Alternative Histories of the Sun, Moon, Planets, and Stars
Publication Year: 2005
These and other imaginative scenarios are the subject of Arthur Upgren's inventive book Many Skies: Alternative Histories of the Sun, Moon, Planets, and Stars. Although the night sky as we know it seems eternal and inevitable, Upgren reminds us that, just as easily, it could have been very different.
Had the solar sytem happened to be in the midst of a star cluster, we might have many more bright stars in the sky. Yet had it been located beyond the edge of the Milky Way galaxy, we might have no stars at all. If Venus or Mars had a moon as large as ours, we would be able to view it easily with the unaided eye. Given these or other alternative skies, what might Ptolemy or Copernicus have concluded about the center of the solar sytem and the Sun?
This book not only examines the changes in science that these alternative solar, stellar, and galactic arrangements would have brought, it also explores the different theologies, astrologies, and methods of tracking time that would have developed to reflect them. Our perception of our surroundings, the number of gods we worship, the symbols we use in art and literature, even the way we form nations and empires are all closely tied to our particular (and accidental) placement in the universe.
Many Skies, however, is not merely a fanciful play on what might have been. Upgren also explores the actual ways that human interferences such as light pollution are changing the night sky. Our atmosphere, he warns, will appear very different if we have belt of debris circling the globe and blotting out the stars, as will happen if advertisers one day pollute space with brilliant satellites displaying their products.
From fanciful to foreboding, the scenarios in Many Skies will both delight and inspire reflection, reminding us that ours is but one of many worldviews based on our experience of a universe that is as much a product of accident as it is of intention.
Published by: Rutgers University Press
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TO BART BOK ...
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Blessed is he who learns how to engage in inquiry, ...
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The sky we see is a familiar one, with few changes taking place over thecourse of a single human lifetime. Our current view results from a del-icate balance between many factors, and changes in just a few of themwould have given us a sky with a very different appearance. For ex-ample, what if we had more than one sun in the sky? Or more than one...
Part I. The Sun and the Moon
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Chapter 1. Our Three Moons
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Our Moon, our eternal companion, our queen of the night, was the result of an accident. The Earth has been accompanied by its faithfulmoon almost since the formation of the solar system 4.6 billion yearsthose early days of the system than there is now; planet-sized chunksnot ready to settle down into final, proper nearly round orbits revolv-...
Chapter 2. Within a Triple Star
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We assume here that the Sun is one of three stars in a system thatclosely resembles Alpha Centauri. We can still refer to it as the solarsystem, since our Sun is the largest, closest, and brightest of the lot. Ata distance of only 4 light years, Alpha Centauri, seen in the deep south-ern sky as a single star, is the nearest of all stars and the third brightest...
Chapter 3. Our Backward Stellar Magnitude System
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The stellar magnitude system was developed, as far as anyone knows,by Hipparchus in the second century B.C. He produced a catalogue ofthe thousand brightest stars visible from his home city of Alexandria.Then he divided the stars into five classes of brightness, in which thefirst magnitude was reserved for about twenty of the brightest stars....
Chapter 4. An Improper Proper Motion
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With the magnitude scale now explained in Chapter 3, we return to theProxima, also known as Alpha Centauri C, is one of the tiniest starsin nearby space, truly a 10-watt bulb among stars. It circles the paircomposed of Helios and Osiris and their planets at a distance of some13,000 astronomical units, about one-fifth of a light year. Its orbital pe-...
Chapter 5. All Our Yesterdays
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The tower stands foursquare to the ocean and the wind. It is the pride of thecity and the Empire. The city, Alexandria, the second largest in the RomanEmpire after Rome itself, stretches for miles along the juncture between oneof the mouths of the Nile River delta and the seacoast. It is an importantgranary and supply depot for lands surrounding the entire Mediterranean...
Chapter 6. We Are Alone
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The Sun was setting on that bleak November day. In another hour the skywould be dark. On overcast nights we could see a modicum of light fromnatural and artificial illumination from the ground, but on clear nights theworld and the sky are totally dark. No moons or planets act to illuminatethe night because none exist. Only the stars remain. On occasion the Au-...
Part II. The Planets
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Chapter 7. The Rings of Earth
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October always brings on the frigid days, the days when the Sun proceedssouth to the point where it passes behind our great celestial ring system.The average daily temperature has dropped by 10 degrees just this weekand we must get out our winter wear. Then in early November, the warmthreturns, at least for a while. Like Saturn, we have this giant ring system...
Chapter 8. Next Door to a Giant
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What a sight the Moon and nearby Jupiter make when they appear close toeach other in the evening sky before and after sunset. The Moon subtendsan angle of half a degree, 3 times that of Jupiter, if that huge planet were inthe orbit occupied by Venus, or about 10 times the area in angular terms.Balanced against this is the fact that the big planet, perpetually enshrouded...
Chapter 9. Double Planet
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I looked upon the Martian surface. From a slight rise I could look straightalong one of the “canals” that covered the planet when an intelligent racewas assumed to have mounted a great effort to irrigate the equatorial re-gions from the melting polar caps during each hemisphere’s springtime.The Sun shone along the canal low in the deep southwestern sky; it would...
Chapter 10. Debris in the Solar System
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Halley’s comet is the only bright, spectacular comet that has a period of less than a few thousand years. What if its period were not about 76 years but only 5 or 10? Many comets move about that quickly, withEncke’s comet orbiting in only 3.3 years, the briefest of all. But, like themajority of comets, none of these are visible to the naked eye. They...
