On a clear night 77 years ago, a beam of light hurtled across the night sky from the top of Mt. Wilson to Lookout Mountain near Mt. Baldy and back again.
With that, the speed of light was calculated with a measure of accuracy for the first time.
It's easy for people to travel to the Mt. Wilson Observatory and stand on the ground where Albert Michelson, the first American to win the Nobel Prize in physics, worked for four years to accurately calculate the speed of light in 1926.
Twenty-two miles across the San Gabriel Mountains, however, the site of the mirror that bounced the light back to Michelson is impassable to even the most-determined hiker.
The historic site on Lookout Mountain, located on the southwestern ridge of Mt. Baldy, is slowly being reclaimed by the rugged terrain, but two Claremont men are trying to make sure it doesn't happen.