Tags : Science Fiction

Short days—that’s what I wanted. The days in Jasper’s world should be an hour long. How is the topic of this post and the previous one. Why is another story. The previous post described the physics and writerly problems with a quickly-spinning planet. This one describes how Ard’s Girdle of The Gem Merchant’s Son and the godlands of the Clanmarks series came to be.

If the world can’t spin quickly, and ‘just magic’ is too facile, then I needed something to cast periodic shade—sunshades to cause eclipses. I’ll start with the effect I wanted, then work backwards to the cause. Here’s how I describe the effect in the Gem Merchant’s Son:

The day would be a scorcher, and the hourly eclipses welcome. …

At the eastern edge of the world, one of the twelve vast, invisible shield-plates of Ard’s Girdle, rising faster than the sun did, began to nibble into its lower rim. A minute later, the sunlight dimmed and the …

Short days–that’s what I wanted. Jasper’s world should have days about one hour long. How is the topic of this post and the next. Why is another story.

What’s hard about short days, you ask? The Gem Merchant’s Son is a fantasy. I could have said “let the days be one hour long” and be done with it. But I’ve never been a fan of ‘just magic’; I like there to be a system to it, even a science to it. Both The Gem Merchant’s Son and the Clanmarks series, which are set in the same world, are as much SF as F, and I like my SF hard as old cheese.

My first try: “Let Jasper’s world spin very fast.” Then the days would be short and consistent with the physics we know. But problems, problems.

The first problem: the Earth is not a solid ball; it is viscous, like plasticine. That’s more or less true for any planet. When it spins, it deforms, becomes flattened. Since Earth does spin once in 24 hours, its shape …