Sometimes some strange new germ of a story idea occurs to me, and I feel fairly certain I won't actually write that story. In such events, I think maybe the best thing to do is to publish the idea on this here blog thingy and maybe someday, someone else might decide it's an interesting idea.
I was thinking about the interior of the Earth. The Earth's core has a solid inner part, and liquid outer part. The boundary is a kind of surface of crystallization, expanding gradually outward at a rate of a millimeter a year or some such tiny amount, as the Earth's core cools. Not that it's cool, in there. The liquid is mostly iron and nickel, with dissolved lighter elements: sulfur, calcium, oxygen. The idea that oxygen is included got me to wondering: could some type of chemo/thermophilic lifeform emerge in such an environment?
It wouldn't be carbon-based, or even silicon-based. Iron-based, maybe? Is that chemically plausible? I don't know enough about it. But I also thought back to a book, Dragon's Egg, by physicist Robert L. Forward. It's science fiction, but it's quite "hard" science fiction, in that he's worked out the physics of the emergence of intelligent life on the surface of neutron star. It's a rather interesting book.
Anyway, couldn't a similar treatment be applied to some core-dwelling lifeform, evolving intelligence over a billion years or so down there in the deeps, in a soup of liquid metal. And maybe their main sensory systems are based on magnetism (which makes sense in an iron-based environment, maybe). And these creatures start exploring upwards… building rivers of "breathable" molten iron upwards through their sky of stone. Until they arrive on our surface and meet us – dwellers of the outermost atmosphere, frozen beings made of puffs of something less than air, from their perspective.
What kind of close encounter might that be?
[daily log: walking, 7.5km]