^{Excerpted from Genesis: The Story of How Everything Began by Guido Tonelli (translated from the original by Erica Segre and Simon Carnell). Copyright © 2021 by Guido Tonelli. Published by Farrar, Straus and Giroux. All rights reserved. Reprinted by permission.}

Forty thousand years ago, when the second wave of Homo sapiens arrived from Africa, many areas of Europe were already populated by Neanderthals. Organized into small clans, the Neanderthals lived in caves that today provide unequivocal proof of a complex symbolic universe: walls painted with symbols and drawings of animals, bodies buried in fetal positions, bones and large stalactites arranged in ritual circles; plentiful evidence, in other words, of a culture that had in all probability also developed a sophisticated spoken language.

It is possible, then, to imagine hearing a story of the origins of the world already resounding in those caves, the elders transmitting it to the young through the power of words and the magic of memory: the echo of an ancient narrative. It would be thousands of generations before Hesiod (or whoever we know by that name), left us, in his Theogony, a written account of how our universe came into being, woven from poetry and cosmology.

This ancient origin story continues to evolve to this day, thanks now to the language of science. Equations might lack the evocative power of poetry, but the concepts of modern cosmology—a universe that was born from a fluctuation in the quantum void, or from cosmic inflation—can still take our breath away.

All such stories spring from one simple, inescapable question: “Where does all this come from?” It is a question that still resonates in every part of the world, among people belonging to vastly different cultures. It is a point of commonality in otherwise distant civilizations; a question posed alike by children and executives, scientists and shamans, astronauts, and those small, isolated populations of hunter-gatherers who survive in areas of Borneo, Africa, and the Amazon. A question so primal that some have even imagined it must have been handed down to us by the species that came before.

For the Kuba of the Congo, the universe was created by the great Mbombo, the lord of a dark world who vomited up the Sun, Moon, and stars in order to free himself from a terrible stomachache. According to the Fulani of the African Sahel, it was the hero Doondari who transformed an enormous drop of milk into earth, water, iron, and fire. For the Pygmies of the forests of equatorial Africa, everything came into being when a huge turtle laid its eggs while swimming in the primordial water.

At the origin of mythological narratives of this kind, there always seems to be something indistinct that most troubles us: chaos, darkness, a liquid and formless expanse, a tremendous fog, a desolate Earth—until a supernatural being intervenes to shape things and bring order. This is where the great reptile comes in, the primeval egg, the hero, or the creator who separates the heavens from the Earth, the Sun from the Moon, and gives life to animals and men.

The creation of order is necessary because it establishes the rules, providing the foundations of rhythms that mark the life of communities: the cycles of day and night, the changing seasons. Primitive chaos triggers an ancestral fear: the terror of falling prey to the forces un-leashed by nature—from ferocious beasts and earthquakes to droughts and floods. But once nature is induced to follow the rules dictated by the hero who has brought order to the world, humankind is able to survive and reproduce. The natural order is reflected in the social one, in the combination of norms and taboos that define what is allowed and what is strictly forbidden. If the tribe behaves according to the rules established by that originary pact, then this stockade of rules will protect the community and prevent its disintegration.

From such myths as this, other constructions follow. They morph into religion and philosophy, art and science—disciplines that will hybridize and fertilize each other, and allow enduring civilizations to flower. Yet their interweaving breaks down when science starts to develop out of all proportion to our other speculative activities. From that moment on, the sleepy rhythm of societies, unchanged for centuries, is ruptured by a succession of discoveries that will profoundly alter the existence of untold populations. Suddenly everything changes, and continues to change, at a vertiginous pace.

The emergence of science ushers in modernity. Societies become dynamic, subject to continuous transformations; social groups enter a period of ferment, dominant classes undergo profound changes, and in the course of just a few decades the centuries-old balance of power is disrupted.

