1553
Sea Level (europe.pub)
submitted 9 months ago by to c/science_memes@mander.xyz
173 comments fedilink hide all child comments
 

Alt text: They're up there with coral islands, lightning, and caterpillars turning into butterflies.

you are viewing a single comment's thread
view the rest of the comments
[–] 1 point 9 months ago (2 children)

Can you provide a source for 14 orbits? Everything in my search results says 13 and some change.

Wikipedia says one sidereal month is 27.321661 days and a sidereal year is 365.256 days.

365.256/27.321661 ≈ 13.37

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 2 child comments
    •
  • [–] 1 point 9 months ago (1 child)

    a sidereal year is 365.256 days.

    No. A sidereal year is 366.24 days.

    And 11 days isn't "and some change"

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 2 points 9 months ago

    The figures in my post are ephemeris days since that's the way Wikipedia lists them.

    https://en.wikipedia.org/wiki/Sidereal_year

    https://en.wikipedia.org/wiki/Lunar_month#Sidereal_month

    "And some change" is a phrase to refer to a number following a decimal point, meaning the sources I find claim there are thirteen point something sidereal months per year, at a figure too low to round to 14. Here are some example sources:

    https://en.wikipedia.org/wiki/Orbit_of_the_Moon#Lunar_periods

    http://scienceline.ucsb.edu/getkey.php?key=1126

    I still can't find a source which says the moon makes 14 sidereal orbits per year, using any definition of year.

  • permalink
  • fedilink
  • source
  • parent