Read The Day the World Discovered the Sun Online
Authors: Mark Anderson
An Extraordinary Story of Scientific Adventure and the Race to Track the Transit of Venus
Mark
Anderson
DA CAPO PRESS
A Member of the Perseus Books Group
Copyright © 2012 by Mark Kendall Anderson
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. For information, address Da Capo Press, 44 Farnsworth Street, 3rd Floor, Boston, MA 02110.
Designed by Timm Bryson
Set in 11.5 point Adobe Jenson Pro by The Perseus Books Group
Cataloging-in-Publication data for this book is available from the Library of Congress.
First Da Capo Press edition 2012
ISBN 978-0-306-82106-6 (e-book)
Published by Da Capo Press
A Member of the Perseus Books Group
Da Capo Press books are available at special discounts for bulk purchases in the U.S. by corporations, institutions, and other organizations. For more information, please contact the Special Markets Department at the Perseus Books Group, 2300 Chestnut Street, Suite 200, Philadelphia, PA 19103, or call (800) 810-4145, ext. 5000, or e-mail
[email protected]
.
10 9 8 7 6 5 4 3 2 1
For Penny
PROLOGUE
I closed my lids, and kept them close,
And the balls like pulses beat;
For the sky and the sea, and the sea and the sky
Lay like a load on my weary eye,
And the dead were at my feet.
âSAMUEL TAYLOR COLERIDGE
RIME OF THE ANCIENT MARINER
Oranges, bananas, pomegranates: how could such sweet fruit go so sour? Steady winds gusting off the Sea of Cortez did a fair job of keeping the flies from hovering over the dwindling piles of rotting food scattered around the huts and makeshift homes near the beach. But the flies had better places to lay their eggs. With every new day came a new crop of corpses.
Spanish frigate captain Salvador de Medina had spent nearly seven months escorting twenty-eight men across the Atlantic Ocean and the whole of Mexico to arrive at a former Jesuit sanctuary near the southern tip of the Baja peninsula. Medina had technically discharged his duty. But his orders included nothing about a deadly epidemic, a brutal and
unforgiving fever sweeping through the local population and filling graves by the hour. Medina knew the epidemic posed too great a threat to risk staying.
Yet, the man at the center of the expedition, the French astronomer Jean-Baptiste Chappe d'Auteroche, held his ground. Chappe, as he was known, had already begun to size up an abandoned corn barn at the former Jesuit mission inland. The barn would make a fine observatory, Chappe surmised. As if consumed by a fever of its own peculiar nature, Chappe refused to hear anything more about a port eighteen miles to the southwest. Word on the ground may have been that Cabo San Lucas was free of the contagion. But Chappe told Medina that he would not risk the expedition's founding purpose simply because of some rumor.
The group's late arrival on the white sandy shores of San José del Cabo the night before had left precious little time to spare before the afternoon sky would host a sensational spectacle.
The universe, Chappe liked to explain to anyone who would listen, would soon be opening itself up for a rare inspection. Although anyone without a telescope would never notice it, for five and a half hours on June 3, 1769, a little dot would appear to cross the disk of the sun. That little dot was the planet Venus. Its shadow crawled across the sun's face, at most, only twice per century. Timing the planet's entire transit down to the second and comparing other observations of the same event from elsewhere on the globe, Chappe said, would by year's end enable humankind to discover something that had evaded it since the dawn of timeâthe exact physical dimensions of the sun and its planets and the distances that separated them. Venus's transit opened a brief window into the very architecture of God's creation.
This, Chappe explained, is why no mere disease could be allowed to interrupt his careful observations of the practically theological phenomenon that a fortnight later would be taking place overhead.
Having spent his first night ashore sleeping on the beach, Chappe mustered what remained of the able-bodied natives. Two leagues inland
stood the mission that would serve as Chappe's observatory. Much work remained to be done, and with very little time to spare. The first job entailed hauling Chappe's delicate telescope and other scientific equipment inlandâprecision instruments whose every fragile inch had endured muttered curses of Spanish soldiers porting them nearly halfway across the world from ship to jungle and back to ship again.
