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.