Talk: A Tale of Two Bridges and Round Earth

The Peninsula Astronomical Society is delighted to welcome Clinton Lewis to our November 2024 meeting for his talk: A Tale of Two Bridges and Round Earth

Topic
Can you measure the radius of the Earth from an office window? An unusual photograph through a telescope of two San Francisco bridges clearly shows the curvature of the Earth. Measurements from this photo, bridge dimensions, and a few calculations result in a calculated radius of the Earth surprisingly accurate! The presentation will review three models of the Earth and the line of sight to the bridges, each successively more complex, but with increased accuracy as the payoff. Compared to the approach employed by Eratosthenes in 200 BC, a more complex approach adjusts for the refraction of light and yields results closer to USGS estimates for the Earth’s radius.

Speaker Bio
Clinton Lewis a former Astronomy Teacher at West Valley College in Saratoga, an avid amateur astronomer and member of the Peninsula Astronomical Society. His other interests include modeling various forces on low Earth satellites. Clinton’s former day jobs included running a planetarium, determining space satellite orbits, and modeling DNA base detection in the 96 capillary sequencer used in the human genome project.

Logistics
Please join us in person at the Los Altos Library, or on Zoom: https://us06web.zoom.us/j/82502011675?pwd=onLEExL9Hbl8mxJEtMe2MGO7SyoeIi.1
Meeting ID: 825 0201 1675
Passcode: 3.14152595