I do not know anything about astronomy; but, I am curious about the sunset. Sitting on the porch in the late afternoon when the sun is going down, it appears to set in different locations. I see large changes over night, but it appears to be on top of my hill over the road then a few weeks later it appears to be in the middle of the field. Why? Is the sun moving or are we the ones moving?
We are the ones moving. What you see each day when you look at the Sun moving across the sky is the effect of the Earth rotating on its axis. Because the Earth spins on its axis, it looks like the Sun is moving across the sky.
But there's another effect at work that makes the Sun's apparent path different each day. The Earth is also revolving around the Sun, so each day of the year, the Earth is at a different point in its orbit. So because the Earth is facing the Sun at a different angle each day, the "path" the Sun makes in the sky will be different each day of the year.
In fact, the different paths that the Sun makes is what causes the seasons.
This is illustrated here.
This page was last updated June 28, 2015.