If the Earth Rotates Why Don't We Get Dizzy ... and other Interesting Questions
Let's start with the question of this section. We never get dizzy when the Earth rotates. Why Not? The answer is that we are spinning at the same rate that the Earth is spinning—relative to the speed of the Earth, the speed that we exhibit is zero (0).
That leads to another question. Why don't we, and all other objects, just spin off the Earth and fly into space? The answer is that there are are two forces that are in play here - gravity in the form of a centripetal force and the inertia of the objects that are spinning.
Explanation of the Image: The vector (or the magnitude and direction of an object ) represents the relationship for uniform circular motion. V is Velocity, r is radius. The vector Ω represents the rotation and is perpendicular to the plane of the orbit. So the velocity is given by a vector formula as V = Ω x r. Here is what that means.
Imagine that you tie a ball to a string, and you start spinning it around. One force wants to break away from the center and go off on its own; and the other is the force that keeps the ball attached to the center, which in this case is the string. If you let go of the string, the ball flies out.
Now because you are spinning around on the Earth, a similar force exists that wants to push you off into space. But, like the ball on the string, that inertial force is not very strong, and it is totally overwhelmed by the force of gravity (the string) that is keeping you attached to the Earth. The force that wants to throw you into space is only 0.3% of the force of gravity, whereas the centripetal force is 99.7%. So, people and things are going to stay put. They will not spin off into space.