Remembering Gladys West: who used Einstein to create GPS

"Over the span of a single lifetime, the world has changed in ways that would have been virtually unimaginable in the first half of the 20th century. Two major breakthroughs that occurred in physics - relativity and quantum physics - suddenly made a number of previously unthinkable endeavors possible. From modern electronics to computers, smart phones, the internet, brain imaging and more, everyday life in 2021 is vastly different from what it was back when many of us were first born."

"One of those technologies that's been revolutionary for our society is GPS: the Global Positioning System. From anywhere in the world, signals can be transmitted by a network of medium-Earth orbit satellites to wherever your location is, pinpointing your position to an accuracy of better than 1 meter (3 feet) more than 95% of the time. Devices with the latest (L5) receivers, beginning in 2018, are now capable of reliably determining your location to within 30 centimeters (12 inches)."

"Unbeknownst to most people, however, the science underlying this technology was primarily developed by two people: Albert Einstein, whose theories of special and general relativity both play an important role, and Gladys West, a humble and largely-unheralded black woman who passed away at the age of 95 on January 17, 2026. Her scientific contributions enabled us to understand geodesy and the shape of the Earth well enough to make GPS technology possible."

Relativity and quantum physics enabled transformative technologies such as modern electronics, computers, smartphones, the internet, and brain imaging. GPS depends on a constellation of medium-Earth orbit satellites that carry precise position records and atomic clocks to broadcast timing signals worldwide. Typical consumer GPS achieves accuracy better than one meter over 95% of the time, while L5 receivers introduced in 2018 can reliably locate to about 30 centimeters. Albert Einstein's special and general relativity are essential for correcting satellite timing, while Gladys West's geodetic work and Earth-shape models provided the foundational understanding required to make GPS technology accurate and practical.

Read at Big Think