Why Can Light Travel Billions of Years Without Running Out of Energy

🔗 https://oxadow.com/?v=qXBMGx-t7-8 — The Physics of Everything: gravity, light, time, quantum mechanics and the invisible world of electromagnetism, explained step by step. Explore all three illustrated PDF books in The Complete Library. 🔗 https://oxadow.com/mail/?v=qXBMGx-t7-8 — The Physics Letter: interesting physics news, remarkable discoveries and clear explanations, delivered to your inbox. Free to join. How can light travel billions of years across the universe without running out of energy? Every second, photons from distant galaxies cross unimaginable distances through empty space. Some have been traveling for over 13 billion years, yet they still reach our telescopes today. Why doesn't their energy simply run out? In this video, we explore the fascinating physics of light, photons, and energy conservation. Discover why light doesn't need fuel to keep moving, how photons survive journeys across billions of light-years, and why the expansion of the universe causes ancient light to lose energy through cosmological redshift. From Einstein's theory of relativity to the oldest light in the universe, the cosmic microwave background, we'll uncover one of the most remarkable properties of light and what it reveals about the nature of space, time, and energy. Topics covered: Photons, speed of light, conservation of energy, cosmological redshift, expanding universe, Einstein's relativity, cosmic microwave background, and astrophysics. #Physics #Light #Photons #Universe #Cosmology #Einstein #Space #Science