Page 44 - WINTER2019

The Dawn of Ultrasonics
Luis Alvarez (Nobel Laureate, close friend of Loomis, and writer of Loomis’s obituary) called Loomis the “last great amateur of science” (Alvarez, 1983), not in the modern sense of a “dabbler” but rather in the original French mean- ing “one who loves.” Loomis was never a mere dilettante but indeed became master of any endeavor he pursued. As a scientist, Loomis held 10 patents ranging from racing car toys to centrifuge microscopes to high-speed chronographs to long-range navigation (LORAN); he was coauthor of 32 scientific papers (including 5 in Science and 2 in Nature) and sponsor of another 48 from collaborators in his laboratory.
Loomis was, indeed, a quiet giant in the technologi- cal advances in the first half of the twentieth century. In addition to his adventures in high-intensity ultrasonics at Tuxedo Park, he was a pioneer in ultrafast chronography, an early developer of the electroencephalograph (EEG), and inventor of LORAN (the predecessor to GPS). Moreover, he funded the first cyclotron at University of California, Berkeley, and founded the MIT Radiation Laboratory, (Rad Lab; where airborne radar and radar-controlled antiaircraft artillery were developed). Loomis made contacts between physicists and Secretary of War Henry Stimson, who just happened to be Loomis’s favorite cousin. The Manhattan Project was remarkable for the lack of administrative road- blocks, a fact that Alvarez attributed “to the mutual trust and respect that Secretary of War Stimson and Loomis had. Loomis was in effect Stimson’s minister without portfolio to the scientific leadership of the Manhattan District — his old friends Lawrence, Compton, Fermi, and Robert Oppenheimer” (Alvarez, 1983, p. 33).
Despite his avoidance of publicity, Loomis did receive hon- orary degrees from Yale University (New Haven, CT); the University of California, Berkeley; and Wesleyan University (Middletown, CT); and in 1940, at the tender age of 53, he was elected to the National Academy of Sciences. In 1948, for his efforts in the development of radar, Loomis received both the US Presidential Medal of Merit (the highest civil- ian award) and from Britain the King’s Medal for Service in the Cause of Freedom. Lee DuBridge (director of the Rad Lab and then president of Caltech, Pasadena, CA) later commented, “Radar won the war; the atom bomb ended it.” Loomis was integral to the success of both. Alfred Lee Loomis was the most important scientist of the twentieth century who almost no one has ever heard of. And from all accounts, Loomis wanted it that way.
Figure 7. William T. Richards (1900–1940), coauthor with Loomis of the first paper on sonochemistry in 1927. Photo courtesy of the Conant (2002) family.
The Chemical Consequences of Ultrasound: William T. Richards
In the same year as the Wood-Loomis paper, Loomis pub- lished a second paper specifically on the chemical effects of ultrasound, this time with William T. Richards (Figure 7; Richards and Loomis, 1927). They had discovered that high- intensity ultrasound increased the rates of three classes of chemical reactions (initiation of detonation of an explosive, a hydrolysis reaction, and a clock reaction) and also reported other physical effects, including degassing of liquids.
At that time, Richards was a young assistant professor of chem- istry at Princeton University (Princeton, NJ). Richards was the
44 | Acoustics Today | Winter 2019