An Exercise in Perspective
If you're not familiar with the HubbleSite, you should be. The official website of the Hubble Space Telescope is rich with scientific background, news releases and announcements of new discoveries, and of course, jaw-dropping imagery of the cosmos, taken by one of humanity's most justifiably famous scientific instruments.
One of Hubble's newest images has left me feeling inspired, and I'd like to say a few words about it. But first, the picture itself:
This stunningly gorgeous image is a view of the spiral galaxy M81, one of the so-called "grand design" spiral galaxies due to its intricate and sharply delineated structure. In Hubble's view, the spiral arms of the galaxy are clearly visible, a vast whirlpool of stars, nebulae and interstellar dust revolving around the galactic core. M81 is about 12 million light-years from Earth, in the direction of the constellation Ursa Major, and is one of the brightest galaxies that can be seen from our planet (although it is just slightly too faint to view with the unaided eye, though easily seen with a telescope). M81 has lent its name to the cluster of galaxies in which it can be found, the M81 Cluster, sister to the Local Group of galaxies that contains our own Milky Way. Both the M81 Cluster and the Local Group, in turn, are part of the larger Virgo Supercluster, a group of galaxies spanning 150 million light-years.
M81 is similar in many ways to our own Milky Way. The galaxy's central disk contains relatively older, cooler reddish stars, while the spiral arms are home to hot, young blue stars, created by the rotation that sends waves of gas and dust sweeping across the galaxy like ripples in a pond, triggering bursts of star formation. At the center of M81, unseen, lurks a monster: a black hole with the mass of 70 million suns, sending out jets of radiation as raw starstuff swirling into its maw is churned and heated by the acceleration. Though the black hole itself swallows light and thus is invisible, in ultraviolet imagery we can see the white-hot accretion disk surrounding it, the last cry of matter falling into the abyss and out of our space-time continuum. (The Milky Way, too, has a central black hole, though ours has consumed all the gas and dust in its vicinity and has therefore become quiescent.)
Look again at that striking Hubble image. As beautiful as this picture is, I don't mind admitting that I feel a tremor of fear when I view it, especially at the larger resolutions. I feel this way because I know what that image represents: something so breathtakingly vast - something cosmic, in the truest sense of the word - that it beggars the imagination and overwhelms the ability of the mind to truly conceptualize it. Before the intricacy and scale of even a single galaxy, all of humanity and in truth the Earth itself is reduced to infinitesimal size, infinite insignificance. Compared to M81 or the Milky Way as a whole, we are not even a glimmer, not even a speck of dust. The cosmic forces that operate on the very largest of scales utterly determine our fate, beyond the ability of any person to resist or escape, and yet they are utterly incognizant of us. We could be brushed out of existence by them tomorrow, and in the grand scheme of things, the universe would never know that we had even existed. That, I think, is awe in the truest sense of the word: to stand before that which is so much greater than the self, and know yourself to be humbled by comparison.
Now, I'd like to propose an exercise in perspective. We inhabitants of Earth are embedded within the Milky Way, and cannot see it from outside. But if we could travel the staggering distance required to view our galaxy from the outside, from intergalactic space, it would probably look very much as M81 does.
Imagine, therefore, that this picture is of the Milky Way. In that case, our own sun, our solar system, our tiny and humble Earth would be located on the outer fringes, in one of the galaxy's spiral arms. On an image of the scale of this one, of course, they would be utterly invisible. This picture contains billions and billions of suns, and from this distance they are not distinguishable as individuals. Their light blends together into a hazy, glowing cloud, occasionally swirled through with dark lanes of dust. On the scale of this image, our mighty Sun would dwindle to a dust speck, just one of the thousands of stars whose light contributes to each pixel on your screen. The Earth itself, a tiny pale blue dot next to the Sun, would be as a dust speck to a dust speck. And humanity and all our mighty works, a thin, fragile skim of life on the surface of our world, would be even less altogether.
Consider the cosmos from this perspective, and then ask yourself: Do you believe that all of this was made just for us?
On our world today, there are still representatives of ancient religions who hold that the entire vast universe was created solely for man and placed under our governance - that the natural laws that apply on every scale across the cosmos and govern the origin and future evolution of billions of galaxies and trillions of stars were fine-tuned for humanity's benefit - that our tiny planet is the only place God cares about, the only place he is interested in - and that on our judgment day, all the stars and all the galaxies will be rolled together as a scroll and will cease to exist.
