In his charming (but not always accurate) book "Light and Colour in the Open Air" (Bell, 1959), which was earlier published as a Dover paperback, M. Minnaert mentioned several multiple sightings of the green flash. He referred to Byrd's expedition to the South Pole when the green flash could be observed for 35 minutes. The ideal location for measuring the earth's radius would presumably be the North or South Pole, close to an equinox. John Lynes
--- On Mon, 2/3/09, Frank Evans <frankev...@zooplankton.co.uk> wrote: > Greetings, fellow dialists, > Long ago, in the days of North Atlantic weather ships, a > meteorologist > told me that he had managed to see the green flash at > sunset twice at > one setting. He did this first from the main deck of the > weather ship > and then scampered up to the upper deck to see it again. I > imagine that > the green flash presents a more precise instant of time > than the > terminator and hence it would be possible to measure the > precise > interval between the two events and also the precise > distance between > the decks. A bit difficult to organise, though, although > the conditions > for a possible green flash are well known. > Frank 55N 1W --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
