Do photons wear out? An astrophysicist explains light’s ability to travel vast cosmic distances without losing energy
- Written by Jarred Roberts, Project Scientist, University of California, San Diego
Light, whether from a star or your flashlight, travels at 186,000 miles per second.Artur Debat/Moment via Getty ImagesMy telescope, set up for astrophotography in my light-polluted San Diego backyard, was pointed at a galaxy unfathomably far from Earth. My wife, Cristina, walked up just as the first space photo streamed to my tablet. It sparkled...