The presumption, the sheer arrogance of this belief boggles the mind. It would make as much sense for a single atom within your body, if atoms were conscious, to declare its dominion over you and assert that you exist only as a vessel for the drama of its individual salvation. Some other believers, though they do not go so far as this, still assert that the laws of nature single out humans as special, treating us as different from everything else that exists.
We are such a small, such an infinitesimal part of the cosmos as to utterly destroy any ridiculous claims that it was all crafted for our benefit. Next to even one galaxy, we are less than nothing. And M81 is not all there is, but rather only one galaxy among billions, one tiny part of a tableau so grand that even magnificent spirals like this one shrink to insignificance in comparison. When we peer deeply into space, we see a fractal-like scene, with even the tiniest possible patch of the night sky turning out to contain thousands of galaxies. The hierarchy of scale runs beyond anything we can visualize or comprehend. How could anyone believe that it was all put here for our sake?
When we were young, we looked up at the twinkling lights in the night sky and wondered. Most of them were immovable, fixed stars rising and setting in the same place every night as if pinned to the dome of the firmament. However, a very few of those lights were not so steady. Instead, they seemed to meander, moving perceptibly across the sky from night to night - sometimes even changing course and moving backwards for a time, as if in a spirit of play. We named these vagabond stars planets, after the Greek word planetes, which literally means "wanderer".
For many long centuries, the nature of these wanderers was unknown to us. Our wise theologians advised us that they were no more than lights affixed to nested crystal spheres that rotated around us, placed as signs and portents so that we could marvel at the power of the cosmic Designer who framed them. Even the moon, closest to our own earth, was an orb of mystery whose ever-changing faces became synonymous with the unsettling and the strange.
But then we discovered how to grind glass to focus light, and distant rays streaming into our retinas brought illumination: the planets are not mere lights after all. They are places, whole worlds of their own, both like and unlike the Earth. They have mountains and valleys, craters and river channels, deserts and ice caps, and spectacular night skies of their own with rings, satellites, and one other wandering, blue star. It is true, our species has walked on the moon; we have taken our first tentative steps into that vast cosmic ocean that surrounds us. But there are other vistas that await us. Far from our humble yet beautiful world, there are other shores upon which no human being has ever set foot.
Yet where we have not traveled, our emissaries have gone before us: bright-eyed creatures with limbs of silver and gold, seeing into subtle bands of the spectrum we can only imagine. They hurtle unscathed through the vacuum of space, tireless through the long journey, until at last they reach their destination: an oasis appearing out of the void, a distant twinkle of light that swells into a vast new world. In obedience to the faint voices from their place of origin, our heralds swing into orbit around these distant shores, or descend to their surfaces. And there they have found magnificent beauty - landscapes of gorgeous desolation, of primordial power, of grand intricacy; landscapes that tell stories of an ancient history, a history that passed countless eons unregarded and unknown - until now. And what our messengers see, they report back to their makers.
At right is a magnificent image of Saturn, from high above the ringed planet's north pole, taken on January 19 by the Cassini spacecraft now in orbit around that world. This is a natural-color view: if a human being was in this orbit, they would see the same image that Cassini saw. So fantastically perfect as to be almost unreal, Saturn sits half in sunlight and half in darkness, casting a vast shadow across the plane of its majestic rings. Stark and geometric in its clarity, the image makes it almost too easy to forget that this is not a mere model, but a vast world of its own, a gas giant larger than hundreds of Earths. Only Cassini's celestial perspective, like a god looking down from on high - this picture was taken from a distance of three-quarters of a million miles - renders Saturn's alien beauty as comprehensible as it is.
The Cassini mission has glimpsed other wonders as well. It took seven years of travel through the void for the probe to reach Saturn - a stark reminder of how enormous the distances are that separate us from even the nearest fellow worlds - but there were chances to survey other shores along the way.
At left is a true-color mosaic of the planet Jupiter, taken in December 2000. The gas giant is a world of clouds, banded with swirls of weather in intricate patterns of turbulence, wreathing and diffusing like smoke in air or colorful ink in a glass of milk. In the southern hemisphere, the vast cyclonic storm system called the Great Red Spot continues to roil and churn the atmosphere, as it has been doing since it was first observed by the astronomer Giovanni Cassini, in whose honor the current mission is named, in the 1600s.
