An Intimate Look at the Night Sky

by Raymo, Chet

• ISBN13: 9780802776709
• ISBN10: 0802776701
• Edition: Reprint
• Format: Paperback
• Copyright: 2003-04-01
• Publisher: Walker Books

Summary

On one level,An Intimate Look at the Night Skyis a unique star guide: twenty-four beautiful star maps, created specifically for this book, cycle through the seasons and across the heavens, revealing what you can see with the naked eye throughout the year on a clear night in the northern hemisphere. Raymo's commentaries amplify the maps, offering intriguing details and tips on identifying stars, planets, and constellations. On another level, Chet Raymo challenges our imaginationto see what is unseeable in the universe, to perceive distance and size and shape that is inconceivable, to appreciate ever more fully our extraordinary place in the cosmos. His elegant essays on the heavens blend science and history, mythology and religion, making clear why he is one of the most insightful and passionate science writers of our time.

Author Biography

For nearly forty years, Chet Raymo has been exploring the relationship between science, nature, and the humanities as a professor, writer, illustrator and naturalist. In The Path: A One-Mile Walk Through the Universe, he uses the one-mile path he has walked to work for the past four decades as a means of discovering the extraordinary in everyday life.

A professor emeritus of astronomy and physics at Stonehill College in North Easton, Massachusetts, Raymo is the noted author of more than eight books on science, including the highly-praised An Intimate Look at the Night Sky, 365 Starry Nights, The Soul of the Night, Honey from Stone, and Skeptics and True Believers. In 1998, he won a prestigious Lannan Literary Award for the body of his non-fiction work. Raymo is also the author of two novels, In the Falcon's Claw (1990) and The Dork of Cork (1993), which has been sold in twelve languages.

Since 1985, he has written "Science Musings" for the Boston Globe , a weekly science and nature column reflecting upon the human side of science. He is also a frequent contributor to popular science and nature publications.

Chet Raymo and his wife Maureen live in North Easton, Massachusetts.

Table of Contents

Acknowledgments	vii
Introduction	ix
I. Winter
Star Maps: Orion, Canis Major, Canis Minor	2	(4)
Alpha: In the Beginning	6	(16)
Star Maps: Taurus, the Pleiades, Auriga	18	(4)
Dark: Why the Night Is Dark	22	(18)
Star Maps: Gemini, Cancer	36	(4)
Far: The Distances to the Stars	40	(18)
II. Spring
Star Maps: Leo, Virgo	54	(4)
Fusion: How Stars Burn	58	(18)
Star Maps: Ursa Major, Ursa Minor	72	(4)
Spin: The Planets	76	(18)
Star Maps: Bootes, Corona Borealis, Hercules	90	(4)
Swoosh: Comets and Meteors	94	(20)
III. Summer
Star Maps: Libra, Scorpius, Sagittarius	110	(4)
Shadow: The Moon and Eclipses	114	(18)
Star Maps: Lyra, Cygnus, Aquila, Sagitta, Delphinus	128	(4)
Death: How Stars Die	132	(18)
Star Maps: Capricornus, Aquarius, Fomalhaut	146	(4)
Vortex: The Milky Way Galaxy	150	(18)
IV. Autumn
Star Maps: Cassiopeia, Cepheus, Pegasus	164	(4)
Myriad: The Universe of Galaxies	168	(16)
Star Maps: Andromeda, Perseus	180	(4)
Spirit: Life in the Universe	184	(18)
Star Maps: Pisces, Aries	198	(4)
Omega: How the Universe Will End	202	(15)
Appendix 1. Planets	217	(5)
Appendix 2. Meteor Showers	222	(1)
Glossary	223	(4)
Resources	227	(2)
Information About the Photographs	229	(4)
Index	233

Excerpts

Chapter One

ALPHA

In the Beginning

Here is a way to experience the stars as you never have before--and to come as close as you will ever get to the first moment of creation.

    Take yourself as far as possible from city lights, to a place where the night is inky black and thick with stars. If you can, turn off all local lights. Make sure the Moon is not in the sky, or at least no more than a slender crescent. A winter or summer night is best, when the Milky Way arches high overhead and the sky is posted with brilliant stars. Two other requirements: solitude and silence. You'll also want an audio CD player and a recording of Joseph Haydn's The Creation oratorio. Lie back comfortably on a deck chair or a blanket, facing up to the stars. Place your finger on the "play" button, and close your eyes. Wait a few moments until you are perfectly relaxed, then, with your eyes still closed , push "play."

