Saturday 20 June 2015

Why Icarus Eros and Venus?

Johannes Kepler published his laws of planetary motion around 1609. The Third Law relates the period
of an object to the size of its orbit, such that:
the square of the orbital period P is proportional to the cube of the mean distance a from the Sun (half the sum of greatest and smallest distances). In formula form
P2= k a3
with k some constant number, the same for all planets.

It was Edmund Halley who suggested transits of Venus could be used to determine the scale but the "black drop" made the timings imprecise. Sir Harald Spencer Jones suggested the asteroidEros,  might work. And
during the past couple of nights Icarus was also used, more to determine its shape than to determine the scale of the solar system.

That is it for tonight - spent the day in Barrie at Paddlefest, and have some good photos for some day! This evening while looking out on the calm lake a great blue heron flew in and landed on our dock so I took its picture also for a rainy day.

I am tired bcause I have been up the past 2 mornings around 4am to photograph the sunrises - I hoped that it might be aurora but realistically just beautiful painted sunrise dawns.  I'll post them soon?

Tonorrow is the Coldwater studio tour. Weather mixed outdoors, art mixed indoors. Probably will take the camera. Have a good Sunday/einen schönen Sonntag.


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