Untitled attachment

Notices where this attachment appears

1. Robert McNees (mcnees@mastodon.social)'s status on Wednesday, 31-Jan-2024 16:23:03 UTC Robert McNees

   in reply to

   The very next year, in 1959, Pound and Rebka exploited this effect to measure minute frequency shifts in photons moving up and down in the Earth's gravitational field.

   This red- and blue-shifting was one of the three "classical" tests of general relativity proposed by Einstein, and the only one that was experimentally out of reach when he proposed it in 1915.

   Pound and Rebka’s “Apparent Weight of Photons” is free to read, available here:
   https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.4.337