    Silence. A C-minor chord, somber, out of nowhere. Followed by fragments of music. Clarinet. Oboe. A trumpet note. A stroke of timpani. A prelude of shadowy notes and thrusting chords, by which Haydn meant to represent the darkness and chaos that preceded the creation of the world. Listen now, eyes closed, as the music descends into hushed silence. Hear the voice of the archangel Raphael: "In the beginning God created the heaven and the earth, and the earth was without form and void, and darkness was upon the face of the deep." The chorus, subdued, barely audible, sings: "And the spirit of God moved upon the face of the waters; and God said: Let there be light!" Then, the voices whispering, once and only once: "And there was light." Open your eyes! A brilliant fortissimo C-major chord! A sunburst of sound. Radiant. Dispelling darkness. A universe blazes into existence, arching from horizon to horizon. Stars. Planets. The luminous river of the Milky Way. As you open your eyes to Haydn's fortissimo chord and to the (almost) forgotten glory of a truly dark starry night, you will feel that you have been a witness to the big bang.

    A modern astronomer would recognize in Haydn's music a breathtaking analogue to our contemporary theory of creation. According to our present story, the universe began 15 billion years ago from an infinitely small, infinitely hot seed of energy--what mathematicians call a singularity . The singularity was not "somewhere"--The fabric of space-time came into existence with the explosion. There was no "before," at least none that we can presently know. Space swelled from the singularity like a balloon inflating from nothing. Time began. During the first trillion-trillion-trillionth of a second, matter and antimatter flickered in and out of existence. The fate of the universe hung precariously in the balance; it might grow, or it might collapse back into nothingness. Suddenly it ballooned to enormous size (after all, we are here), in what cosmologists call the inflationary epoch, bringing the first particles of matter--the quarks--into existence. Within one-millionth of a second, the rapid swelling ceased, and the quarks began to combine into protons, neutrons and electrons.

    The universe continued to expand and cool, but now at a more stately pace. Already it was vastly larger than what we are able to observe today. Within a few more minutes, protons and neutrons combined to form the first atomic nuclei--hydrogen and helium--but still the universe was too hot for the nuclei to snag electrons and make atoms. Not until 300,000 years after the beginning did the first atoms appear. Tiny density variations in the gassy universe of hydrogen and helium were accentuated by gravity, which pulled together the first stars, gassy planets, and galaxies. There were not yet any solid-surface Earth-like planets, because there were not yet significant quantities of ,elements heavier than hydrogen and helium, such as carbon, oxygen, silicon, and iron. (These elements would be cooked up latert in the cores of massive stars and distributed to space when stars died explosively at the end of their lives.) Still, within a billion years of the big band, the universe had begun to look familiar on the largest scale.

    Try to imagine all of this as Haydn's music continues. A bright and lilting melody takes up the story. Musical themes coalesce from chaos. Disorder falls away. The mood changes from somber to gay, and the chorus sings a dancelike tune: "A new-created world springs up at God's command." The chorus repeats the phrase again and again, as if it is not a single world that God creates, but a multitude of galaxies and stars. The bass intones, "And God made the firmament." Music leaps and dances into thrilling passages of sound. "By sudden fire the sky is inflam'd," the bass sings. Thunder rolls from the orchestra. Sixteenth notes fill the air as multitudinous as the stars that silver-fleck your dome of night. This stunning consonance between Haydn's music and the universe above your head is no coincidence.

    On a visit to England in 1782, Haydn sought out the astronomer William Herschel, world famous as the discoverer of the planet Uranus. Herschel was himself a transplanted German and a musician, an organist and music teacher who became the most prolific astronomer of the eighteenth century. He had moved to England with his sister Caroline (who would also become an accomplished astronomer) in 1772, and four years later he had constructed the six-inch diameter reflecting telescope with which he found Uranus, the first addition to the five planets known to the ancients. Not only did the discovery of this planet attract the attention of Haydn; it also won Herschel financial support from King George III, which enabled him to become a full-time astronomer, and to construct in 1788 a forty-eight-inch diameter reflector that remained the largest telescope in the world for half a century.

