FrostFire

I very much love your theory and it does present some interesting points from the perspective you have given. however i believe that some of it doesn't add up from what i know about the show. I'm not making an attempt to attack your theory I'm just going to be going over some of your material and explaining why I beleive the said material is incorrect. starting with the beginning. although there isn't much known about this mysterious unicorn, it is known that she is the personal student to Star Swirl The Bearded and helped him to forge the Elements Of Harmony into gems that could be used as weapons. They crafted them from the Tree of Harmony which said tree is made known of in the fourth and fifth seasons. Celestia did learn from him but so did many others. Celestia according to the show, is roughly over 1100 years old. something that is made mention about her is that unlike Cadence and Twilight who ascended to alicornhood, Celestia and Luna were Born Alicorns. i say this in part from my own research and a fan theory video that goes over a few topics about them. the video even goes as far as to bring in a conversation held between Lauren Faust and Meghan McCarthy about the origins of Cadence and how she was a Pegasus before her ascension. i will put a link at the end when im done, its got some great material and i suggest anyone to take a look. also in the hearths warming eve episode, it said that three individual kingdoms each ruled by the respective races of ponies existed before the founding of Equestria and the founding of it was because of a group effort from all three parties not Celestia. she and Luna just came in later and took over as the immortal rulers. you know, since they control and stabilize the orbit of the sun and moon so they revolve around their planet on a daily schedule. its kind of following that mantra that if someone who was immortal and possessed great powers were to reveal themselves to a primitive race they would be comparable to gods or goddesses in their case. the reason twilight is playing Clover is because as clover was the adviser to princess platinum of the unicorn tribe, Twilight is the student and adviser to Princess Celestia. they both serve under their leaders. this is a time when Celestia wasn't even recognized as a leader yet probably because she wasn't fully grown at the time in her skills or physically. plus the reason why clover was so powerful was because she was personally trained by the unicorn who invented over 200 spells so that is a pretty powerful teacher. because its common that even with important figures, over time some information about them can be changed based on the regime of the countries leader or leaders at the time. remember the war that happened when Nightmare Moon took over Luna. history has shown that evil people will go and burn books or documents on a whim because they feel it goes against their reign as well as insights rebellion. Nightmare Moon was in the process of trying to over throw Celestia and her rule so there is a possibility that like the Nazi's, when she would invade and take over a territory or land belonging to Celestia's empire, that she would immediately burn any books pertaining to Celestia and her victories. so its possible that by doing that they could have removed most of the information pertaining to Clover The Clever in the process. there is truth the old saying, "history is written by the victors and any that is lost in the process is gone forever." i believe the reason why the sisters knew him personally but were not in the hearths warming eve episode is as follows. First, as i said earlier, the events of the Hearths Warming Eve Episode takes place before the sisters came to power. second, Star Swirl The Bearded Died lived a long time. he was never killed and they never made mention that he had fallen in battle so the only likely scenario is to assume he died of old age. now according to the show itself, Granny Smith is well over a hundred years old due to the fact that earth ponies have long lasting longevity. based on this we can accurately conclude that the unicorns could live just as long if not longer using magic. Magic is an all powerful force in their world after all that Star Swirl wielded very effectively. He most likely lived long enough to be in a position to train the sisters before he past away. I agree, it does say that the rotations of the sun and moon were in fact controlled by the unicorns. that however was before Celestia stepped in and took over the job and later the title of princess of Equestria. the unicorns were being weakened by the spell and since its a children show they would leave out any concept of death. that does not mean that it doesn't happen even in a world full of talking technicolor ponies. no unicorn was ever meant to take on the job of raising the sun and moon alone and thats when they figured out a way around this. they formed a large group of spellcasters and combining their magics were able to perform the task as a normal function for a time mind you. real science also takes a unique role in their world as twilight is a scholar, a chemist, astronomer, and biologist. based on those results, its likely to assume that their solar system would follow similar physics as our own except with one regard. the orbits of the planet that they are on as well as their moon is out of whack because of weak gravitational pulls. so to compensate for the lack of proper orbit the unicorns used magic to make up for the differences and everything went on as normal. until one day when the unicorns could no longer perform the daunting task and the stress from doing that daily finally took its tole. unicorns started dying, and it just so happens that Celestia showed up and stopped them before taking on the task herself and thats how she got her Cutie Mark of the sun. at the end of it all, you have a pretty good theory here and i commend you on coming up with some pretty interesting questions. i hope that i may have been informative as well as helpful in answering your questions. thank you for taking your time to read this and may the magic of friendship be all our guides in our individual endeavors.