But the most profound transformations do not concern the way in which we communicate or produce wealth, our medicine or mobility. The most radical alterations are in how we look at the world, and therefore our place within it. The origin story provided by modern science very quickly acquires an unrivalled consistency and complexity. No other discipline can provide explanations that are more convincing, verifiable, coherent, or consistent with regard to the myriad observations supplied by scientists.

And yet, despite the notion that we have progressively lost something of the magic and mystery that had accompanied us for millennia, the vision of the world that we have gradually developed through science is actually more amazing than anything we could have imagined before. It retells the story of our origins more imaginatively and powerfully than any mythological narrative. In order to construct this story, scientists have had to scrutinize the most hidden and minute corners of reality, and have explored the remotest worlds, coming to terms with states of matter so different from anything previously known to us as to nearly blow  our minds.

From science we derive the paradigm shifts that define our epochs, and that irreversibly modify our relationships. And it is the ceaseless pressure of scientific discoveries that sets the tempo of this subterranean development, like the forces exerted upon the Earth’s crust by white-hot magma, sometimes breaking it apart and irreparably transforming the landscape above.

Our lives are conditioned by the story of the origins of the universe told by science: it profoundly shifts the foundations on which we will build new social arrangements, opening up vistas full of opportunities and risks, and shaping the future for coming generations. This is why, just as in ancient Greece everyone had to know the foundation myths of the polis, the origin story that is provided by science ought to be familiar to everyone. But for this to happen, we must first overcome a considerable obstacle. We need to come to terms with the difficulty of scientific language.

It all begins with an apparently marginal episode that took place just over four hundred years ago, and which has as its protagonist a Pisan professor of geometry and mechanics at the University of Padua. When Galileo Galilei began to modify the strange tube manufactured by a Dutch optician, converting it into an instrument for examining celestial bodies, he could hardly have imagined the trouble it would get him into; much less could he have foreseen the turbulence that his observations would create across the entire planet.

What Galileo sees through his system of lenses astonishes him. The Moon is not, after all, the perfect celestial entity described by the most authoritative texts. It is not composed of incorruptible matter, but has mountains, craters with jag-ged edges, and plains similar to our own. The Sun has stains on its surface and rotates on its axis; the Milky Way is a vast accumulation of individual stars; the “starlets” surrounding Jupiter are orbiting satellites that resemble the Moon.

When in 1610 Galileo publishes all this in his Siderius Nuncius, he provokes, perhaps unwittingly, an avalanche that will undermine the system of beliefs and values that had prevailed for more than a thousand years and that no one had ever dared to challenge.

Modernity begins with Galileo: humankind frees itself from all protection and faces the vastness of the universe alone, armed only with its own ingenuity. A scientist no longer looks for truth in books, no longer bows his head before the principle of authority, no longer repeats formulas handed down by tradition—but subjects everything to the fiercest scrutiny instead. Science becomes creative research into “provisional truths,” through “sensory experiences” and “necessary demonstrations.”

The power of the scientific method resides in conjectures verified by means of instruments that allow the observation, measurement, and categorization of the most diverse natural phenomena. It is the results of these experiments, what Galileo calls “sensory experiences,” that determine whether a conjecture works or should be discarded. 

From his observations, irrefutable evidence is soon provided in support of the “lunatic” theories of Copernicus and Kepler, and our view of the world changes so radically that nothing will ever seem the same again. Art, ethics, religion, philosophy, politics—everything will emerge transformed by this conceptual revolution that places humankind and its capacity for reasoning at the center of everything. The disorientations that this new approach will produce, in a relatively brief period of time, are so profound that it is hard to think of anything remotely comparable.

Galilean science is truly revolutionary because it does not allow itself the right to hold back the truth, but instead relentlessly seeks the possibility of falsification even in its own predictions; it welcomes the prospect of all the certainties established up to that point crumbling if they turn out to be false, and it is self-correcting in the light of experimental verification. Finally, in order to stress-test the increasingly complex conjectures that are being elaborated in its name, it pushes towards the exploration of ever more mysterious aspects of matter and of the universe.

