Emma Unson Rotor (May 18, 1913 – September 6, 1998) was a Filipino-American physicist and mathematician whose pioneering work during World War II significantly contributed to the development of the proximity fuse, a crucial advancement in military technology that played a critical role in the Allied victory of World War II.

[1][2][4] Hired as a physicist under a wartime appointment, she supported experimental investigations into the development of new ordinance devices, which are military tools or weapons designed for combat.

[2] Rotor and her colleagues developed the proximity fuse, a sophisticated device designed to detonate missiles as they approach their targets, rather than upon direct impact.

[1][8][4] Her work involved complex calculations and applying her knowledge of physics and mathematics to solve various technical challenges such as limiting the vibration of the devices.

[1][8] She co-authored and published several scientific articles, including Air Travel for Arming Covers and Measurement of Dynamic Propeller Unbalance, which were cited in a 1946 summary report of the Ordinance Development Division’s work on proximity fuses.

One of her notable contributions, co-authored with Albert G. Hoyem, was "Evaluation of the Toss Technique," which detailed the results of experiments to determine exact bomb trajectories.