Comments on Could there be a way for a solar system to be very precise, so that the lunar calendar and solar calendar align?
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Could there be a way for a solar system to be very precise, so that the lunar calendar and solar calendar align?
I know that this is a bit silly, but I want to make a calendar for my world and I'm really worried about having to do leap years and such to ensure continuing accuracy.
Inaccuracy isn't an option; many worlds could simply have a calendar that gradually gets out of line, but the people in this world are very particular about things being easy to understand yet accurate and informative. This would extend to their calendars, I'm sure.
So, I think that the effects of gravity on other planets can affect rotation - I believe the moon is slowly slowing Earth down, right? So, would it be feasible for the sun and planet to influence each other to make sure that years are a whole number of days and that years are a whole number of months?
(This sounds like a stretch, even to me, but might be something about the frequencies of the minor oscillations in orbit plus some other factor - I have limited knowledge of any physics at all, let alone orbital mechanics, so someone smarter than me might know something.)
Secondly, could it be possible for this to occur for a planet that is a binary planet? My system is quite lopsided, the centre of the two planets' orbit is only JUST outside of the main planet, but it is still enough to be a binary planet.
(If this is impossible, advice on creating a simple yet highly effective calendar for these very fussy people would be nice.)
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First, the fussiness of the people has absolutely no bearing on how their solar system ended up. It is what it is, whether they like it or not.
As for the physics, you are basically asking for rotations of the planet and its orbit around the star to be integer multiples. Yes, that can happen, but realistically only for small integers. Look up something called "tidal locking" or "tidal resonance". For example, our moon is tidally locked to the earth. In this case its spin and orbit have a ratio of 1:1.
Mercury has a spin to orbit ratio of 3:2. That's only possible because Mercury is so close to the very massive sun.
Tidal locking and resonance rely on the difference in gravity of the body being orbited between the near and far side of the orbiting body. The forces keeping a body in resonance decrease at higher ratios. Therefore, most resonances out there are 1:1, which is full tidal locking. Anything more requires orbiting close to something massive.
If you're looking for something like earth orbiting the sun with a resonance of 365:1, that's not going to happen. First, earth is too far from the sun so that even 1:1 resonance is unlikely. Venus is not tidally locked or in any resonance with the sun, and it's closer to the sun than earth. Second, 365:1 is so extreme that it's not going to happen.
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