Maybe the easiest mnemonic is: the spacetime curvature* due to the sun, at the distance where an orbit takes 1 year, is the same as the curvature on a sphere with a circumference of 1 light-year.
For other bodies and orbits, just scale the circumference with the orbital period.
* This is the spacetime curvature in either of the two directions at right angles to a radial vector, pointing towards the sun.
In the radial direction, the curvature is negative and twice as much (so that all three curvatures sum to zero, which is always true in a vacuum).
Greg Egan
npub1qq…j5nhv
2026-01-13 05:40:52 UTC
in reply to nevent1q…428s
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npub1qqm7nu2qf25xd3mw6y6cyp4v2wr7ktf43ymp5wqz4u8jvz76ymtsjj5nhvSeen on
wss://relay.ditto.pubPublished at
2026-01-13 05:40:52 UTCEvent JSON
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