When it comes to the truly cosmic, it is all but impossible for a limited human being to grasp the sense of scale. However, it may help to see how large the Earth is in comparison. In comparison to regal Jupiter, all the distant lands and mighty seas where Earth's most famous explorers dared to venture are but a ripple in an unimaginably more enormous ocean of atmosphere. Though Jupiter has no solid surface on which to tread, a traveler who could soar through its upper reaches could spend a thousand human lifetimes and never see more than a tiny fraction of the stunning vistas that must surely await there.
Above: An image of Titan from Cassini. Dense clouds hide the planet's surface.
But Jupiter and Saturn, for all their grandeur and their beauty, were not the Cassini probe's only destinations. The ringed planet has a moon, named Titan - a world of unfathomable mystery, one that may even hold the keys to understanding the origin of life on our own blue planet.
Titan is the only moon in the solar system with a substantial atmosphere, one that is actually denser than Earth's. But a dense orange haze clouds Titan's atmosphere and hides its surface from view, and until recently we had no idea what lay beneath the clouds. There have been tantalizing hints. Based on spectroscopic observations and laboratory experiments similar to the famous Miller-Urey experiment, the late Carl Sagan concluded that Titan's haze might be made of a muddy mixture of organic compounds called tholins - possible building blocks of life - that were constantly raining down on the moon's surface like manna falling from heaven.
It has long been conjectured that lakes of liquid methane and ethane might exist on Titan's frigid surface, and that these hydrocarbon lakes could be the source of the Titanian tholins. Evaporating and rising into the atmosphere, these simple compounds would be broken down by ultraviolet radiation from the Sun, recombining into the more complex organic molecules that shroud the surface in haze. But this idea is mere speculation no longer. Cassini's radar can pierce the clouds of Titan, and several weeks ago, it returned this false-color image of dark, smooth patches of liquid on the moon's rough surface - the long-hypothesized hydrocarbon lakes, glimpsed at last.
But we have done more than just examine Titan from orbit. The Cassini spacecraft carried a lander, Huygens, which parachuted down to the moon's surface to report back on what it found. Here is one of the images it returned, a true example of an almost unimaginably distant shore:
Above: An image of Mars taken by Viking 1. In the foreground, the vast Valles Marineris canyon system slices across the surface of the planet.
Not every shore we visit is as exotic as ringed Saturn or cloud-shrouded Titan. Our planetary neighbor Mars, compared to these strange and distant worlds, is practically a close friend, and we know it with familiarity befitting that designation. Both on the surface and from orbit, our robotic servants have mapped and explored Mars, peeling back the eons of its history, and uncovering stunning evidence of its past. Too small for its gravity to hold an atmosphere as dense as our own, Mars is now a dry, freezing desert, with an ethereally thin atmosphere and regular planet-wide dust storms. But we now know that it once had a warm, clement past complete with liquid running water, the prerequisite for all life as we know it. Astonishingly, Mars' polar ice caps contain enough water to flood the entire planet to a depth of over thirty feet, and its surface bears signs of past reworking by water on a colossal scale. And though we have not yet found evidence of life on Mars, neither have we ruled out the possibility that it may still exist beneath the planet's rusty soil.
Below is an image of the striking Martian surface feature known as Victoria Crater, the half-mile-wide scar of some ancient impact, taken from space by the Mars Reconnaissance Orbiter:
And here is an image of Victoria Crater's rim from the surface, courtesy of the robotic rover Opportunity that is now exploring it:
Opportunity's twin, Spirit, has not been slumbering either. Here is Spirit's current view, the McMurdo Panorama, a landscape of desolation that nevertheless seems strikingly Earthlike:
Despite its loneliness, Mars can present scenes of astonishing beauty. On occasion, Spirit has even had the chance to pause from its scientific work and simply admire a sunset, so familiar and yet so strange, such as this one taken at Gusev Crater from April 2005:
Images like this are a much-needed reminder that the Earth is not the only place in the cosmos. Though the Earth is all we know, and sometimes this leads us to myopically imagine it is all there is, there is a whole universe of landscapes awaiting us. Our solar system alone contains a multitude of gorgeous and fantastic scenes which no human was ever privileged to see - until now.