From this patient and self-critical approach, accounts are produced of elusive and apparently marginal phenomena. In the process of evolving a view of the world that is ever more sophisticated and complete, we end up mastering, down to the minutest detail, the most remote natural phenomena—and at the same time developing increasingly sophisticated new technologies.

The price to be paid for this course of development is the need to use increasingly complex instruments, and a language increasingly remote from common speech. No sooner have we departed from the realm of daily life than the instruments and conceptual apparatus that govern our ordinary activities become inadequate. When we explore the minuscule dimensions in which the secrets of matter tend to be hidden, or embark on an exploration of those cosmic spaces that tell of the origins of the universe, we find ourselves in need of very special equipment and years of preparation.

This should come as no surprise. Even actual journeys of exploration and adventure across the globe require a great deal of preparation, effort, and specialized equipment. Think of extreme sailing, or climbing in the Himalayas, or descending into the oceanic abyss. Why should scientific exploration be any easier?
Anyone wishing to thoroughly appreciate physics, therefore, will need to labor for years, to study group theory and differential calculus, and gain a command of relativity and quantum mechanics, as well as field theory. These are all abstruse subjects, involving concepts and language that are difficult even for those who have used them for years. But the barrier of specialized language that prevents most peple from entering into the living heart of modern scientific research can also be surmounted more readily. We can still use ordinary language to explain the basic concepts, and to make the vision of the world that science is in the process of advancing accessible to everyone.

In order to understand the origins of our universe, we must be prepared to undertake a risky journey. The danger comes from the fact that we need to push our minds into areas or environments so remote from those we are accustomed to that our usual conceptual categories are no longer of any use. We find ourselves obliged to say the unsayable, to depict the unimaginable, to experience the limits of our mind. Limits of a mind that for Homo sapiens has been a powerful tool for exploring and colonizing our planet, but which turns out to be altogether inadequate for fully understanding what happens in such vastly distant places. Like the explorers of old, we have no other option but to point the prow of the ship toward a horizon, and to accept the risks and the unknowns that go with navigating in uncharted waters.

Nevertheless, in scientific research the voyage home and return to port is also very important. In this respect the modern researcher is a lot like Ulysses, for wherever his journey takes him he is always dreaming of the moment when he will reach Ithaca again. Coming home also means, even if no new territory has been discovered, or we have suffered a terrible shipwreck, that it is possible to warn other sailors about the routes not worth taking, and the dangerous passages that should be avoided. We do this because modern science is also a great collective adventure. We have theories and charts to guide us, but chance often takes us to places that are completely unknown. We have “ships” that are meticulously cared for, but we only need to neglect one small detail and disaster can befall us. Our crew is a colorful and lively community of thousands of passionate minds, patient and curious modern explorers, quick like Ulysses to invent new stratagems to overcome whatever unexpected events might be thrown at them.

Despite the objectives of our research raising almost philosophical questions (“What is matter made of?” “How did the universe come into being?” “How will the world end?”), the practice of experimental physics is one of the most concrete activities imaginable.

A particle physicist—one of the thousands of researchers in the world exploring the behavior of the extremely small components of matter—does not spend his time sitting at a desk making calculations, meditating on theory, and fantasizing about new particles. A modern apparatus for high-energy physics is as tall as a five-story building, weighs as much as a cruise ship, and contains tens of millions of detectors. To construct and make operable these miracles of technology, thousands of people are required, and painstaking, obsessively detailed work that can take decades needs to be done. To devise new instruments more sophisticated than the previous ones, to prepare ships more agile and swift for our navigation, we spend years producing prototypes, in relentless efforts to make them work before going on to build them on a vast scale. And even when detectors are rigorously cared for and installed in the experiment, functioning quietly for months, we are always faced with the fear of catastrophe. An overlooked minor detail, a defective chip, a fragile connection, a cooling tube that has been hastily soldered can at any moment cause irreparable damage to the entire collective enterprise. The difference between an outstanding scientific success and the worst of all possible failures frequently lies hidden in some stupid, insignificant detail or other. 

