How Can Gravity Trap Light If Light Has NO Mass

🔗 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. Newton's gravity can't explain it. In Newton's picture, gravity is a force between masses — and a photon has no mass, so there should be nothing for gravity to grab. Yet light bends around the Sun, and it can't escape a black hole. The answer is Einstein's: gravity isn't a pull on things. It's the shape of spacetime itself. Mass and energy curve space and time, and everything moving through them — planets, people, and light — follows the straightest path the curved geometry allows. Light doesn't need mass to fall. It only needs to travel through bent spacetime. The proof came in 1919, when Arthur Eddington measured starlight passing near the Sun during a total eclipse and found it deflected by the amount Einstein predicted — twice the value a Newtonian calculation gives. And there's a second reason gravity can act on light: in relativity, energy gravitates too, and a photon carries energy and momentum. Near a black hole, the curvature becomes extreme. At the event horizon, spacetime is bent so severely that every possible direction a light ray could travel — even straight "outward" — leads further in. The light isn't being pulled back like a thrown ball. There is simply no path left that leads out. Light still moves at light speed. It just has nowhere to go. 🔔 Subscribe for more lectures that make you think differently. 📚 SOURCES: • Einstein, A. — "The Foundation of the General Theory of Relativity," Annalen der Physik (1916) • Dyson, F.W., Eddington, A.S. and Davidson, C. — "A Determination of the Deflection of Light by the Sun's Gravitational Field," Philosophical Transactions of the Royal Society (1920) • Feynman, R.P. — "The Feynman Lectures on Physics, Volume II," Caltech (1964) — curved space • Misner, C.W., Thorne, K.S. and Wheeler, J.A. — "Gravitation," W.H. Freeman (1973) #Feynman #Gravity #Light #BlackHole #Einstein #GeneralRelativity #Physics #FeynmanReborn