Pasadena in Los Angeles County, California — The American West (Pacific Coastal)
The First Known Antiparticle
Historic Physics Site
Photographed By Craig Baker, September 29, 2018
1. First Known Antiparticle Marker
Near this site, in August 1932, Carl David Anderson photographed the track of a cosmic ray particle in his cloud chamber. He identified this particle as the positron — the first known antiparticle.
Historic Physics Site, Register of Historic Sites, American Physical Society.
Erected by American Physical Society.
Topics. This historical marker is listed in these topic lists: Education • Science & Medicine.
Location. 34° 8.194′ N, 118° 7.55′ W. Marker is in Pasadena, California, in Los Angeles County. Marker can be reached from California Boulevard, 0.1 miles east of Wilson Avenue. Located on the Cal Tech campus, at the north-east corner of the Bridge Labs Buildings. Touch for map. Marker is at or near this postal address: 1200 E California Boulevard, Pasadena CA 91125, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Karman Laboratory of Fluid Dynamics and Jet Propulsion (about 300 feet away, measured in a direct line); Throop Memorial Garden (about 300 feet away); William Morris Davis, 1850-1930 (about 300 feet away); Iris Garden (about 400 feet away); Hameetman Center (about 700 feet away); Beckman pH Meter (approx.
this page online
Photographed By Craig Baker, September 29, 2018
2. First Known Antiparticle Marker
Photographed By Craig Baker, September 29, 2018
3. Nearby Sign
Near the seismology lab at Wilson & California Ave.
Credits. This page was last revised on January 30, 2023. It was originally submitted on October 2, 2018, by Craig Baker of Sylmar, California. This page has been viewed 222 times since then and 13 times this year. Photos: 1, 2, 3. submitted on October 2, 2018, by Craig Baker of Sylmar, California. • Andrew Ruppenstein was the editor who published this page.
