John Daniel Kraus (1910-2004)
For a man whose career involved entire known universe, John Kraus had a remarkably insular upbringing. He was born and raised in Ann Arbor, Michigan, and earned his bachelor’s, master’s and doctoral degrees in physics, all at the University of Michigan.
Although his formative years took place on a few square miles of midwestern soil, Kraus had outsized ambitions when it came to exploring space. He first became enthralled that scientists were able to isolate radio waves from space and the prospects of studying those waves for clues to understand deep space. Throughout the late 1920s and the 1930s, the budding scientist was an avid radio amateur who 70 years later would be named to the Amateur Radio Hall of Fame.
After graduate school, Kraus stayed at Michigan where he was a member of the nuclear physics research team that designed and built a 100-ton cyclotron. He remained there until World War II, where he put his science expertise to work in defense of the allied nations. In his first job, Kraus worked on degaussing ships for the United States Navy. Such work meant decreasing or eliminating an unwanted magnetic field, making the vessel less vulnerable to German mines that were playing havoc with the British fleet. He also worked on radar countermeasures at the Radio Research Laboratory of Harvard University.
After the war, Kraus joined the faculty of Ohio State University in Columbus where he would stay throughout his academic career, eventually becoming director of the Radio Observatory. His radio astronomy team is credited with finding several of the farthest known orbital bodies, and produced a highly detailed survey of outer space.
Over the next several decades, Kraus experimented with different means of radio exploration of space and is credited with several inventions, including the helical antenna. Consisting of a conducting wire wound in the form of a helix, it is a popular tool for communicating with orbital spacecraft. He also pioneered development of the corner reflector, which is composed of three mutually perpendicular intersecting flat surfaces, which reflect electromagnetic waves back toward the source. Such devices are often used as radar markers and are frequently utilized on ships and lifeboats. The National Aeronautics and Space Administration (NASA) has placed numerous corner reflectors on the Moon to help measure the orbit more precisely than had been previously possible. Besides his inventions, Professor Kraus wrote several books, authored hundreds of technical articles and held several patents.
Mentally active to the very end, Kraus was viewed by many as one of the last links to an era that featured numerous scientific breakthroughs. At the time of his death in 2004, many in the scientific community fondly remembered Kraus for writing textbooks that made complex subjects accessible to many readers and for providing plain English solutions to complicated problems.