Making Space for Sailing: from Galileo to Galileo, Jeremy Batch

Within days of turning his homemade telescopes towards Jupiter, Galileo Galilei made a discovery which would allow James Cook, 160 years later, to fix his position along the coast of Australia to an accuracy of 2.5 nautical miles, provided he stood on Australia.

Cook had taken the Endeavour to the South Pacific using Almanacs just published by the Royal Observatory at Greenwich, after nearly 100 years of work (what were they doing up there?) and a little help from the French. He only had tables for the first two years of the voyage (the rest he had to work out himself) and he learned to use the new-fangled methods and equipment while underway, like many a CA member.

But the official purpose of the expedition was to observe, from Tahiti, the transit of Venus across the Sun to help calculate the size of our solar system which, another two centuries later, we would begin to fill with robot spacecraft. These would allow us to send messages to the other side of the Earth, find our way to Pluto and Tesco, predict the weather, get rescued at sea, make minor adjustments to Cook’s charts and spy on the French.

Plus: how the ancient Greeks built an analogue computer and how Buzz Aldrin, three years before he walked on the Moon, saved the Gemini XII mission with a sextant, slide rule and tables.

Date: Wednesday 5 February

Time: Lectures and talks start promptly at 1900 hrs

Place: CA House

Booking: To book places on any lecture, and to indicate whether you’ll be ordering food, click on [Book Events Online]. Please pay on the door as usual. Any problems with the booking system, call or email Jeremy on 020 7537 2828/reception@theca.org.uk. Tickets are: £4 for members and £7 for non-members. Season tickets are available at £20 for the seven lectures from 5 February to 18 March. Please note that the season ticket price excludes the Hanson Lecture which must be booked separately.