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® Br ca ti anni LEARNING L I B R A R Y Science and Nature Uncover the mystery of everyday marvels, from rocks to rainbows CHICAGO LONDON NEW DELHI PARIS SEOUL SYDNEY TAIPEI TOKYO PROJECT TEAM Judith West, Editorial Project Manager Christopher Eaton, Editor and Educational Consultant Kathryn Harper, U.K. Editorial Consultant Marilyn L. Barton, Senior Production Coordinator Editors Theodore Pappas Anthony L. Green Mary Rose McCudden Andrea R. Field Michael J. Anderson Colin Murphy Locke Petersheim Indu Ramchandani (Encyclopædia Britannica India) Bhavana Nair (India) Rashi Jain (India) Design and Media Specialists Nancy Donohue Canfield, Design Megan Newton-Abrams, Design Karen Koblik, Photos Joseph Taylor, Illustrations Amy Ning, Illustrations Jerry A. Kraus, Illustrations Michael Nutter, Maps Copy Editors Barbara Whitney Laura R. Gabler Dennis Skord Lisa Braucher, Data Editor Paul Cranmer, Indexer ENCYCLOPÆDIA BRITANNICA PROJECT SUPPORT TEAM EDITORIAL Linda Berris Robert Curley Brian Duignan Kathleen Kuiper Kenneth Pletcher Jeffrey Wallenfeldt Anita Wolff Charles Cegielski Mark Domke Michael Frassetto James Hennelly Sherman Hollar Michael R. Hynes Sandra Langeneckert Gene O. Larson Michael I. Levy Robert Lewis Tom Michael Janet Moredock DESIGN Steven N. Kapusta Carol A. Gaines Cate Nichols ART Kathy Nakamura Kristine A. Strom Nadia C. Venegas ILLUSTRATION David Alexovich Christine McCabe Thomas Spanos MEDIA ASSET MANAGEMENT Jeannine Deubel Kimberly L. Cleary Kurt Heintz Quanah Humphreys COPY Sylvia Wallace Jennifer F. Gierat Glenn Jenne Mary Kasprzak Thad King Larry Kowalski Joan Lackowski Dawn McHugh Julian Ronning Chrystal Schmit Sarah Waterman INFORMATION MANAGEMENT/ INDEXING Carmen-Maria Hetrea Edward Paul Moragne Marco Sampaolo Sheila Vasich Mansur G. Abdullah Keith DeWeese Catherine Keich Stephen Seddon EDITORIAL TECHNOLOGIES Steven Bosco Gavin Chiu Bruce Walters Mark Wiechec COMPOSITION TECHNOLOGY Mel Stagner MANUFACTURING Dennis Flaherty Kim Gerber INTERNATIONAL BUSINESS Leah Mansoor Isabella Saccà ENCYCLOPÆDIA BRITANNICA, INC. Jacob E. Safra, Chairman of the Board Jorge Aguilar-Cauz, President Michael Ross, Senior Vice President, Corporate Development Dale H. Hoiberg, Senior Vice President and Editor Marsha Mackenzie, Managing Editor and Director of Production © 2008 BY ENCYCLOPÆDIA BRITANNICA, INC. Cover photos (front): © Lester Lefkowitz/Corbis; (back): © Corbis. Cover insert photos (left): © Jeff Vanuga/Corbis; (right): © George B. Diebold/Corbis International Standard Book Number: 978-1-59339-504-9 No part of this work may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. BRITANNICA LEARNING LIBRARY: SCIENCE AND NATURE 2008 Britannica.com may be accessed on the Internet at http://www.britannica.com. (Trademark Reg. U.S. Pat. Off.) Printed in U.S.A. Science and Nature I N T R O D U C T I O N What are tsunamis? Why did the dinosaurs disappear? Why do some leaves turn red? What woman won two Nobel Prizes in the sciences? Science and Nature, you’ll In To help you on your journey, we’ve provided the following guideposts in Science and Nature : ■ Subject Tabs—The colored box in the upper corner of each right-hand discover answers to page will quickly tell you the article subject. these questions and many ■ Search Lights—Try these mini-quizzes before and after you read the more. Through pictures, article and see how much—and how quickly—you can learn. You can even articles, and fun facts, you’ll learn about weather, meet fascinating make this a game with a reading partner. (Answers are upside down at the bottom of one of the pages.) ■ Did You Know?—Check out these fun facts about the article subject. With these surprising “factoids,” you can entertain your friends, impress scientists, and see how your teachers, and amaze your parents. plants and animals can ■ Picture Captions—Read the captions that go with the photos. They change over time. provide useful information about the article subject. ■ Vocabulary—New or difficult words are in bold type. You’ll find them explained in the Glossary at the end of the book. ■ Learn More!—Follow these pointers to related articles in the book. These articles are listed in the Table of Contents and appear on the Subject Tabs. Br ® ca itanni LEARNING L I B R A R Y Have a great trip! © 2008 Encyclopædia Britannica, Inc. A fallen maple leaf shows its autumn colors. © Royalty-Free/Corbis © 2008 Encyclopædia Britannica, Inc. Science and Nature TABLE OF CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 SOME ESSENTIALS GEOLOGY: Studying the Earth . . . . . . . . . . 34 Atoms: Building Blocks of Matter. . . . . . . . . . . . . . . . 6 The Earth’s Building Blocks . . . . . . . . . . . . . . . . . 36 Rocks and Minerals: Chalk: The Remains of Tiny Shells . . . . . . . . . . . . . 38 Liquids, Solids, and Gases: Sand: The Nitty-Gritty . . . . . . . . . . . . . . . . . . . . . . . 40 Same Stuff, Different Forms . . . . . . . . . . . . . . . . . . 8 Diamonds: Echoes: Sounds That See in the Dark . . . . . . . . . . . 10 Energy: The Power of Life . . . . . . . . . . . . . . . . . . . . 12 The Hardest-Working Gemstones in the World . . . 42 Leaves: The Science of Their Changing Colors . . . . . 