Big Ear was the Ohio State University radio telescope. Originally used to survey the sky for natural radio sources, it was later utilized for a search for extraterrestrial intelligence (SETI). Among its many accomplishments was the famous "Wow!" SETI candidate. John Kraus was the longtime director of the OSU Radio Observatory and the author of a seminal textbook on radio astronomy. Though the title (and front cover of my copy) suggests the book is about the radio telescope, it is really an autobiography by Kraus.
Kraus has led what sounds to be wonderfully peripatetic physical and intellectual life. He started as an amateur radio operator and has worked on cyclotrons, noise suppression in paper making machines, ship degaussing for the US Navy in World War II, antenna design and research, and radio astronomy. His various exploits took him across the US and around the world, both physically and virtually, the latter thanks to his ham radio kit. He tells delightful stories of trying not to pick up a prostitute in Berlin, of watching Hitler speak, and of touring Stalinist Russia.
Before becoming a radio astronomer, Kraus was a ham radio operator who constructed many of his own radio sets and became quite well known for his skill in doing so. In a time when radio stations are owned by national corporations, it is fascinating to read about the days when radio stations were local in flavor and a trip to a local radio station might result in one getting on the air, if the DJ was sufficiently impressed with you.
The later chapters of the book describe the construction and operation of the Big Ear telescope itself. In many ways these chapters trace out the arc of radio astronomy. Radio astronomy was discovered by accident and not appreciated initially. Similarly, Kraus' interest in radio astronomy was spurred by a visitor from England who knew a lot about radio telescopes but was visiting to discuss Kraus' work on helix antennas. The 1960s and 1970s were the heyday of radio astronomy and Big Ear. Radio astronomers were discovering a new and much more varied Universe. Not only were there stars and galaxies, but the Universe was also populated with pulsars---dense stellar remnants having more mass than the Sun compressed into a sphere only 20 km in diameter and spinning about once per second---and quasars---distant cores of other galaxies that not only emit more radiation in a second than the Sun emits over its entire lifetime but do so from a volume not much larger than the solar system. Other objects were known previously but looked much different when seen with radio telescopes. Most stars were found to be undetectable while the remnants of their explosions, called supernova remnants, can be powerful radio emitters.
Big Ear played an important role in this revolution. The Ohio Sky Survey undertaken at the Big Ear (and described in the book) was, at its time, one of the most sensitive surveys of the entire northern sky and proved useful in identifying those rare sources that prove Nature still has surprises for us. Indeed, this technique pioneered by the Ohio Sky Survey, the Cambridge 3C and 4C surveys, and the Parkes surveys continues to this day. Often one of the first things done with a new telescope, particularly one observing the sky at a previously unexplored wavelength, is to survey the sky. The hope is to find previously unknown sources. Since the pioneering radio work, this technique has been used with great success in infrared, extreme ultraviolet, X-ray, and gamma-ray wavelengths. Kraus writes, with justifiable pride, about the Ohio Sky Survey's role in this work. Among other discoveries, quasars discovered in the Ohio Sky Survey held the record, at least for a time, for the most distant known objects.
After a while Big Ear's focus changed from detecting natural radio sources to searching for transmissions from extraterrestrial civilizations. As such it was the first dedicated, long-term SETI program. There had been previous searches, but Big Ear set the standard in terms of 24/7 monitoring of the sky for any transmissions. Accordingly it was the Ohio State SETI program that detected the first bona-fide SETI candidate, the "Wow!" candidate.
Along the way we hear how Kraus met with various luminaries of 20th century physics and astronomy, including physicists Werner Heisenberg and Enrico Fermi, radio astronomers Grote Reber and Martin Ryle, and SETI pioneers Frank Drake and Carl Sagan.
The book does has a few weaknesses. For instance it would have been nice to hear a bit more about the "Wow!" detection. Kraus continually describes himself as "listening" to the sky, even though a radio telescope watches the sky. He undoubtedly continues the misconceptions of many people who think that radio waves are sound. In a few places he also uses terminology that will probably be familiar only to radio astronomers or radio engineers (e.g., a 50 K receiver).
These weaknesses are certainly minor and should not deter any readers. This book is a marvelous history of both radio astronomy and science and technology in the 20th century. I recommend it highly.
Epilogue: All scientific instruments eventually reach the end of their useful lifetime, when outfitting them with the latest technology becomes more expensive than simply building something new. This did not happen to Big Ear. As was foreshadowed toward the end of the book, Big Ear was torn down in 1999 December in order to build a golf course.
jlazio@patriot.net>