    A view of deep space through Herschel's instrument may have inspired Haydn's musical depiction of God's work on the Fourth Day, the creation of the Sun, Moon, and stars. Certainly Haydn admired the astronomer's giant telescope and may have listened to Herschel's ideas about how gravity condensed the cosmos out of chaos. It was Herschel who first supplied evidence (by plotting the locations of thousands of stars in three dimensions) that the Milky Way is a disk-shaped array of millions of stars (today we would say hundreds of billions), and he guessed that many of the nebulous patches of light visible in his telescope were other Milky Ways, other vast swarms of stars--what the philosopher Immanuel Kant had called island universes . After a visit to the astronomer in 1786, the novelist Fanny Burney exclaimed that Herschel "has discovered fifteen hundred universes," an extraordinary bit of gush that was not far off the mark. Later, Herschel would back away from the idea of island universes, but not before he had imagined a universe of galaxies and guessed the shape of our own spiral galaxy, which he compared to a "grindstone."

    The orchestra ascends now on a crescendo of luminous sound. "In splendor bright is rising now the sun," the tenor sings. "The space immense of th' azure sky, a countless host of radiant orbs adorns." As you lie beneath the ink-dark night with its thousands of visible stars, imagine the countless other stars that Herschel saw through his giant instrument. Also, imagine the host of nebulae that he observed and cataloged, invisible to the unaided eye (although, if it is summer, you might just see a faint glow in the constellation Andromeda that is the central region of the nearest spiral galaxy to our own). Imagine, as you lie beneath the stars listening to the remainder of Haydn's composition, that this multitude of worlds--expanded by modern telescopes to include hundreds of billions of galaxies--was brought into being by that whispered evocation "And there was light," that singular, explosive C-major chord that accompanied the opening of your eyes. Wonder, too, that the big bang universe of galaxies resides within your consciousness. Haydn's Creation oratorio and Herschel's universe of galaxies have become our own, and not even the mystery of the creation itself rivals the greater mystery of how, through the instrumentality of human art and science, the universe has come to know itself.

There is one significant difference between Haydn's libretto, which is based upon Judaic scriptures, and the modern astronomer's story of creation: The explosive chord that follows Haydn's "And there was light"--his musical big bang--has a prelude , those minutes of shadowy and slightly discordant sounds that represent the darkness and chaos that preceded "the beginning." The big bang of the astronomers has no prelude, at least none that we can know. The universe begins as a singularity--a mathematical infinity that poses an impenetrable barrier to knowing what came before. There are a few speculative cosmologists who try to tease from their equations some glimpse of what might have preceded the creation of the universe 15 billion years ago--perhaps a frothing foam of universes that bubble in and out of existence like the effervescence of champagne--but all of this must for the time being be considered science fiction. For all practical purposes, the big bang had no "before."

    Nevertheless, many striking similarities remain between the creation described musically by Haydn and the astronomer's big bang. These similarities may represent prescient insights on the part of Haydn and the authors of Genesis. More likely they represent conceptual limitations of the human brain. There are only so many ways a universe can be imagined coming into existence. Myth, art, and science work from the same limited repertoire of metaphors. Haydn's universal architect speaks, and there is light. For the modern astronomer, space and time begin as a fiery explosion from an infinitely small, infinitely dense seed of energy: the big bang. The seed has no human face, but it bears the lineaments of human creativity.

    The concept of the big bang had its genesis in a single startling discovery, made in the 1920s, with a big new telescope on Mount Wilson in California. The instrument had a mirror more than twice the diameter of Hershel's largest instrument, and it showed something that Herschel had not been able to see: Many of Herschel's blurry nebulae were composed of vast swarms of individual stars. They were in fact other "island universes," as Herschel had guessed--other Milky Ways of hundreds of billions of Suns, in the shapes of balls, ellipsoids, and, most spectacularly, pinwheel spirals. We now call these star swarms galaxies, from the Greek word galaktos , "milk." Because astronomers could now see individual stars in the nebulae, it was possible to estimate their distance from their apparent brightness. The distances turned out to be staggeringly great. The nearest of the spiral nebulae, the one we see with the naked-eye as a blur of light in Andromeda, is 2 million light-years away! None of this was terribly surprising to the astronomers; after all, Herschel had guessed as much more than a century earlier. The big surprise was something different, something discovered by the astronomers Edwin Hubble and Milton Humason: The galaxies are racing away from us, or, more accurately, racing away from one another. The universe of the galaxies is expanding!

