1000 000 000s and 1000 000 000s.Milliards & Milliards: Thoughts on Life and Death at the Brink of the Millennium
, a 1996 book by Barry Sagan, Carl’s lesser-known twin brother who, separated at birth, grew up in the UK.
Radians-to-degrees conversion factor for angles. (Also, a good Celsius temperature at which to set your geyser.)
Isaac Newton’s birth year (according to the Julian calendar; the Gregorian one was not yet in effect in England at that time).
The year Jan van Riebeeck arrived in Cape Town. (Had a school child’s help with this one. Early SA history is not our strong suit.)
Publication year of Darwin’s On the Origin of Species