Why does the Moon follow us every were we go?
Sky watchers from the beginning of time have observed the presence of the Sun and Moon no matter where they travel. Early astronomers’ explanation of this phenomenon was that Earth is flat and has a dome over it. The dome acted as a background for all celestial bodies, which are the natural things seen in the sky including the Moon, the Sun, and stars. The celestial bodies moved from one side of the dome to another, much like actors entering a stage from one side and exiting on the other side. You can see actors on a stage from any seat in the theater, so the Sun and Moon could be seen from any location on Earth.
The previous explanation sounds rather dumb to us now, but that is because we know so much about our universe. Never the less, I do find it fun to dream up imaginary explanation for the things we see. For example, imagine two very long invisible strings, one attached to the Moon and the other attached to the Sun. As you move the two celestial bodies must follow, much like helium balloons attached to strings. While this is a fun idea, it obviously is not true. Actually, the idea that the Sun or Moon is following you isn’t true, but since you see it and it seems to be true it is called an illusion.
The illusion that the Sun or Moon is following you is due to their great distances from Earth. The Sun is about 93 million miles from Earth and the Moon is 238,000 miles away. No matter where you move on Earth, there is so little change in your distance from the Sun or Moon that you don’t notice it. Because of this, you never move past or away from these celestial bodies.
Discover for Yourself
Distant objects seem to follow you, while objects near-by move out of view.
Outdoors, pick out a distant tree.
- Walk toward the tree and notice that things you pass, drop out of view but the tree remains directly in front of you.
- Turn right and walk a short distance. Again, notice that some things drop out of view. The tree is still in view, but it is on your left side instead of being straight in front of you. Has the tree moved? No, you turned so that your left side faces it.
- Turn right again and walk a short distance. As before things fall out of view and while the Tree is not visible you can still see it if you look behind you. Has the tree moved? No, you turned away from it.
- Turn right again and walk a short distance. Again, some things fall out of view. The tree is now in view on your right side. Did the tree move? No, you again changed your direction so your right side faces the tree.
|Astronomy for Every Kid: 101 Easy Experiment That Really Work|