In a very real sense, everyone alive today is an explorer on a scale more profound than the seafarers of bygone ages ever conceived of. Not with our bodies, but with our eyes and minds we have traveled forth to begin exploration of the cosmos. Images like this should teach us a valuable lesson in humility, a reminder that we are not the center of the universe. Yet at the same time, they should rightfully fill us with awe and wonder. There are wholly new worlds awaiting our study, places stranger and yet more beautiful than we could have imagined. How can such a revelation not fill us with joy?
(All images in this post courtesy of NASA/JPL-Caltech.)
All Days Are Holy
The word "holiday" comes directly from the phrase "holy day". This designation, in turn, is based on the curious notion that a particular event happening on a certain date forever afterward gives that date some special sacredness or magical quality. The day of Halloween, for example, was once believed to be a time when barriers between our world and the other world grew thin and restless spirits could return to haunt the land of the living, and other supernatural events are often tied to the Christmas season.
But if a holiday is really a holy day, then what does that mean for the rest of our calendar? Are other days not holy? Are we to believe that God is somehow more present or more accessible on those days than on other days?
This is just one example of the irrationality of some theists who claim to believe that God is omnipresent, yet act as if certain places, times, or objects were more imbued with his presence than others. Another well-known example is the macabre trade in "relics", which thrived during the Middle Ages and continues to attract much attention even today: belief that the personal possessions or even the body parts of a dead saint or holy man possess some type of supernatural power. Even today, shrines containing relics of saints are major destinations of pilgrimage, and there are stores (such as this one) that sell items such as bottled water from the Jordan River or soil from supposedly sacred sites in Israel. Even the Bible endorses this bizarre belief in magic, such as in an Old Testament passage where a dead man is resurrected by coming in contact with the bones of the prophet Elisha (2 Kings 13:21).
If I were inclined to believe in such a being as God, I would think it obvious that no day, no place, no item could be any more or less holy than any other. It surely follows from the standard theistic beliefs that if God created everything in the cosmos, then everything is equally his handiwork and imbued with his spirit. Faith, likewise, is a quality displayed by a person's actions; it cannot somehow contaminate inanimate objects with which that person comes in contact, nor could it linger in a body after the vitality has gone. All such beliefs are extensions of the human tendency toward reification - thinking of abstract ideas and qualities as if they were material things with independent existence.
If there is any meaningful sense in which an atheist can use the word "holy", then it must surely be true that all days are equally holy in that sense. We believe in no divinities, no relics, no elusive magical quality of sacredness. Instead we treat our holidays not as literal holy days, but as occasions to remember events of particular significance in our past that led to the state of affairs as we see it today. If our memories were perfect, we would need no holidays at all; but humans are imperfect, memories fade, and marking a particular date can serve as a good reminder of some event or achievement that deserves not to be forgotten due to the important lessons it still has to teach us.
But in the magical sense, in the moral sense, to an atheist all days are holy. On every day, there are heartbreaking sunrises and beautiful sunsets; on every day, there are people coming together to do good for each other; on every day, there are crimes, tragedies, and pains. No day is set apart, no day is sanctified, no day is any more or less spiritual or sacred than any other. Every day presents us with the same opportunities to act, whether for good or for evil, and to make choices that will influence the subsequent direction of our lives.
A Tribute to Carl Sagan
Between the excitement of the midterm elections and the flood of atheism-related news that has occurred this month, there was one very important date that passed almost unnoticed, but that I would be remiss if I failed to mention. Namely, November 9 was the birthday of the famous astronomer and skeptic Carl Sagan. If he were still alive, he would have been 72 this month.
Sagan's scientific achievements were groundbreaking and hardly need me to recount them. During a time when the human species was taking its first tentative steps out into the solar system, he indisputably led the way. He was one of the primary scientific advisors on some of the earliest unmanned missions to study the planets, including the Pioneer, Viking and Voyager missions, and was the chief architect of the Voyager Golden Record that contains the images and music of our civilization, in case any extraterrestrial intelligence should happen to recover the probe millions of years in the future. He was one of the first scientists to hypothesize that Venus was boiling hot due to a runaway greenhouse effect, that Jupiter's moon Europa contains subsurface oceans beneath a layer of ice, and that a haze of organic molecules rains from the sky on Saturn's moon Titan, all of which turned out to be correct. He was also a well-known advocate of SETI, the Search for Extraterrestrial Intelligence, and one of the trailblazing advocates who turned it into a respectable area of scientific research in its own right.
