Hey there folks, As a forward: I'm trying to build a "high fantasy" universe in which to write stories, but within its historical timeline of events there are some cosmological happenings that I'd prefer to not just wave a wand at, so to speak. I'd like there to be at least SOME solid grounding in science so the world still retains some shred of believability. The planet I'm focused on developing has gone through an era where its axial rotation has been very slow. It's locked in an orbit where one side always faces the sun. During this time, sentient races have evolved and progressed on the planet. Now... that perpetual day/night environment is great for designing cool fantasy races from the extreme polarities, but... that's about where that dynamic's usefulness ends. The planet is way too static to hold much interest, what with no day/night change, seasons, etc... So finally, my questions: 1.) What kinds of physical cosmological events could occur that might speed up this planet's rotation so that it might at least have a more earth-like day/night cycle, without (here's the tricky part) killing off all sentient life on the planet? 2.) Is it possible that this event could happen on a time-scale in which the changes could be experienced in the length of... let's say maybe a century long window? So far my best guesses have been: - somehow pull the moon in closer to the planet or - have a massive comet/asteroid fly by incredibly close using its gravitational influence to speed it up and/or graze the planet with a "small", indirect impact Other than that, I got nothin'. Any help or suggestions would be immensely appreciated! Thanks!