14 Volcanoes: Mountains of Smoke and Fire . . . . . . . . . 44 Fossils: Ancient Life in Stone . . . . . . . . . . . . . . . . . 46 PHENOMENA OF NATURE Dinosaurs: Giants of the Past . . . . . . . . . . . . . . . . . 48 Temperatures: Hot and Cold. . . . . . . . . . . . . . . . . . . 16 Dinosaurs: A Mystery Disappearance . . . . . . . . . . . . 50 Dew: Diamond Drops of Water . . . . . . . . . . . . . . . . . 18 Tyrannosaur: The Tyrant King. . . . . . . . . . . . . . . . . 52 Clouds: Floating Water. . . . . . . . . . . . . . . . . . . . . . . 20 Mammoths and Mastodons: Ancient Elephants . . . . 54 Rainbows: Arcs of Color. . . . . . . . . . . . . . . . . . . . . . 22 Thunder and Lightning: Nature’s Fireworks . . . . . . 24 NATURE SCIENTISTS Cyclones and Tornadoes: Nature’s Fury . . . . . . . . . . 26 Luther Burbank: Inventing New Plants . . . . . . . . . . 56 Acid Rain: Killer Downpour . . . . . . . . . . . . . . . . . . . 28 Marie Curie: Discovering a New Kind of Science. . . . 58 Waves: Movement on the Seas . . . . . . . . . . . . . . . . . 30 Charles Darwin: The Theory of Evolution . . . . . . . . . 60 Tsunamis: Waves of Destruction . . . . . . . . . . . . . . . 32 GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Br ® ca itanni LEARNING L I B R A R Y © 2008 Encyclopædia Britannica, Inc. Buf iMladtting Blocks o er E verything in the world is made up of molecules. Our bodies, our clothes, our houses, animals, plants, air, water, sky—everything. Molecules are so small, though, that we can’t see them with our naked eyes. But molecules aren’t the smallest things. Molecules are made up of atoms, which are smaller still. Atoms are so small that it takes more than a billion atoms to fill the space taken up by one pea! The word “atom” comes from the Greek word atomos, meaning “indivisible.” But despite what their name suggests, atoms can indeed be divided into smaller pieces. Each atom has a core called a “nucleus.” Around the nucleus swarm small particles called “electrons.” The nucleus itself is made up of other small particles called “protons” and “neutrons.” And these protons and neutrons are made up of even smaller things called “quarks.” So, for now at least, quarks are among the smallest known things in the universe. LEARN MORE! READ THESE ARTICLES… ENERGY • LIQUIDS, SOLIDS, AND GASES • MARIE CURIE ? KNOW U ntists O Y s t a th cie scribe DID so small de re w ways to Quarks a ke up ne the different a m to e hav r bout ocolate o ey talk a them. Th f quarks—not ch harm,” o “c “flavors” t “up,” “down,” u b om.” pistachio “top,” and “bott ,” “strange © 2008 Encyclopædia Britannica, Inc. © 2008 Encyclopædia Britannica, Inc. ★ 7 Answer: FALSE. Atoms can be split into electrons, neutrons, and protons, all of which are smaller than the atom itself. And quarks are even smaller than those. True or false? Atoms are the smallest things of all. SE A
T GH RCH LI ATOMS s m r o F t n e , f f Same Stu Dif fer D id you know that many of the things you may see or use every day—such as the water in a glass, the air in a football, and even the hard metal in a toy car—are potential shape-shifters? The substances that these things are made of can have the form of a solid, a liquid, or a gas. The form they take depends mostly on their temperature. When water gets cold enough, it becomes a hard solid we call “ice.” When it gets hot enough, it becomes a wispy gas we call “steam.” Many other substances behave the same way when they are heated or cooled enough. A solid holds its own size and shape without needing a container. If you pour water into an ice tray and freeze it, the water will keep the shape of the cube-shaped molds in the tray. You can think of the solid metal in a toy car as frozen too, but its melting temperature is much higher than the temperatures we live in. The person who made the car poured very hot liquid metal into a car-shaped mold and let it cool down and freeze. A liquid does not hold its own shape. If you pour a measuring cup of water into a tall glass or a shallow bowl, it will take the shape of its container. But that water does keep its own size. It measures one cup. Everyday liquids such as milk, paint, and gasoline act this same way. Gases do not keep their own shape or their own size. When air is pumped into a football, it takes the shape and size of the ball. As more air is pumped in, the ball gets harder but not much bigger. The air changes its size to fit the space inside the ball. LEARN MORE! READ THESE ARTICLES… ENERGY • TEMPERATURES VOLCANOES 8 © 2008 Encyclopædia Britannica, Inc. LIQUIDS, SOLIDS, AND GASES SE A
T GH RCH LI Mark whether each item below describes a solid (S), a liquid (L), or a gas (G). Some may match more than one form. • melts • turns into a liquid • keeps shape • has no shape or size • is frozen • has no shape DID YOU Answer: melts = S; turns into a liquid = S, G; keeps shape = S; has no shape or size = G; is frozen = S; has no shape = L, G © 2008 Encyclopædia Britannica, Inc. ★ KNOW? If you’ve ever sme lled g from a sto ve, you kn as coming ow it has odor. But an odd cooking g as has no What you odor. ’re smellin g with an o dor that’s is another gas easy to n mixed wit otice. It’s h the coo king gas people kn s o that ow when there’s a leak. 9