Table of Contents

In This Issue

The Positron — Its Discovery and Impact on Particle Physics
by Robert Bacher
A distinguished physicist introduces this special issue.

The Picture That Was Not Reversed
by Eugene Cowan
A three-part story that begins with Carl Anderson's discovery of the positron, is followed by a commentary by Nobel Laureate Richard Feynman and quotations from the scientific literature of the early 1930s, and finishes with a few not-so-scientific items.

Unraveling the Particle Content of Cosmic Rays
by Carl Anderson
An excerpt from a paper prepared for an international conference of historians of science, held in the fall of 1980 at Fermilab.

Recollections of 1932-33
A portion of an interview with Milton Plesset on his memories of Caltech in the year that the positron was discovered.

A Man Who Speaks Swedish
A brief, illustrated biography of Carl Anderson

Cosmic Rays — A Scientific Cornucopia
by Robert Leighton
Research on the cosmic radiation has led to a wealth of scientific discoveries.

Fifty Years of Antimatter
by John Schwarz
A short paper on the concept of antimatter and its importance to particle physics and to cosmology.

The Search for Fractional Charges
by Robert McKeown
A brief look at some of the newest research in particle physics.

Random Walk
With Us This Year — Coming Up — In Memoriam — Counterpoint