Why Is Space BLACK If The Universe Is Full Of Stars?

🔗 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. You've covered this topic twice before (the night-sky and "2 trillion galaxies" videos), so here's a short version angled for the Feynman channel to keep it distinct: If the universe were infinite, eternal, and unchanging, every line of sight would eventually end on the surface of a star — and the whole sky would blaze as bright as the Sun. This puzzle is called Olbers' Paradox, and the dark sky turns out to be one of the deepest clues we have about the universe. Three things make the night black. First, the universe had a beginning: it's 13.8 billion years old, so light from beyond a certain distance hasn't reached us yet. Second, space is expanding, stretching distant starlight into infrared and microwaves our eyes can't see — the leftover glow of the Big Bang still fills the sky at 2.7 degrees above absolute zero. Third, stars don't live forever; they burn out. Feynman loved questions like this because the simplest observation — look up at night — turns out to contain the history of everything. The sky isn't dark because there's nothing there. It's dark because the universe had a beginning. 🔔 Subscribe for more lectures that make you think differently. 📚 SOURCES: • Harrison, E. — "Darkness at Night: A Riddle of the Universe," Harvard University Press (1987) • Olbers, H.W.M. — "On the Transparency of Space," Astronomisches Jahrbuch (1826) • Penzias, A.A. and Wilson, R.W. — "A Measurement of Excess Antenna Temperature at 4080 Mc/s," Astrophysical Journal (1965) • Feynman, R.P. — "The Character of Physical Law," MIT Press (1965) #Feynman #Space #OlbersParadox #Universe #Cosmology #BigBang #Physics #FeynmanReborn