Take a per­fect sphere of some ide­al­ized mate­r­ial, col­ored black, and heat it up. It’ll start to radi­ate in the infrared, heat. Add more energy to it, and even­tu­ally it’ll glow in col­ors you can see: dull red first, then orange, yel­low. Heat it long enough and it’ll glow bril­liant blue, like the hottest and youngest stars there are.

That’s how stars work, in the­ory. In prin­ci­ple gases and dust and maybe inter­stel­lar inva­sion fleets get in the way, block­ing cer­tain lines as they absorb spe­cific spec­tra of light.

But this isn’t an astron­omy les­son, this is a fable. About how my father died, and yours too, prob­a­bly. There aren’t many of us left since Wish­ing Day.

The magic dragon woke in his cave at the mountain’s sum­mit, and saw X, the man who’d climbed nearly into space just to make his wish.

“I wish,” X said, not really think­ing it through, “that sun­light was diamonds.”

Ten tril­lion dia­monds flew out into space, most of them miss­ing Earth by hun­dreds or mil­lions of miles.

Mil­lions just fell from the sky.