Do photons wear out? An astrophysicist explains light’s ability to travel vast cosmic distances without losing energy

Light, whether from a star or your flashlight, travels at 186,000 miles per second. Artur Debat/Moment via Getty Images – By Jarred Roberts, Project Scientist, University of California, San Diego Published: 2025 May 20 – My telescope, set up for astrophotography in my light-polluted …