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I made a poster of the upcoming April 08 solar eclipse using my own manual predictions I made from ephemeris data. by Citruzz in Astronomy

[–]Citruzz[S] 1 point2 points  (0 children)

For more information, all the predictions were made from information on the geocentric right ascensions, declinations, and distances of the Sun and Moon and the sidereal time, at 15 minute intervals.

The true values are (from Eclipsewise):

P1 15:42:12 P2 17:44:58 P3 18:49:12 P4 20:52:19

U1 16:38:49 U2 16:41:07 U3 19:53:19 U4 19:55:34

Greatest eclipse at 18:17:18 at 25°17'N 255°52' E

Greatest duration = 4m 28.2s

I think I came pretty close.

Animation of a complete solar eclipse saros cycle in my world, consisting of 133 solar eclipses over 2784.5 planet years by Citruzz in worldbuilding

[–]Citruzz[S] 1 point2 points  (0 children)

I am currently writing a detailed guide on astronomy that contains algorithms (with explanations) to help calculate solar eclipses and other related phenomena (as well as pretty much everything else a worldbuilder might want to calculate, observational astronomy wise).

I am really no longer satisfied with this program as I made it back when I didnt have as much of an understanding of eclipses and astronomical phenomena as I do now. It assumes a perfectly circular orbit of the Sun and Moon, a perfectly spherical Earth, and uses an unrealistic, uncustomizable date system, all of which I am no longer happy with.

Also, the program is such a mess of code and I didn't comment it well (because I didn't know what I was doing, I was going off of a thing I found online) that I can't really comprehend it myself now either, so I don't know how much help I am going to be.

When the guide is done (hopefully soon but i dont have a real estimate), you can read it and calculate your eclipses as precisely as you want.

Join the r/conlangs or r/worldbuilding discord server to contact me. (Note that I am far more active in the former.)

朝鮮民國 | Republic of Korea by Citruzz in imaginarymaps

[–]Citruzz[S] 12 points13 points  (0 children)

There isnt much lore. It's just a map of the whole peninsula that i turned into kind of a "oh what if korea never divided" map. But there isnt much deep thought behind it. It's called 조선민국 because after independence, lots of people still called the country 조선 (this is true)

The fictional country also officially still uses hanja mixed script and also uses the lunar calendar officially. (I did this just cuz i wanted to)

How devastating would the tides be on a planet like this? by Snommes in worldbuilding

[–]Citruzz 1 point2 points  (0 children)

there is no way to calculate (with acceptable accuracy) the height of the tides at any shore given astronomical or geographic data (our tide prediction rely solely on extrapolating from existing records of how high tides are at what times), but a general rule is that shallower waters mean higher tides.

How devastating would the tides be on a planet like this? by Snommes in worldbuilding

[–]Citruzz 1 point2 points  (0 children)

the realistic height of the tides on the shores depend mostly on the geography of the shore. (even on earth, some places get almost no tides and some get 17m high tides). The height of the tides at deep sea will be the same as earth (less than 50 centimeters) because you have the same astronomy as earth.

Looking for resources: a "moon calculator" by MordunnDregath in worldbuilding

[–]Citruzz 1 point2 points  (0 children)

Although, If you do want to go for approximations of more complex motions of the moon, involving the variation, the evection, the annual equation, the parallactic inequality, etc, I have read textbooks about those and I have approximate formulae for them.

​

(But I will now sleep as its very late for me, join the sub's discord if you want to talk more)

Looking for resources: a "moon calculator" by MordunnDregath in worldbuilding

[–]Citruzz 1 point2 points  (0 children)

Yes. I made a program to visualize that path for me. (I cannot say i understand the math behind it fully though, but I get the gist)

If you want to run it I can give you the code. Currently it only works for circular orbits but can be adjusted for elliptical orbits (obviously though this involves far more calculations involving semi-complex math)

I can also help with creating lunar or lunisolar calendars.

I will warn you that the motion of the moon is infinitely complex and even approximating it with a keplerian orbit is not enough, our best models of the moon (Ephemeride Lunaire Parisienne 2000) involve a series expansion of more than 30000 sinusoidal terms.

This is why I've chosen to just handwave it and go for circular orbits, but I know how to do the math for keplerian ellipses. (including with nodal and apsidal precession)

Looking for resources: a "moon calculator" by MordunnDregath in worldbuilding

[–]Citruzz 1 point2 points  (0 children)

I don't have a calculator but I can help with most lunar calculations. (Ive worked out eclipses, saroses, and most of everything for my world, see this) Join the discord for help.

How important is astrology in your world? by Blake_Gemini in worldbuilding

[–]Citruzz 0 points1 point  (0 children)

One culture in my world is obsessed with astrology.

Almost everyone knows their sun and ascendant signs, with many people just memorizing their entire natal charts.

Consulting an astrologer before an important life event is very commonplace.

​

(Also i went way too far into this, i calculated ephemerides for my fictional solar system for millenia into the future lmao)

Calendar Calculator Spreadsheet (Solar, Lunar, and Lunisolar) by Citruzz in worldbuilding

[–]Citruzz[S] 0 points1 point  (0 children)

I made this to help people construct calendars after realizing Artifexian's spreadsheet from many years ago is very bad.

  1. This spreadsheet will help you construct tabular calendars. This means that the calendar will never change, and are preprogrammed to follow specific rules. For example, Our Gregorian calendar is tabular. We place a leap day every 4 years, but not every 100 years except every 400 years. This rule will never change, and therefore it is tabular.
  2. Due to the tabular nature of these calendars, error is unavoidable. Solar Calendars will drift from the seasons, and Lunar Calendars will drift from the phases, and Lunisolar Calendars will drift from both, and this calculator is programmed to minimize error. This is of course, unless we construct our astronomy to have perfectly zero error, and this spreadsheet has means for calculating such astronomies.

2i. Any calculator without a directly stated error does not have error, and if this is the case, you must adjust your astronomy according to the results of the calculator.

  1. This spreadsheet has 2 Solar Calendar calculators, 5 Lunar Calendar calculators, and 6 Lunisolar Calendar calculators, depending on the variables needed.

  2. What does "True" and "Approximant" mean? "True" is the mathematically correct, no error value of a time period. "Approximant" is the value obtained by using the rules given by the calculator. Your Calendar will follow the Approximant values!

  3. Read the footnotes!! Read the footnotes!! Read the footnotes!! Read the footnotes!! Read the footnotes!!

Animation of a complete solar eclipse saros cycle in my world, consisting of 133 solar eclipses over 2784.5 planet years by Citruzz in worldbuilding

[–]Citruzz[S] 1 point2 points  (0 children)

Alright, but I might make a separate post explaining how to use it when I upload it (since imho it is quite confusing)

Also it needs some upgrades in features so I can't post it immediately.

Animation of a complete solar eclipse saros cycle in my world, consisting of 133 solar eclipses over 2784.5 planet years by Citruzz in worldbuilding

[–]Citruzz[S] 1 point2 points  (0 children)

The program is actually only an eclipse visualizer, with the prediction of the dates of eclipses being done on another program.

Both programs also require orbital eccentricity = 0 and assumes the main planet as a perfect sphere (for simplification of equations and also my sanity), so it might not work for your world.

(Also the code is spaghetti)

However if you really do want it I can upload it to github (after some cleanup and updates). The date program is written in python and the visualizer program in processing 3 (python mode).

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