Part 1

OUR ATOMIC WORLD

by C. Jackson Craven

THE STORY OF ATOMIC ENERGY

U.S. ATOMIC ENERGY COMMISSION Division of Technical Information Understanding the Atom Series

The Understanding the Atom Series

Nuclear energy is playing a vital role in the life of every man, woman, and child in the United States today. In the years ahead it will affect increasingly all the peoples of the earth. It is essential that all Americans gain an understanding of this vital force if they are to discharge thoughtfully their responsibilities as citizens and if they are to realize fully the myriad benefits that nuclear energy offers them.

The United States Atomic Energy Commission provides this booklet to help you achieve such understanding.

{Edward J. Brunenkant} Edward J. Brunenkant, Director Division of Technical Information

UNITED STATES ATOMIC ENERGY COMMISSION

Dr. Glenn T. Seaborg, Chairman James T. Ramey Wilfrid E. Johnson Dr. Theos J. Thompson Dr. Clarence E. Larson

OUR ATOMIC WORLD

by C. Jackson Craven

CONTENTS

THE GREEKS WERE CURIOUS ABOUT MATTER 1 THE ATOMIC THEORY IS CONFIRMED 2 CATHODE RAYS SHOW ATOMS CONTAIN SMALLER PARTS 3 RADIOACTIVE ATOMS DISCOVERED 5 RUTHERFORD FINDS THE ATOMIC NUCLEUS 6 THE PROTON IS RECOGNIZED 8 ISOTOPES ARE DISCOVERED 9 THE ALCHEMISTS’ DREAM COMES TRUE 10 SOME PARTICLES HAVE NO ELECTRIC CHARGE 13 MATTER IS ENERGY; ENERGY IS MATTER 14 NUCLEI CONTAIN ENERGY 15 CHRONOLOGY 18 FISSION IS EXPLAINED 20 THE FISSION BOMB IS EXPLODED 23 NUCLEAR ENERGY IS NEEDED FOR THE FUTURE 25 FUSION HAS POTENTIAL 26 ISOTOPES HAVE MANY USES 29 RADIOISOTOPES AT WORK 30 THE ATOMIC ENERGY COMMISSION 31 TOWARD AN INTERNATIONAL ATOM 33 SUGGESTED REFERENCES 35

United States Atomic Energy Commission Division of Technical Information Library of Congress Catalog Card Number: 63-64918 1963; 1964 (Rev.)

C. JACKSON CRAVEN is a teacher’s teacher as well as a student’s teacher, and has had an active career aiding understanding of atomic energy as a member of the University of Tennessee faculty and on the staff of the Oak Ridge Institute of Nuclear Studies. He has conducted short courses to instruct groups of high school science teachers in nuclear energy, and has served in a key capacity in training Institute demonstration-lecturers who visit high schools throughout the nation.

Dr. Craven worked during World War II for the Manhattan Project, which built the first atomic bomb. He earned bachelor’s and graduate degrees at the University of North Carolina, and later taught physics and mathematics at Delta State Teachers College and at Furman and Emory Universities.

His research interests include infrared spectroscopy, gaseous diffusion through porous media, and the physical properties of fibers.

OUR ATOMIC WORLD

By C. Jackson Craven

The story of atomic energy evolves from the curiosity of people concerning the nature and structure of matter, the stuff of which all material things are made.

The Greeks Were Curious About Matter

Certain philosophers of ancient Greece—Democritus for one—were fascinated by the question: what is matter? You can imagine one of the philosophers saying to his pupils:

“Gentlemen, let us consider a piece of cheese. With a knife we can cut it in two, thus obtaining smaller pieces. We can then cut one of these smaller pieces in two, obtaining still smaller pieces. We can think about repeating this process over and over to get smaller and smaller pieces of cheese. Now can this process be continued without limit, or will a time come when we arrive at the smallest possible piece of cheese? In other words, is there a piece so small that we must have at least that much or none, with no choice in between?”

It is probable that most people who thought about this question at all during the next two thousand years answered the last question in the negative. The prevailing notion was that matter was continuous, with no theoretical limit as to how small a piece of cheese, or anything else, might be.

This concept was humorously expressed by the British mathematician Augustus De Morgan (1806-1871) in these lines:

Great fleas have little fleas upon their backs to bite ’em, And little fleas have lesser fleas, and so, ad infinitum.

The Atomic Theory Is Confirmed