Chapter 11. Seasons of Paradox
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The Sun moves along the ecliptic by definition; it is the Sun’s pathtraced out in the sky. Since the ecliptic is inclined 231⁄2H11034 from the celes-tial equator, over the year the Sun moves no closer than 90H11034H11002231⁄2H11034H11005661⁄2H11034 from either celestial pole. It does so in June when it is nearest thenorth celestial pole and again in December when closest to the south...
Chapter 12. More than One Pluto
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Is Pluto a planet or is it something less? For years this question has beenPluto’s 1930 discovery stemmed from the observations that neitherUranus nor Neptune followed the orbits that Newton’s cosmos, evenwith Einstein’s alterations, derived for them. Uranus strayed from theorbit it should have complied with, and this led directly to Neptune’s...
Part III. The Stars.
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Chapter 13. What if the Sun Were Red? Or Blue?
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Stars come in an assortment of colors. Not just any old color, as crayonsdo, but in the colors of the spectrum or rainbow. In Chapter 2, we notedthat as stars get hotter they proceed in tint from red through orange,yellow, and white to blue. There are instances in the past in which ob-servers have described the colors of some individual stars as mauve,...
Chapter 14. The Vernal Equinox Lies in Vergo
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The sky changes slowly. With an occasional exception, alterationsamong the stars and constellations are orderly and require centuries formajor changes to be detected. The supernovae that appeared in 1572and 1604, known as Tycho’s Nova and Kepler’s Nova, were and wouldbe today totally unanticipated. But the other changes, the motions of...
Chapter 15. Vega and Deneb Change Places
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The summer triangle consists of three bright stars in three differentconstellations; they dominate the zenith area in the sky all summerlong, and with Arcturus to the west and Antares in the deep south, theyare the brightest stars visible at the time. All three are blue, with Vegaeasily the brightest at magnitude 0.0, while Altair and Deneb, at 0.8 and...
Chapter 16. The Pleiades Star Cluster is as Close as the Hyades
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Stars are frequently bunched together into clusters; a cluster consists of stars gravitationally bound together, moving with a common paral-lel motion, and presumed to share a common origin. Clusters come in three different flavors, open clusters, globular clusters, and associa-tions, with associations sometimes grouped together with the more...
Chapter 17. The Great Popcorn Balls
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The southern end of the city and island of Miami Beach, known as SouthBeach, occupies the southern tip of that municipality and island. SouthBeach has graduated from a region of modest housing for older middle classpeople to an upscale neighborhood for swinging singles and others. Aftersunset, with palm trees swaying and clicking in the breeze in the balmy twi-...
Chapter 18. The Milky Way Lies Along Our Equator
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Coordinate systems are devised to identify uniquely each and everypoint on a surface. They typically fix points on a plane, a left-right mea-sure commonly labeled the x-coordinate and an up-down scale knownas the y-coordinate. These kinds of systems are called rectangular or,more commonly, Cartesian coordinate systems, named after René Des-...
Chapter 19. We Are Alone II
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Ours is not the only galaxy; there are many others, billions altogether,scattered throughout the visible universe. Three of the nearest amongthem have been mentioned above; two of these are the Large and SmallMagellanic Clouds, the two small satellite galaxies to our own MilkyWay, about 180,000 light years from us. The third is the great spiral...
Part IV. Homemade Skies
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Chapter 20. Ring of Rubbish
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Artificial satellites have been with us since October 1957, when the So-viet Union launched the first Sputnik, almost half a century ago now.Since that time satellites have become more numerous and sophisti-cated, but in one respect they have not changed. This is their visibility,their luminance from reflected sunlight as they spin about the world....
Chapter 21. The Tangled Skein of Celestial Mechanics
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Celestial mechanics, the science of the determination and prediction ofthe positions of celestial objects, began with Johannes Kepler. He wasthe first to draw conclusions directly from observations—in his casethose of Tycho Brahe. Kepler published his three laws of planetary mo-tion, the first two in 1609 and the third ten years later. The first law, ...
Chaper 22. A Second Chance
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The landscape was still with only the wind breaking the stony silence. Thelake lay quiet and blue, not a restful blue but intense, of a piece with thesurrounding desert, gray-white and rocky, not sandy such as Arab horse-men might ride over in Saharan melodramas like Sigmund Romberg’sDesert Song. Directly in front stood a stone house, now clearly abandoned....
Chapter 23. Chicxulub, The Worst Sky of All
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Earlier today we felt the ground shake, a great shudder of such violencethat trees swayed back and forth and a few lost limbs or even fell over.Then nothing—all was quiet. But moments afterward great fireballsswooped across the sky, so bright that they could not only be seen infull daylight, but were even bright enough to cast shadows almost as in-...
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Three of the illustrations in this book are taken from paintings by ChesleyBonestell (1888 –1986). Bonestell was the premier illustrator of imaginedscenes on other worlds. Two of the three paintings, shown in Chapter 7, il-lustrate Saturn and its glorious system of rings, and the third, in Chapter 17,depicts a globular cluster in very close proximity to the Earth. It is a plea-...
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About the Author
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Arthur Upgren, Ph.D., is Emeritus Professor of Astronomy at WesleyanUniversity and Senior Research Scientist at Yale University. He haswritten three previous books and many research articles in his field. Heis active in reducing light pollution and restoring the night sky to its...
Page Count: 216
Publication Year: 2005