarily provoke or offend, but to prod you, just as we physicists ourselves have been prodded and dragged by new discoveries into a new reality that is at once both uncomfortable and uplifting.

Our most recent discoveries about nature’s fundamental scales have chillingly altered our perception of the inevitability of our presence in the universe. They provide evidence too that the future will no doubt be radically different from what we might otherwise have imagined, and they too further decrease our cosmic significance.

We might prefer to deny this uncomfortable, inconvenient reality, this impersonal, apparently random universe, but if we view it in another context, all of this need not be depressing. A universe without purpose, which is the way it is as far as I can tell, is far more exciting than one designed just for us because it means that the possibilities of existence are so much more diverse and far ranging. How invigorating it is to find ourselves with an exotic menagerie to explore, with laws and phenomena that previously seemed beyond our wildest dreams, and to attempt to untangle the knotted confusion of experience and to search for some sense of order beneath. And how fascinating it is to discover that order, and to piece together a coherent picture of the universe on scales far beyond those that we may ever directly experience—a picture woven together by our ability to predict what will happen next, and the consequent ability to control the environment around us. How lucky to have our brief moment in the Sun. Every day that we discover something new and surprising, the story gets even better.

Part One


Chapter 1


The simple inherit folly, but the prudent are crowned with knowledge.


In my beginning there was light.

Surely there was light at the beginning of time, but before we can get to the beginning of time, we will need to explore our own beginnings, which also means exploring the beginning of science. And that means returning to the ultimate motive for both science and religion: the longing for something else. Something beyond the universe of our experience.

For many people, that longing translates into something that gives meaning and purpose to the universe and extends to a longing for some hidden place that is better than the world in which we live, where sins are forgiven, pain is absent, and death does not exist. Others, however, long for a hidden place of a very different sort, the physical world beyond our senses, the world that helps us understand how things behave the way they do, rather than why. This hidden world underlies what we experience, and the understanding of it gives us the power to change our lives, our environment, and our future.

The contrast between these two worlds is reflected in two very different works of literature.

The first, The Lion, the Witch and the Wardrobe, by C. S. Lewis, is a twentieth-century children’s fantasy with decidedly religious overtones. It captures a childhood experience most of us have had—looking under the bed or in the closet or in the attic for hidden treasure or evidence that there is more out there than what we normally experience. In the book, several schoolchildren discover a strange new world, Narnia, by climbing into a large wardrobe in the country house outside London where they have been sequestered for their protection during the Second World War. The children help save Narnia with the aid of a lion, who lets himself be humiliated and sacrificed, Christlike, at an altar in order to conquer evil in his world.

While the religious allusion in Lewis’s story is clear, we can also interpret it in another way—as an allegory, not for the existence of God or the devil, but rather for the remarkable and potentially terrifying possibilities of the unknown, possibilities that lie just beyond the edge of our senses, just waiting for us to be brave enough to seek them out. Possibilities that, once revealed, may enrich our understanding of ourselves or, for some who feel a need, provide a sense of value and purpose.

The portal to a hidden world inside the wardrobe is at once safe, with the familiar smell of oft-worn clothes, and mysterious. It implies the need to move beyond classical notions of space and time. For if nothing is revealed to an observer who is in front of or behind the wardrobe, and something is revealed only to someone inside, then the space experienced inside the wardrobe must be far larger than that seen from its outside.

Such a concept is characteristic of a universe in which space and time can be dynamical, as in the General Theory of Relativity, where, for example, from outside the event horizon of a black hole—that radius inside of which there is no escape—a black hole might appear to comprise a small volume, but for an observer inside (who has not yet been crushed to smithereens by the gravitational forces present), the volume can look quite different. Indeed, it is possible, though beyond the domain where we can perform reliable calculations, that the space inside a black hole might provide a portal to another universe disconnected from our own.

But the central point I want to return to is that the possibility of universes beyond our perception seems to be tied, in the literary and philosophical imagination, at least, to the possibility that space itself is not what it seems.

The harbinger of this notion, the ur story if you will, was written twenty-three centuries before Lewis penned his fantasy. I refer to Plato’s Republic, and in particular to my favorite section, the Allegory of the Cave. But in spite of its early provenance, it illuminates more directly and more clearly both the potential necessity and the potential perils of searching for understanding beyond the reach of our immediate senses.

In the allegory, Plato likens our experience of reality to that of a group of individuals who live their entire lives imprisoned inside a cave, forced to face a blank wall. Their only view of the real world is that wall, which is illuminated by a fire behind them, and on which they see shadows moving. The shadows come from objects located behind them that the light of the fire projects on the wall.

