More About Rotation II
2. Equinoxes...
Imagine that you are the sun. (I know, pretty silly stretch, but, trust
me on this one.) Now, when there is an equinox, all parts of the Earth
get the same number of hours in the daylight: 12, right? The only way
for this to happen is if the Sun can see the tilt of the Earth's axis, and
there are 2 times when this can happen. The first time is when the Sun
sees the axis tilted to the right, and the other when it is to the
left.
Here's what I mean. This is what the Sun will see in the Spring:
And in the Autumn, imagine standing in the screen to look at the
animation on the other side, still from the Sun's point of view: the axis
would be tilted the other way, but it would still be going around the
axis in the same direction.
If it's still a little tough to grasp, the next mini-lessons will make it
a lot simpler.