Why the Past Might Still Exist? What Carl Sagan Found Unsettling скачать в хорошем качестве

Why the Past Might Still Exist? What Carl Sagan Found Unsettling

Why the Past Might Still Exist? What Carl Sagan Found Unsettling You think the past is gone. Like reality deletes it. Finished. Over. Erased. Fine. But where did it go? When did it stop existing? And what, exactly, is it about the universe that makes something “not now” turn into “not real”? Most people never answer that. They repeat a phrase that sounds like an answer. “Time moves forward.” “The past is behind us.” “You can’t go back.” But that’s not an explanation. That’s just a description of the feeling. When you actually ask whether the past still exists — not as memory, not as nostalgia, but as physics — you run into something that breaks your model of reality. Let me show you. SOURCE PACK Claim: “Light from the Sun takes about 8 minutes and 20 seconds to reach Earth.” Source: NASA Space Place — All About the Sun Claim: “Andromeda is about 2.5 million light-years away (so what you see is ~2.5 million years old).” Source: NASA Science (Hubble Messier Catalog) — Messier 31 Claim: “Special relativity is built from the invariance of light speed and replaces absolute time with a new spacetime structure.” Source (Primary): Einstein (1905) — On the Electrodynamics of Moving Bodies (English translation PDF) Claim: “Relativity of simultaneity (the train + lightning idea): observers in different motion states can disagree on what is simultaneous, and both are correct.” Source (Textbook): Taylor & Wheeler — Spacetime Physics (Train Paradox / simultaneity) Claim: “GPS requires relativistic correction; the net offset is ~38 microseconds/day, which corresponds to roughly 10 km/day positional error if ignored.” Source: Peterson & Chase (UNCW) — GPS, Atomic Clocks, and Relativity (PDF) Claim: “The direction we feel as ‘time’s arrow’ is linked to entropy increase (thermodynamic time asymmetry).” Source: Stanford Encyclopedia of Philosophy — Thermodynamic Asymmetry in Time