The observatory's one widely recognizable instrument looked like the guts of a clock quartered and served up like a piece of pie. A kind of maritime priesthood wielded the quadrant with incantations and scriptures that were as mysterious as Holy Writ to most of the sailors.
A ship's navigator typically used this machine and a table of nautical charts to measure the moon and sun and sometimes stars. Through a mathematical ritual that occupied the navigator for hours on end, these measurements would then produce a crucial number that everyone at sea could appreciate: longitude.
Longitude was the most costly puzzle of its time. And astronomy was poised to solve it. Esteemed astronomers like Chappe commanded authority with royal audiences and military commanders. Commanders like Medina.
The groans of wretched men and glimpses of the cadavers they became underscored how dire the situation had become. Still, as the morning's sweat turned clammy from cooler breezes that nudged the mule train inland, Medina and Chappe remained tense allies bound by death's encroaching shadow.
Theirs was a world inching closer to discovering great secrets behind the sky. But the sun shone down relentlessly, and it forgave no one unprepared. The sun would have its day.
Reddened hands fastened the barge to its mooring. For the past month the Danube's breezes had chilled its travelers. No more. A brisk walk from the canal bank, and Viennaâwith its famously narrow streets, tall buildings, and fragrant coffeehousesâwelcomed its visitors in from the cold.
Just eight years before he would travel to San José del Cabo, French astronomer Jean-Baptiste Chappe d'Auteroche and his party made a wintry landing in the capital city of the Habsburg monarchy and, with it, much of the Holy Roman Empire. His was a journey altogether of its time. The turbulent 1760sâwhen the Enlightenment was in full bloom but before bloody revolutions had brought the age's heady ideals down to earthâwould effectively frame the world's most concerted effort to find the sun.
In transit from Paris, Chappe and his servantsâas well as “M. Durieul,” a Polish military man traveling to Warsawâoffloaded their Danube barge and walked through the city gates of Vienna. The crunching snow underfoot and clouds of condensed breath had become familiar
companions as Chappe's party daily pressed eastward. Still, the Viennese chill could not compare to the core-consuming freeze Chappe and his servants were about to undergo. Their ultimate destination was Tobolsk, a remote town in Siberia.
In April, Chappe's colleague, the seventy-two-year-old astronomer Joseph-Nicolas Delisle, had presented a paper to the Académie Royale des Sciences in Paris arguing that Tobolsk was one of the best locations on earth to observe the coming transit of Venus on June 6, 1761. The
Mappemonde
that Delisle presented the French academy served as a sort of global menu of the most coveted destinations that teams of explorers and scientists across Europe would be risking their lives to venture to.
June 6 was the first time in living memory that the skies provided such a rare opportunity to plumb the solar system's size. Venus had last transited the sun 122 years previously in 1639, more than a generation before mathematicians had figured out the trick that enabled the sun's distance to be triangulated. Venus would provide one more chance on June 3, 1769. After that, another 105 years would elapse before Venus again passed in front of the sun.
The 1761 transit, as these scientists (known then as natural philosophersâphilosophes) told their country's paymasters, presented the best opportunity in more than a century to get a precise fix on the sun's distance. And thanks to the planetary laws discovered by Johannes Kepler in the seventeenth century, knowing the distance to the sun allowed scientists to locate the orbital path of every planet. One measurement unrolled the blueprint to “the heavens and the earth”âwhat the biblical book of Genesis said God created at the universe's very beginning. It was arguably as close to knowing the mind of the Creator as anyone had yet conceived. “If we make the best use of [the Venus transits],” the instrument maker and popular science author Benjamin Martin wrote in 1761, “there is no doubt but that astronomy will, in ten years time, attain to its ultimate perfection.”
1