Episode Description

Sallie Pero Mead was first hired at AT&T in 1915 as a “computer”—a human calculator—shortly after completing her master’s degree in mathematics at Columbia University. Before long she started working on the company’s transmission engineering team as both a mathematician and an electrical engineer. She and her team developed and tested hollow metal tubes used as waveguides: structures that confine and direct electromagnetic waves. In 1933 they discovered a new way that hyperfrequency waves could propagate down these tubes, and this made radar technology possible—just in time for use in World War II.


  • Greg Coxson, a Professor of electrical engineering at the Naval Academy in Annapolis, Maryland
  • William Haloupek, a retired mathematician who worked in the radar engineering field for 10 years


  • Erica Huang


Erica Huang

Senior Producer

Erica is a sound designer, producer, and mix engineer for podcasts and radio. She’s contributed to shows for PRX, The Atlantic, Prologue Projects, Vox, Pushkin, Audible, LWC Studios, CNN, and TED. Erica is also the studio manager at Good Studio, where she’s recorded for Radiolab & This American Life. Ask her about analog synths and mechanical keyboards. Or don’t.


Episode Transcript

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