On Wed, Jun 6, 2012 at 6:09 AM, Jim Lux <jim...@earthlink.net> wrote:
> Does anyone know more details how this is done? Is the state-of-the-art >> at the millisecond level? microsecond? nanosecond? >> > I'm thinking "few milliseconds is the best we can do, ever. Especially from the ground. By 1874 thy had decent clocks and even photography and good telescopes. The problem is that the exact time is not well defined visually. The infamous "black drop" effect prevents accurate timing. This is where Venus and the Sun appear to be moving closer at a slow rate and then as they get closer, venus "jumps". does anyone have a reference to the math and process used to measure distance from earth to sun using transit of venus? I think it is as simple as a "similar triangles" geometry problem. There was a recent article on this in Sky and Telescope. Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.