tailieunhanh - Smog 2011 • Mark Braly • Mahlon Easterling

The human species' use of technology began with the conversion of natural resources into simple tools. The prehistorical discovery of the ability to control fire increased the available sources of food and the invention of the wheel helped humans in travelling in and controlling their environment. Recent technological developments, including the printing press, the telephone, and the Internet, have lessened physical barriers to communication and allowed humans to interact freely on a global scale. However, not all technology has been used for peaceful purposes; the development of weapons of ever-increasing destructive power has progressed throughout history, from clubs to nuclear. | .Caltech Libraries SMOG 3 504 01041 L105 A REPORT TO THE PEOPLE By Lester Lees Mark Braly Mahlon Easterling Robert Fisher Kenneth Heitner James Henry Patricia J. Horne Burton Klein James Krier w. David Montgomery Guy Pauker Gary Rubenstein John Trijonis TD C2 054 1972 cop. 2 ONMENTAL QUALITY LABORATORY alifornia Institute of Technology órted in part by the National Science Foundation Research Applied to National Needs RANN under Grant No. GI-29726 SMOG A REPORT TO THE PEOPLE By Lester Lees Mark Braly Mahlon Easterling Robert Fisher Kenneth Heitner Janies Henry Patricia J. Horne Burton Klein James Krier w. David Montgomery Guy Pauker Gary Rubenstein John Triịonis ENVIRONMENTAL QUALITY LABORATORY California Institute of Technology Supported in part by the National Science Foundation Research Applied to National Needs RANN under Grant No. GI-29726. Copyright 1972 by California Institute of Technology Library of Congress Catalog Card Number 72-86498 Printed in the United States of America by Anderson Ritchie Simon Los Angeles Art Director Patricia J. Horne Photography Walt .