Which is true:

1. The earth revolves around the sun.

2. The sun revolves around the earth.

3. There is no revolution.

The earth revolves around the sun. because revolve means rotating while circling another object. The earth rotates and goes around the sun.

The Earth and sun both revolve around their common center of mass.

But since the sun is so humongously more massive than the Earth, their

common center of mass is deep inside the sun. So if you were watching

the whole thing from somewhere outside the solar system, you'd swear

that the sun is perfectly rock-steady, and the Earth is revolving around it.