But despite his considerable scientific achievements, Carl Sagan is best remembered as a popularizer who brought the wonder and awe of science and the importance of skepticism to the public. That this aspect of his career often outshines his prolific scientific work is a measure of just how good he was at it. He was the author or co-author of many books eloquently expressing the romance and power of scientific discovery, including Broca's Brain, The Dragons of Eden, Pale Blue Dot, The Demon-Haunted World, Billions and Billions, and Shadows of Forgotten Ancestors, many of which are still personal favorites of mine. But the best-known of all his roles was as the host of Cosmos, an award-winning PBS television series and accompanying book whose grand sweep travels from humanity's ancient past to the glorious diversity of life to the universe on the very largest of scales, and ends with an eloquent plea for peace and reason in the face of all the threats, mostly self-caused, that confront us. Cosmos is still the most widely viewed science documentary in the history of humanity; it is estimated that over half a billion people have seen it worldwide. I cannot think of a more worthy candidate for such an honor.
As my readers are probably aware, Carl Sagan's life was cut tragically short. I will let this great man tell the story in his own words, in an excerpt from the last chapter of his final book, Billions and Billions:
...one morning late in 1994, Annie [Sagan's wife, Ann Druyan] noticed an ugly black-and-blue mark on my arm that had been there for many weeks. "Why hasn't it gone away?" she asked. So at her insistence I somewhat reluctantly (black-and-blue marks can't be serious, can they?) went to the doctor to have some routine blood tests.
We heard from him a few days later when we were in Austin, Texas. He was troubled. There clearly was some lab mixup. The analysis showed the blood of a very sick person. "Please," he urged, "get retested right away." I did. There had been no mistake.
Sagan had become ill with myelodysplasia, a rare and deadly form of leukemia. The only hope for survival was a bone marrow transplant, and by a stroke of good fortune, his younger sister Cari matched in all six genetic compatibility factors that would be needed for a successful one. Sagan went through several grueling rounds of chemotherapy, radiation and transplants, but the disease recurred, a few malignant cells escaping each round of treatment to kindle a new flare-up. In the end, it seems, he triumphed over myelodysplasia; but the treatment had taken a terrible toll, and his weakened immune system could not fend off a bout of pneumonia that wracked his lungs and, ultimately, ended his life. Ann Druyan was at his side as he died, and wrote in the epilogue to Billions and Billions:
Contrary to the fantasies of the fundamentalists, there was no deathbed conversion, no last minute refuge taken in a comforting vision of a heaven or an afterlife. For Carl, what mattered most was what was true, not merely what would make us feel better. Even at this moment when anyone would be forgiven for turning away the reality of our situation, Carl was unflinching.
...For days and nights Sasha [his daughter] and I had taken turns whispering into Carl's ear. Sasha told him how much she loved him and all the ways that she would find in her life to honor him. "Brave man, wonderful life," I said to him over and over. "Well done. With pride and joy in our love, I let you go. Without fear. June 1. June 1. For keeps..."
The rawness of these words, written so soon after Sagan's death, still stings my eyes even as I type this. The world is a slightly darker place without him, and though he has now been deceased almost ten years, I am often reminded of how much need we still have of him. His passing preceded, by only a few years, my discovery of his writings and my enthrallment by them. It is one of my few regrets that I never had the chance to write him a letter to let him know how much his work meant to me.
But more so, I regret knowing that he had the terrible misfortune to die before seeing so many of the wonderful discoveries humanity has made in the ten years since, many of which can be credited to his legacy. There is the Stardust mission that flew through the dusty corona of the comet Wild-2 and became the first spacecraft to return comet dust to Earth; the Wilkinson Microwave Anisotropy Probe that has revealed the most detailed picture ever taken of the cosmic microwave background radiation, conclusively determining the age and large-scale structure of the universe; the Cassini-Huygens mission to Saturn and its moons, including a lander that parachuted onto the surface of Titan itself; and the robot rovers Spirit and Opportunity, which even now are exploring Mars and uncovering astonishing evidence that, though the planet is now a freezing dry desert, it had a warm, wet, Earthlike past. Such discoveries would undoubtedly have brought Sagan much joy. I am sorrowful that he missed them, for he more than anyone else deserved to live to see them; but I find some small comfort in knowing that they at least were made, and that there are many more people eager to join the pursuit of scientific progress, some of whom were perhaps inspired to do so by Sagan himself, who will continue to raise the banner of discovery and raise our eyes to the awe and wonder of living in the cosmos.
