ARCHIVE.

Everyone learns that ice is slippery because a thin skin of water coats it. Why that skin forms is a different matter, and the argument has run for nearly two centuries without a winner.

A micromort is a one-in-a-million chance of dying, packaged as a unit. Giving tiny risks a shared scale lets them be compared and, within limits, added up. And the limits turn out to be the interesting part.

Two spoons sit in the same drawer for a week and end up at exactly the same temperature, yet the metal one feels colder in your hand. Your skin isn't measuring the spoon. It's reporting the temperature of the handshake between you.

Flick water onto a warm pan and it hisses away in seconds. Flick it onto a much hotter one and it beads up and skates around for far longer. Past a certain point, more heat makes the drop last longer, because it's riding on a cushion of its own vapour.

A coffee spill doesn't dry to an even brown blot. It dries to a dark rim around a pale middle, because the drop's edge gets stuck and a hidden current spends the whole drying time carrying the coffee outwards.

Inside many of your cells are tiny structures that carry their own DNA, separate from the DNA in the cell's nucleus. They are the descendants of bacteria that were swallowed more than a billion years ago, never got digested, and never left.