Answer:
Earth's revolution
<h2>How do we know that the earth orbits the sun?</h2>
If you study the stars and know where all the planets on the solar system are, you will notice that those stars alternate their motion in the sky, which means they do not orbit the Earth. In fact, the word "planet" originally means tricky star, suggesting that those "stars" did not behave like other normal stars.
The theory of universal gravity cannot be denied, since we are able to send satellites to outer space and have them orbit our plant. In fact, we are able to derive equations to figure out how fast the satellite need to orbit around the earth in relation to how high above the surface of the earth it is. The same mathematics that derived said information had also been used to derive the geosynchronous height from the Earth, which is the height at which a satellite orbiting the Earth, with the necessary speed to stay in circular orbit (not elliptical orbit), matches the Earth's rotation about its axis. Geosynchronous satellites are used for T.V. broadcasting and many other applications.
The formula for universal gravitation is GMm/r2, which means that the force of gravity on an object by another object are proportional to the masses of both objects, and inversely proportional to the square of the distance between them, and this proportion is multiplied by a constant G. It makes greater sense that the Earth revolves around the Sun, and not the other way around, because the mass of the Earth is way too small to apply a force strong enough to create a large enough acceleration on the sun to keep it in orbit around the Earth. If the Earth had enough mass to cause that huge of a gravitational force, then the moon will not remain in orbit around the Earth, but will fall closer the Earth and hit the Earth.
<h2 /><h2>What is the revolution of a planet?</h2>
The process through which a planet, let's say the earth, revolves around a huge mass that is significantly larger than the planet, such as the sun or any star. And the gravity between the two bodies is what causes this process to occur.
