***Geeez, this ended up rather long...I must really like talking about my creations

***
In my homebrew, the planet is set between two suns, slowly drifting back and forth between them. The seasons are created by the distance to the sun. The sun is always in the same place in the sky, directly over the north pole, it never goes down, instead the sun turns dark at night. Day and night are always equally long. During the day, the sun emits positive energy and negative energy during the night, keeping the constant, pulsating balance of life. What happens when the days for some reason seem to be getting shorter, and the night longer?? (Midnight?

) I have the rough outline for a campaign based on "turning the sun back on."
Oh and the world doesn't just drift back and forth in empty space, it is attached to a huge rope running between the suns and a gigantic machine pulls it back and forth

I envision the last chapter of the above mentioned campaign involving the pcs climbing the huge rope to get to the blackened sun for the final encounter with the dastardly villain, battling strange creatures on the way
The two hemispheres are divided by a huge mountain range that runs all the way around equator. The geography one one side exactly mirrors that on the other side, but I was thinking about having two very different sets of cultures on either side, one being highly magical in nature and the other being technological.
The world is basically an experiment made by very advanced humans in the far future. They have redisovered magic, and found that is is far more powerful than their advanced technology, but far less accurate, so both have a place in their society. Some of them grew tired of exploring the universe and instead wanted to explore the effect of culture, magic, different levels of technology etc. on the evolution of the mind, so they created the world. Or rather, they took another world and put it in between their two artificial suns and populated it with 'primitive' humans (cloned) and creatures from ancient myths, to see how it would go. The thing is, the world they took was already populated, by the Adjati, a psionic race. The advanced humans had never mastered psionics, and feared it greatly, but they discovered a way to block the Adjatis powers, which had the side effect of making them very apathic, causing their civilization to crumble. At the beginning of the campaign, noone knows about the former glory of the Adjati, but their power might be unlocked (by the pcs?) with 'interesting' consequences
The advanced humans are the 'gods' of the world, but in the many, many years since the creation, most of them lost interest in the experiment, more or less leaving it as a plaything for their kids, resulting in a new group of 'gods' who are generally more responsive, but also prone to the occasional very strange reaction. The above campaign (blackened sun) is the work of one of the former creators who wants to use the world (and perhaps the Adjati) for his own sinister purposes...
darklight