Secret Clocks: Einstein’s Relativity, the US Military, and the Global Positioning System

  • Physics and Astronomy Colloquium

May 3, 2024 3:30 PM
PAIS-1100, PAIS

Host:
Dinesh Loomba
Presenter:
Dr. Dave Kaiser (MIT)
Zoom link -- contact Physics Dept for the passcode
For nearly a decade, beginning in the mid-1970s, a debate unfolded among physicists and engineers over how best to include effects from Einstein's general theory of relativity in the new military technology now known as the Global Positioning System (GPS). Although some exchanges were published in the open scientific literature, much of the debate played out behind the scenes, in memos, reports, and special review sessions arranged by the U.S. military. Theoretical physicists who had no relationship with the project criticized early efforts to incorporate relativistic effects within GPS designs, complaining that significant information was not shared by military contractors. Other experts in relativity, who consulted more closely with the U.S. Air Force while GPS was under development, responded that the outside critics had little relevant experience with real-world engineering applications, and that their criticisms amounted to mathematical irrelevancies. Throughout the debate, few doubted that relativity --- with its counterintuitive notions of space and time --- needed to be taken seriously in the design and operation of GPS. Rather, they disagreed over how best to incorporate deep lessons from relativity in an engineering-relevant way, at a time when the stakes for the new military technology loomed large.

Upcoming Events

MIGDAL Optical TPC: Fitting Observations to Simulation
Dustin Edgeman (UNM)
Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars
May. 6, 2:00 PM
PAIS 3205

Development of next generation readout for Cosmic Microwave Background instruments
Wilber Dominguez (UNM)
CART Astrophysics Seminar Series
May. 8, 2:00 PM
PAIS 3205

No Colloquium on May 9
TBD
Physics and Astronomy Colloquium
May. 9, 3:30 PM - May. 9, 4:30 PM
PAIS 1100

Measuring Cosmic Sound with the Dark Energy Spectroscopic Instrument
Daniel Eisenstein (Harvard)
Physics and Astronomy Colloquium
May. 16, 3:30 PM - May. 16, 4:30 PM
PAIS 1100

Department Convocation

Special Talk
May. 17, 12:00 PM - May. 17, 1:30 PM
PAIS 1100 and Lobby