How do we collect experimental information on the birth of space-time? How do scientists study the first cries of the infant universe? Two paths of knowledge come into play here, completely independent and different from each other. On the one hand, there is particle physics, exploring the infinitely small. Its starting point is the matter that surrounds us—what rocks and planets, flowers and stars are made sides, including ourselves. This matter has very special properties, which may appear ordinary to us, but that are in reality very peculiar in a way linked to the fact that the universe is a structure that is both very old and currently very cold. The most recent data tells us that our home was built almost 14 billion years ago, and that we are talking about an extremely cold environment, reaching what seem like impossibly freezing temperatures. For us, isolated on the planet Earth, everything seems comfortably warm; but as soon as we leave the protective shell of our atmosphere, the thermometer plunges. If we measure the temperature at any point in the vast empty spaces that separate stars, or in intergalactic space, the thermometer registers just a few degrees above absolute zero, which is to say minus 270 degrees Celsius. The matter of the current universe—rarefied, extremely ancient, and extremely cold—behaves in a very different way than when it was recently born and existed as an incandescent object of tremendously high density.

In order to understand what happened in those very first instants of life we need to be ingenious, to find a way of returning the elementary vestiges of current matter to the extremely high temperatures of those original conditions. We have to make a kind of journey back in time.

This is precisely what happens in particle accelerators. By making protons or electrons collide at very high energy, we exploit Einstein’s equation: energy equals mass times the speed of light squared. The higher the energy of the collision, the higher the local temperature that will be obtained and the greater the mass of particles that we are able to produce and study. To reach the maximum energies possible we need truly gigantic equipment, such as the Large Hadron Collider at CERN that stretches for some 27 kilometers beneath the ground near Geneva.

Here we find that by heating extremely small portions of space to temperatures comparable to those of the primeval universe, extinct particles revive: those ultramassive particles that used to populate it and that vanished eons ago. Thanks to the accelerators, they reemerge for an instant from their icy tomb, as if from hibernation, and may be scrutinized in great detail. This is how we discovered the Higgs boson. We brought back to life several handfuls after they had slumbered for 13.8 billion years. Naturally, of course, the much-sought-after bosons then immediately disintegrated into lighter particles, but they had left behind tell-tale traces in our detectors. The images of these special kinds of decay accumulated, and when the moment came when we were certain that the signal was well differentiated from the background, and that the other possible causes of error were under control, we announced the discovery to the world.

The exploration of the infinitesimally small, the reconstruction of extinct particles, the study of the exotic states of matter that everything was made up of at first—these constitute one of the two paths available for understanding the very first moment in the life of space-time. The other requires supertelescopes, huge instruments for exploring the infinitely large, and it studies stars, galaxies, and clusters of galaxies, in an attempt to encompass the entire universe. Here too we resort to Einstein’s equation in which the speed of light is fixed at approximately 300,000 kilometers per second: an extremely high but not infinite speed. Hence when we observe a very distant object, galaxies that are distant from us by billions of light years appear not as they are now (and it is quite difficult to define what “now” means), but as they were billions of years ago, when they actually emitted the light that has only just reached us.

Looking with supertelescopes at very large and very distant objects, it is possible to watch all the principal phases of the formation of the universe “live,” and to collect valuable data about our history. In this way, by observing the first faint signals emitted from the heart of enormous gas clouds, we can understand how stars are born: we observe the thickening of gas and dust in the rings of material that orbit around some new celestial body, indicating protoplanetary systems in formation. This is how our Sun was born.

But the most awe-inspiring thing of all is that these two paths of knowledge, based on methods so different from each other that they are almost entirely distinct—undertaken and developed by two wholly independent scientific communities—are nevertheless completely coherent with each other: the data gathered from the world of infinitely small elementary particles, and that which pertains to enormous cosmic distances, converge implacably towards the same story of origins.  --GT