Though many new brilliant and eloquent scientific popularizers have emerged over the past ten years, none of them match up to Carl Sagan. I mean no insult by saying so, and I trust none will be perceived. If, as the man himself said, science is a candle in the dark, then Carl Sagan's candle burned brilliantly against that dark, glowing like a miniature sun. In that light was an eloquent hope of all that humanity could become, and a poignant reminder of how much we have in common and how insignificant the things that divide us truly are. Though we can never replace him, we can do the next best thing and carry forward the ideals he defended so powerfully. Rest in peace, Dr. Sagan. We will remember, and you have my word that we will not allow your candle to go out.
Cathedral of Suns: A Humanist Sermon
In my encounters with religious proselytizers, I have occasionally been told that atheism robs the world of the sense of awe and wonder, that my lack of belief in a god who miraculously created us all must mean that my life is lacking in the intangible qualities that makes it worth living. I have been told, as well, that I reject the possibility of a god too great for me to understand. This is my reply to those claims.
There is a famous photograph taken by the Hubble Space Telescope of a region called M16, also known as the Eagle Nebula, that lies 7,000 light-years from Earth in the direction of the constellation Serpens. It is more colloquially called the "Pillars of Creation". The Hubble image depicts three tall, twisted, intricately shaped clouds of gas and dust, like columns of smoke rising from a campfire. At the tips of each of these columns are dozens of tiny fingerlike protrusions, very small by comparison, easily overlooked among the eerie beauty of the entire scene. It is only when you understand what you are really looking at that the scale of this image becomes apparent. Those minuscule protrusions are new stars being born. Each of them is far larger than our entire solar system. The Eagle Nebula is a stellar nursery, where new suns are coalescing from interstellar clouds of molecular hydrogen – a place where the attractive pull of gravity causes the denser clouds to collapse on themselves, becoming denser and hotter until their cores reach the multimillion-degree temperatures required to ignite nuclear fusion, synthesizing hydrogen into helium. The outward pressure of the energy released by this reaction counterbalances the inward pull of gravity, causing the new star to enter a stable state in which it can shine for millions of years, until its fuel is exhausted.
But even the Eagle Nebula is only a very small part of our own galaxy. On a clear, dark night far from the lights of civilization, you can see the Milky Way itself, a faint, misty band of light that arches across the night sky. But again, the sight only attains its full degree of awe when you understand what you are looking at. Using parallax and luminosity measurements, we have mapped the Milky Way, our own galaxy, and found it to be a barred spiral of a hundred billion suns, so large it takes light a hundred thousand years to cross from one end to the other. Our solar system is on the outer edge of the galaxy, embedded in one of its rotating spiral arms. When you see that faint band of light, you are looking inward, toward the center of the galaxy, where the light from millions and millions of stars blurs together into a glittering cloud. If certain hypotheses in astrobiology are correct, some of those distant stars may harbor advanced civilizations of their own, fellow travelers in this vast and uncharted cosmos that we have yet to discover.
But our gazes have ventured even beyond the Milky Way itself. We have realized that some of the fuzzy patches in the night sky are not stars or nebulae, but other galaxies, magnificent island universes spread out like jewels against the ocean of universal dark. But our universe is not a peaceful place. Through our telescopes, we see cosmic catastrophes on a scale too vast to comprehend. In some of these distant galaxies, we see supernovae – the cataclysmic deaths of stars, explosions so bright that they briefly outshine the entire galaxy in which they occur. At the center of many galaxies, we see cosmic monsters, massive black holes with the mass of millions of suns that devour streams of matter and send out intense jets of radio and X-ray energy. We see galaxies themselves collide, their gravitational tides tearing each other apart. And on rare occasions, we have seen explosions even more enormous than supernovae, called gamma-ray bursts, some of which are so bright that they briefly outshine the entire rest of the visible universe. Gamma-ray bursts inevitably occur at cosmological distances, billions of light-years from Earth, and their exact cause is still unknown. Perhaps most incredibly of all, when we read the light from these galaxies, we see that every single one of them, save for a few in our local cosmic neighborhood, is shifted towards the red, indicating that they are hurtling away from us. They are receding from us, and we from them, as space itself expands.
