Higher Multipoles of the Cow

4 comments

• lhd1 54 minutes ago
  One of the cool facts about gravity is that the gravitational field of a body 'feels' spherical at a distance, even if those bodies are not spherical themselves. There are higher multipoles but they are increasingly suppressed the further you are from the body. So at least for gravity the spherical approximation turns out to be good and justified.
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  • DroneBetter 19 minutes ago
    for simulating gravity in particular you can do one better, since a sphere is in turn gravitationally indistinguishable from a point mass due to the https://en.wikipedia.org/wiki/Shell_theorem#Force_on_a_point...
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    • lhd1 5 minutes ago
      and you can do one better than that - Birkhoff's theorem, the relativistic analogue of the shell theorem.

      https://en.wikipedia.org/wiki/Birkhoff%27s_theorem_(relativi...
• turbostar 1 hour ago
  Anna Cramling, women’s international chess master, should review this paper, having popularized the Cow Opening.
• colechristensen 35 minutes ago
  Submission history

  From: Benjamin Lehmann [view email]

  [v1] Tue, 1 Apr 2025 07:55:39 UTC (2,401 KB)

  [v2] Wed, 1 Apr 2026 12:28:24 UTC (3,845 KB)
• Bowes-Lyon 1 day ago
  Hmmm… Today is Sep 1st, not Apr 1st. That cow is a bit out of season :)
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  • jitl 1 hour ago
    > Submitted on 1 Apr 2025 (v1), last revised 1 Apr 2026 (this version, v2)