    And if the galaxies are moving apart, then they must have been closer together in the past. Theoretically, we can run the movie backward, using the laws of physics to tell us what happens. The galaxies converge. The density of matter increases. The temperature soars. Atoms dissolve into their constituent parts. Mass evaporates into pure energy. Run the movie 15 billion years into the past, and the whole thing--the entire universe of galaxies that exists today--collapses into an infinitely small, infinitely dense, infinitely hot mathematical point. The singularity. The progenitor of the big bang.

    How do we know that running the movie backward gives a true picture of the beginning? We do experiments here on Earth with high-energy particle-accelerating machines to figure out how matter behaves at extremely high temperatures. Using this knowledge, we calculate what sort of universe should have emerged from the big bang. Then we compare the calculated universe to the universe we observe with our telescopes. So far the fit is excellent. Two modern observations in particular confirm our confidence in the big bang. Theory predicts that when ordinary matter first condensed from the hot particle soup of the big bang it should have consisted almost entirely of hydrogen and helium in a ratio of about three to one, and that's exactly the ratio of these elements that we find in the universe today. Also, the theory predicts that if we look far enough out into space, and therefore far enough back into time, we should see the flash of the Big Bang as a blaze of luminosity that has subsequently cooled into invisible microwave radiation. This prediction is in exact agreement with observations made with a space telescope called Cosmic Background Explorer (COBE).

    As I write this, physicists at the Brookhaven National Laboratory on Long Island are cranking up the temperature of their experiments higher than ever before--to one trillion degrees! They will hurl heavy atomic nuclei in opposite directions around a powerful $600-million accelerating machine--the Relativistic Heavy Ion Collider--until the nuclei are moving at nearly the speed of light, and then smash them into one another. Out of these titanic nuclear collisions, which last only the tiniest fraction of a second, they hope to see emerge a new kind of matter--a quark-gluon plasma --the presumed super-hot primordial broth out of which all ordinary particles were born. No one has seen a naked quark before, or the gluons that supposedly bind the quarks into protons, neutrons, and electrons; they have not existed since the earliest instants of creation. If these new experiments are successful, and the quarks and gluons show themselves, physicists will catch a glimpse of what the universe might have been like in its first millionth of a second, before protons, neutrons, and electrons came into existence. Then they can run the theoretical movie backward even farther into the past and compare the calculated universe and the observed universe with yet more exactitude.

    No one could have been more surprised by a big bang beginning than the twentieth-century astronomers themselves. Creation from nothing was not a story they favored. For cultural reasons--perhaps a reaction against the scriptural scenario or the intractability of that mathematical singularity--they preferred the tranquil poise of a universe that had existed forever. They expected no boundaries when they looked out into the universe with their telescopes, no infinities that could not be conceptually climbed, only space and time stretching on and on into the past and future without limit. In 1915, Albert Einstein glimpsed the possibility of a beginning as he played with the equations of his new theory of general relativity; his equations predicted a universe that must expand or contract. But Einstein was so repelled by what he saw--a singular moment of beginning or a catastrophic end--that he added a fudge factor to his theory to make the universe settle down into tractable serenity. He would later say that it was the biggest mistake he ever made, for not long thereafter the astronomers on Mount Wilson showed him his error.

    It is a grand adventure, this search for origins. It is what drew Haydn to Herschel's observatory and inspired the composer's magnificent Creation oratorio, whose libretto was drawn from the Judaic scriptures. Scientists of today are doing no more than did the authors of Genesis thousands of years ago: They are inventing stories of the beginning. Unlike the makers of myth, today's storytellers have evolved rigorous experiments and observations to test their inventions in the refining fire of experience.

(Continues...)

Copyright © 2001 Chet Raymo. All rights reserved.