We have mapped the distribution of galaxies on the largest scales and found that it is not entirely random. Viewed from outside, our universe would resemble a foam of soap bubbles, with structures called "great walls" – vast sheets made up of thousands and thousands of galaxies – wrapped around even more enormous voids. One of the most famous large-scale surveys of galaxy distribution revealed a figure astronomers named the "Stickman" – a supercluster of galaxies spread across the northern sky, 500 million light-years wide, in a shape that vaguely resembles a stick-figure drawing of a human being.
Beyond even this, we have seen the very first light in the universe. We have studied the sky in microwave light and glimpsed the afterglow of the Big Bang – a diffuse bath of energy that pervades the entire cosmos, the fading remnants of the initial white-hot fireball, now cooled to about three degrees above absolute zero by time and expansion. We have found tiny temperature variations in this cosmic microwave background radiation – fluctuations of millionths of a degree, observed by a satellite named WMAP that even now orbits at the second Lagrangian point, almost a million miles from Earth, in the darkness of space. These almost imperceptible temperature ripples date back to the instant of origin; they represent spots of slightly increased or decreased density, tiny departures from uniformity at the very beginning, that seeded all the future formation of stars and galaxies. They are the blueprint for the universe as it exists now, 13.7 billion years later.
The point of all this is that, by following the scientific method, we have discovered a cosmos far vaster, more intricate, more magnificent, more awe-inspiring, and to which we are more deeply and fundamentally connected than any poet or theologian of antiquity ever dreamed of. All the elements in our bodies heavier than hydrogen – the carbon of our cells, the oxygen we breathe, the iron in our blood, the calcium in our bones – were synthesized from lighter nuclei in the cores of massive stars and blown into space when those stars died, becoming dispersed throughout the cosmos and enriching nebulae that formed the next generation of stars, including the one out of which our solar system formed about five billion years ago. When you look into the night sky, you are viewing the place where you came from. We are all, quite literally, stardust, heirs to a lineage that dates back to the Big Bang itself. Even the greatest thinkers of the prescientific era never conceived of something so amazing. Even they never imagined a universe as grand and majestic as the one we now know we actually live in.
Then I turn to the Book of Genesis, and what do I read? I read that God made the Earth, his green footstool, with loving care and painstaking effort and attention to fine details during the first three days of creation, before anything else existed. Then, and only then, on the fourth day, he creates the entire rest of the universe – everything I have just described, all the majesty, all the immensity – as background, as scenery, as a tossed-off afterthought, for no reason other than to serve as signs and portents to the inhabitants of the Earth.
In fact, it's not just the Bible – it's all religions. All of them reflect the prideful fantasy that human beings are central to the workings of the universe. None of them ever anticipated all the incredible things we have discovered. When theists tell me that I am putting God in too narrow a box, I reply that their belief does not give him nearly enough credit.
These religions myopically imagine that this pale blue dot, this green atom, this place that is an infinitesimal speck inside an infinitesimal speck when compared to the unimaginably awesome vastness of the cosmos, is not just a place of interest to the creator of it all, not even just the most important place, but the very reason for the creation to exist at all and the only thing in it that has any real meaning or interest to God. We look out into the sky and see crashing galaxies and exploding stars and black holes that consume suns, and religion says that the death of a single man or the formation of a small fiefdom thousands of years ago is the most important thing that ever happened in the history of the universe. We witness planet-sized storm systems in the atmospheres of gas giants, explosions visible across the whole of the known universe, and ultradense, collapsed remnants of suns called neutron stars, so dense a teaspoonful of their matter would weigh millions of tons and rotating hundreds of times per second - and religion tells us that a minor shift to the course of one waterway on our planet, or the collapse of one ancient city's mud-brick walls, is a great miracle. Can an atheist be blamed for thinking that this theology reflects nothing but the arrogant anthropocentrism of the humans who came up with it? Can we be blamed for thinking that it is so small because its creators were small?
Though I do not believe there actually is a deity who created all this, if there was one, I would expect that he would be large enough to fit the creation. Part of the reason I am an atheist is that, based on the facts I observe, I have tried to reason my way to a conclusion about what a god who made the universe would look like, and the answer I keep getting is not in accord with what any current religion says. And though I would freely accept that I was wrong if I could see evidence otherwise, such as a clear communication from God, I have received nothing like that.
