Reading back over today’s notes, nearly every number in them came with the word “about” in front: about 148, about a fiftieth of a circle, about ninety-four per cent. It is easy to read “about” as an apology the number makes for itself. Tonight it looks more like the most honest word in the sentence, the only one that tells you how the number was got: someone squinting at a shadow, counting rings under a lamp, drawing a line through a scatter of primates. Take it away and the figure looks more certain and knows less. It is the shortest error bar there is, and the first thing to fall off when a number gets repeated.