Mercury Sun Walkers

The sun is always just about to rise. Mercury rotates so slowly that you can walk fast enough over its rocky surface to stay ahead of the dawn; and so many people do. Many have made this a way of life. They walk roughly westward, staying always ahead of the stupendous day. Some of them hurry from location to location, pausing to look in cracks they earlier inoculated with bioleaching metallophytes, quickly scraping free any accumulated residues of gold or tungsten or uranium. But most of them...

 Evolving Levels of Thought

Gradually, at various points in our childhoods, we discover different forms of conviction. There’s the rock-hard certainty of personal experience (“I put my finger in the fire and it hurt,”), which is probably the earliest kind we learn. Then there’s the logically convincing, which we probably come to first through maths, in the context of Pythagoras’s theorem or something similar, and which, if we first encounter it at exactly the right moment, bursts on our minds like sunrise with...