Saturday, August 23, 2014

PLANETS - Wanderers - until 3000 years ago



At a glance "wanderer " might be a good word. Venus sitting on Jupiter with the moon off to Taurus

Four days pass; Mercury makes an appearance

Next Moon is rising, Venus nowhere near Jupiter. 


But take another look
Jupiter is still in Cancer; can this be called wandering?
And the moon, the sun, and the planets are all along a line 
there's Leo, Cancer, Gemini, Taurus, the constellations of the Ecliptic. 

The Planets walk this line, in the same direction, at speeds related to their distance from the sun. 
Is this movement straying, or erratic, ie wandering? The line with its revealing name  of "The Ecliptic" turns out to be a series circles/ellipses, with the sun at a centre, viewed from the edge, just as a coin viewed edge-on is a line. 
Further, the circular orbits so often taught, are a view never seen from earth! 

Phasing out "dial-up" phones started about 40 years ago, but we still "dial a number". 

Planets only wandered until the patterns in their movements were explained. If students are only taught that planets wander, the lesson is 3000 years out of date.