In the history books of World War II, several inventions often take center stage. The atomic bomb, radar technology, and different military tactics have all earned their rightful places in the annals of this world war. The proximity fuze, a less well-known innovation nonetheless, was as important in determining how the conflict would unfold. It was the first 'smart' weapon and transformed WWII warfare.

According to Malwarwick on Books, the importance of the proximity fuze in preventing Nazi superweapons like the V-1 "buzz bomb" is highlighted in Jamie Holmes' book "12 Seconds of Silence." Moreover, it played a crucial role during the battles at the Philippine Sea (June 19-20, 1944) and the Battle of the Bulge (December 16, 1944-January 25, 1945).

Early in World War II, the ratio of artillery rounds fired to enemy aircraft shot down, or "rounds per bird," was 20,000 to 1. In essence, it meant that anti-aircraft weapons could only successfully shoot down hostile aircraft by chance.

The main challenge was to build a mechanism that could detonate an artillery round near an attacking aircraft without a direct impact or to get the shell to detonate close enough to the aircraft that shrapnel would destroy it. Hence, American and British scientists and engineers explored possible solutions, resulting in the proximity fuze.

The dogged efforts of a team of American engineers and scientists known as "Section T" led to the development of the proximity fuze. As they worked to construct the fuze, this team, under the direction of physicist Merle Tuve, encountered obstacles and bureaucratic red tape. The wartime instability in the American military and a failed British attempt exacerbated the problems. However, the proximity fuze ultimately proved to be a game-changer.

A proximity fuze has a clever mechanism. The body of the shell serves as an antenna for a microtransmitter within the shell, which continuously emits a radio wave. The bouncing wave from the shell communicates the target's vicinity as it approaches a reflecting object, setting off the explosion when it gets close enough.

A Filipino Teacher's Involvement

Emma Rotor was a crucial contributor to the creation of the proximity fuze, even though her name may not be well known in this context.

According to a Manila Times article, Emma came to the US in October 1941, months after her husband, Arturo Rotor, started graduate school at Johns Hopkins. She had initially intended to pursue physics, but the start of WWII derailed her ambitions. She did not let it stop her, and for a short time, she served as a stenographer at Baltimore's Enoch Pratt Free Library.

Emma played a crucial role in January 1944, when Arturo joined the Philippine government in exile. She joined the Ordnance Development Division of the National Bureau of Standards, now the National Institute of Standards and Technology (NIST), which was headed by radio engineering pioneer Harry Diamond. Science News noted that Emma was employed as a physicist during World War II to assist experimental research on new ordnance weaponry. She had to develop, build, and test mechanical, electrical, and radio equipment among her tasks.

Despite her difficulties, Emma's efforts were crucial. She also co-authored research and published scientific articles on subjects like "Air travel required for release of arming cover" and "Measurement of dynamic propeller unbalance." The 1946 summary report on the Ordnance Development Division's research into proximity fuzes, titled "Radio Proximity Fuzes for Fin-Stabilized Missiles," eventually referred to these studies.

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Emma Rotor's commitment led her to do ground-breaking research on bomb trajectories. Her significant contribution, "Evaluation of the Toss Technique," co-authored with Albert G. Hoyem, detailed the outcomes of lengthy experiments designed to pinpoint the exact bomb trajectories. This important study was included in the 1946 publication "Bomb, Rocket, and Torpedo Tossing," a thorough compilation of scientific articles.

Emma's contribution stands out not just for her part in developing these critical studies but also for her meticulous oversight of the review and compilation of the final publication. The scientific community praised her meticulousness. In this group of male-dominated authors, Emma Rotor was the only woman.

A Long-Lasting Legacy

Arturo and Emma Rotor left a lasting legacy. Despite not having children of their own, their granddaughter Ria Unson and niece Delia Unson have loving memories of Emma.

Emma's exceptional teaching skills were highlighted by Delia Unson, a retired clinical psychologist, who noted that Emma had a special gift for making arithmetic interesting and simple for her students at Assumption College in Makati.

Artist Ria Unson remembers the kindness and acceptance that characterized Emma's personality. She said Emma continues to influence her creative endeavors.

It's interesting to note that Emma's family was mostly ignorant of her contributions to the study of weaponry. She kept this area of her life quiet because of her modest demeanor. According to Science News, when questioned by a family member about her work on WWII weaponry, Emma Rotor smiled a little and said, "I worked on the fuze."  Years later, Ria showed the family Emma's works in the proximity fuze's development and that's only when they understood.

The legacy of Emma Rotor stands as a monument to the many unsung heroes whose actions, though sometimes hidden, played key roles in shaping history.

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