I show the drawing below, which came from the high school text in which I first read this allegory, in a 1961 translation of Plato’s dialogues.

The drawing is amusing because it clearly reflects as much about the time it was drawn as it does the configuration of the cave described in the dialogue. Why, for example, are the prisoners here all women, and scantily clad ones at that? In Plato’s day, any sexual allusion might easily have displayed young boys.

Plato argues that the prisoners will view the shadows as reality and even give them names. This is not unreasonable, and it is, in one sense, as we shall soon see, a very modern view of what reality is, namely that which we can directly measure. My favorite definition of reality still is that given by the science fiction writer Philip K. Dick, who said, Reality is that which, when you stop believing in it, doesn’t go away. For the prisoners, the shadows are what they see. They are also likely to hear only the echoes of noises made behind them as the sounds bounce off the wall.

Plato likened a philosopher to a prisoner who is freed from bondage and forced, almost against his will, to not only look at the fire, but to move past it, and out to the daylight beyond. First, the poor soul will be in distress, with the glare of the fire and the sunshine beyond the cave hurting his eyes. Objects will appear completely unfamiliar; they will not resemble their shadows. Plato argues that the new freeman may still imagine the shadows that he is used to as truer representations than the objects themselves that are casting the shadows.

If the individual is reluctantly dragged out into the sunshine, ultimately all of these sensations of confusion and pain will be multiplied. But eventually, he will become accustomed to the real world, will see the stars and Moon and sky, and his soul and mind will be liberated of the illusions that had earlier governed his life.

If the person returns to the cave, Plato argues, two things would happen. First, because his eyes would no longer be accustomed to the darkness, he would be less able to distinguish the shadows and recognize them, and his compatriots would view him as handicapped at best, and dim at worst. Second, he would no longer view the petty and myopic priorities of his former society, or the honors given to those who might best recognize the shadows and predict their future, as worthy of his respect. As Plato poetically put it, quoting from Homer:

Better to be the poor servant of a poor master, and to endure anything, rather than think as they do and live after their manner.

So much for those whose lives are lived entirely in illusion, which Plato suggests includes most of humanity.

Then, the allegory states that the journey upward—into the light—is the ascent of the soul into the intellectual world.

Clearly in Plato’s mind only a retreat to the purely intellectual world, a journey reserved for the few—aka philosophers—could replace illusion with reality. Happily, that journey is far more accessible today using the techniques of science, which combine reason and reflection with empirical inquiry. Nevertheless, the same challenge remains for scientists today: to see what is behind the shadows, to see that which, when you drop your preconceptions, doesn’t disappear.

While Plato doesn’t explicitly mention it, not only would his fellow prisoners view the poor soul who had ventured out and returned as handicapped, but they would likely think he was crazy if he talked about the wonders that he had glimpsed: the Sun, the Moon, lakes, trees, and other people and their civilizations.

This idea is strikingly modern. As the frontiers of science have moved further and further away from the world of the familiar and the world of common sense as inferred from our direct experience, our picture of the reality underlying our experience is getting increasingly difficult for us to comprehend or accept. Some find it more comforting to retreat to myth and superstition for guidance.

But, we have every reason to expect that common sense, which first evolved to help us cope with predators in the savannas of Africa, might lead us astray when we attempt to think about nature on vastly different scales. We didn’t evolve to intuitively understand the world of the very small, the very big, or the very fast. We shouldn’t expect the rules we have come to rely on for our daily lives to be universal. While that myopia was useful from an evolutionary perspective, as thinking beings we can move beyond it.

In this regard, I cannot resist quoting one last admonition in Plato’s allegory:

In the world of knowledge the idea of good appears last of all and is seen only with an effort; and, when seen, is also inferred to be the author of all things good and right, parent of light, and . . . the immediate source of reason and truth.

Plato further argues that this is what those who would act rationally should strive for, in both public and private life—seeking the good by focusing on reason and truth. He suggests that we can only do so by exploring the realities that underlie the world of our direct experience, rather than by exploring the illusions of a reality that we might want to exist. Only through rational examination of what is real, and not by faith alone, is rational action—or good—possible.

Today, Plato’s vision of pure thought has been replaced by the scientific method, which, based on both reason and experiment, allows us to discover the underlying realities of the world. Rational action in public and private life now requires a basis in both reason and empirical investigation, and it often requires a departure from the solipsistic world of our direct experience. This principle is the source of most of my own public activism in opposition to government policies based on ideology rather than evidence, and it is also probably why I respond so negatively to the concept of the sacred—implying as it does some idea or admonition that is off-limits to public questioning, exploration, discussion, and sometimes ridicule.

