this post was submitted on 22 Feb 2024
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When Pope Gregory XIII briefly shortened the light-year in 1582, it led to navigational chaos and the loss of several Papal starships.

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[–] [email protected] 70 points 8 months ago (3 children)

Why not redefine lightyears to include a leap year every four years. Except when the number ends on 00, but only if it is not divisible by 400. Physics would be so much easier!

[–] [email protected] 11 points 8 months ago* (last edited 8 months ago) (2 children)

Well it's in fact easy to calculate...

To make it easier to visualize we'll start with year 400. From year 400 to year 799 you've got a leap year every 4 years except for years 500, 600, 700 and including year 400, so that's 25 leap years for the first century and 24 for the others.

So you've got 25 + (3x24) = 97 leap years

And 75 + (3 x 76) = 303 non leap years

(97 x 366) + (303 x 365) = 146097 days every 400 years which means a year is 365.2425 days long on average.

365.2425 x 24 = 8765.82 hours on average

8765.82 x 60 x 60 = 31 556 952 seconds per year on average

31 556 952 x 299 792 458 (speed of light per second) = a light year is 9460536207068016 meters long or 9460536207068.016 km long when adjusted to take leap years into consideration.

[–] [email protected] 2 points 8 months ago (1 children)

Okay, but now whenever you state one light year, it's just a normal year. When you state four, it is three normal ones and one leap year. So four times one light year would not equal four light years.

[–] [email protected] 6 points 8 months ago* (last edited 8 months ago)

You asked for a lightyear adjusted based on leap years, I provided the number. It's a bit more than 365 light days and a bit less than 366 light days, it's closer to the real distance covered by light during the time the earth goes around the sun.

Edit: Don't know why anyone would downvote me for providing what OP asked for in the first place, especially when their reply didn't really make sense in the context...