MicroFactzzz#0008 · 🌌 Cosmic Oddities
A Light-Year Doesn't Measure Time — It Measures Mind-Bending Distance
A light-year sounds like a unit of time, but it's actually the distance light travels in a year — almost 9.5 trillion kilometers.
The name trips up almost everyone at first: "year" suggests time, but a light-year is a distance — how far light, traveling at nearly 300,000 km/s, travels in one year.
Numerically that works out to about 9.46 trillion kilometers. The nearest star beyond the Sun, Proxima Centauri, sits over 4 light-years away — meaning its light takes more than four years to reach us.
Looking up at the night sky, you're literally looking into the past: some of the visible stars may have long since ceased to exist, their light still traveling.
Astronomers use this unit precisely because kilometers become absurdly unwieldy at galactic scale — the Milky Way is about 100,000 light-years across.
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Krulicza Nora
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