In any case, lacking theistic belief does not in any way impair an atheist's ability to feel awe and wonder, or to recognize that there are things far greater than us. If anything, I believe this cathedral of suns, infinitely vaster and more majestic than anything made by hands, produces a sense of awe and wonder so far surpassing the imaginings of religion that it clearly shows all of them to be untrue. The cramped and antiquated imaginations of human beings do not compare to the true glory and grandeur of the cosmos as it really is.
Richard Feynman's blackboard at Caltech at the time of his death in 1988. The text in the lower left reads, "Know how to solve every problem that has been solved." From Stephen Hawking, The Universe in a Nutshell, p. 83.
Since I was very young, I have been fascinated by the findings of science. It really is true that the world is a more intricate and wonderful place than we can imagine, and even the limited glimpses we have obtained into its underlying workings are more than enough to provoke awe and wonder of the most sublime kind. The more causes we understand, the more connections we perceive, the more incredible a place we see the world to be. Every peak we climb, through long and diligent effort, opens the way to a new and even greater vista before us.
I do not know when, or whether, the growth of our understanding will ever stop, but I am determined to follow it as long as I can, to appreciate as much as I am able. What is my goal in all of this? What do I want to know? The answer is simple: I want to know everything.
I want to be aware of everything that is happening, every new discovery that is being made.
I want to speak every language.
I want to know all of human history and understand the manifold and intricate reasons that guide its unrolling from one event to the next - the trajectory of every bullet, the spark of every idea, the vibration of every spoken word.
I want to know how Homo sapiens became the thinking species, who first tamed fire, invented the wheel, chipped stone to make a tool.
I want to peer back in history and see the human genome evolving, to watch the spirals of DNA twist and coil in the throes of natural selection, dispatching new instructions on how to build the body.
I want to know how the mind works, how signals crackling from one neuron to the next give rise to consciousness.
I want to see in geological time, so that I can watch civilizations rise and fall, glaciers advance and retreat, forests grow and fade, mountains spring up and erode down to nothing, continents glide across the earth on molten conveyors. I want to see populations migrate and shimmer in the thrall of mutability, where endless forms most beautiful emerge from the old in an endless flux of variation, radiation and extinction. I want to see the tree of life, perceive its many countless branchings, and comprehend the kinship we share with all living things.
I want to know how life started on Earth, in whatever warm pool or pitted stone or hydrothermal vent the first molecules drifted together, attracted each other, and clung together to become the first fragile self-replicators, delicate as gossamer at first, but then spreading out from their birthplace in an exponential wave to cover the entire planet.
I want to know how the planet itself formed, to see the swirls in the primordial nebula, see the collapse beginning, see the heart of the cloud brighten and ignite with solar fire, see the chunks of dust and stone that accreted, the collisions that baptized the new worlds in flame; to see the formation of the continents, the cooling and condensing of their oceans.
I want to perceive every scale, from the subatomic particles that tremble and flicker, to the magnificent galaxies that spin and collide, to the very largest distance scales where galaxies themselves are mere atoms in the structures that span the universe.
I want to comprehend the entire cosmos, from the quantum ripples in the initial white-hot fire to the chill of its ultimate end, and see it all as a whole. I want to see the fourth dimension of time like the other three, hanging above and watching people and planets trace spiraling paths through space-time, the history of the cosmos laid out in full view in one seamless whole.
I want to comprehend all the causal links. When I see an event happen, I want to know everything that affected it, everything that influenced it, all the subtle and intricate saliencies; I want to know the entire grand weave of causality, so that its outcome is as familiar and expected to me as the motions of my own body. I want to see the numbers and equations in everything.
To know everything is, of course, an utterly unattainable goal, something I am all too aware of. A person could spend their entire life in study of one small aspect of the world and still not grasp even that in its totality, and the connections between different areas are so numerous and intricate that sometimes it seems one would already to have to know everything to know everything else. We are disentangling them, one painstaking step at a time, though I do not expect this grand effort to be finished or even close to finished in my lifetime. Nevertheless, I am content to follow as best as I am able, and learn as much as I can. To echo Isaac Newton's words, I may never swim in the vast ocean of truth, but there is still beauty and wonder in the pebbles and shells we may find along the shore.