It is hard to state this view more strongly than I did in a New Yorker piece: Whenever scientific claims are presented as unquestionable, they undermine science. Similarly, when religious actions or claims about sanctity can be made with impunity in our society, we undermine the basis of modern secular democracy. We owe it to ourselves and to our children not to give a free pass to governments—totalitarian, theocratic, or democratic—that endorse, encourage, enforce, or otherwise legitimize the suppression of open questioning in order to protect ideas that are considered ‘sacred.’ Five hundred years of science have liberated humanity from the shackles of enforced ignorance.

Philosophical reflections aside, the prime reason I am introducing Plato’s cave here is that it can provide a concrete example of the nature of the scientific discoveries at the heart of the story I want to tell.

Imagine a shadow that our prisoners might see on the wall, displayed by an evil puppeteer located on a ledge in front of the fire:

This shadow displays both length and directionality, two concepts that we, who are not confined to the cave, take for granted.

However, as the prisoners watch, this shadow changes:

Later it looks like this:

And again later like this:

And later still, like this:

What would the prisoners infer from all of this? Presumably, that concepts such as length or direction have no absolute meaning. The objects in their world can change both length and directionality arbitrarily. In the reality of their direct experience, neither length nor directionality appears to have significance.

What will the natural philosopher, who has escaped to the surface to explore the richer world beyond the shadows, discover? He will see that the shadow is first of all just a shadow: a two-dimensional image on the wall cast from a real, three-dimensional object located behind the prisoners. He will see that the object has a fixed length that never changes, and that it’s accompanied by an arrow that is always on the same side of the object. From a vantage point slightly above the object, he sees that the series of images results from the projection of a rotating weather vane onto the wall:

When he returns to join his former colleagues, the philosopher-scientist can explain that an absolute quantity called length doesn’t change over time, and that directionality can be assigned unambiguously to certain objects as well. He will tell his friends that the real world is three-dimensional, not two-dimensional, and that once they understand, all of their confusion about the seemingly arbitrary changes will disappear.

Would they believe him? It would be a tough sell because they won’t have an intuitive idea of what a rotation is (after all, with an intuition based purely on two-dimensional experience, it would likely be difficult to picture mentally any rotations in a third dimension). Blank stares? Probably. The loony bin? Maybe. However, he might win over the community by stressing attractive characteristics associated with his claim: behavior that on the surface appears to be complex and arbitrary can be shown to result from a much simpler underlying picture of nature, and seemingly disparate phenomena are actually connected and can be part of a unified whole.

Better still, he could make predictions that his friends could test. First, he could argue that, if the apparent change in length of the shadows measured by the group is really due to a rotation in a third dimension, whenever the length of the object briefly vanishes, it will immediately reemerge with the arrow pointing in the opposite direction. Second, he could argue that as the length oscillates, the maximum length of the shadow when the arrow is pointing in one direction will always be exactly the same as the maximum length of the shadow when it is pointing in the other direction.

Plato’s cave thus becomes an allegory for far more than he may have intended. Plato’s freed man discovers the hallmarks of the remarkable true story of our own struggle to understand nature on its most fundamental scales of space, time, and matter. We too have had to escape the shackles of our prior experience to uncover profound and beautiful simplifications and predictions that can be as terrifying as they are wonderful.

But just as the light beyond Plato’s cave is painful to the eyes at first, with time it becomes mesmerizing. And once witnessed, there is no going back.

Chapter 2


Let there be light: and there was light.


In the beginning there was light.

It is no coincidence that the ancients imagined in Genesis that light was created on the first day. Without light, there would be little awareness of the vast universe surrounding us. When we nod and say, I see, to a friend who is trying to explain something, we convey far more than just an observation, but rather a fundamental understanding.

Plato’s allegory was appropriately centered on light—light from a fire to cast the shadows on the cave wall and light from the outside to temporarily blind the freed prisoner and then illuminate the real world for him. Like the prisoners in the cave, we too are prisoners of light—almost everything we learn about the world we learn from what we see.

While the most significant words in the Western religious canon may be Let there be light, in the modern world this phrase now has a completely different significance from what it once did. Human beings may be prisoners of light, but so is the universe. What once appeared as a whim of a Judeo-Christian God, or other gods before that one, we now understand to be required