Why does not the Earth fall?

The law of universal gravitation tells us thatall bodies are in each other in a gravitational interaction, that is, they are mutually attracted to each other. And the force with which one body attracts another is directly proportional to the mass of this body. If the masses of the bodies are not comparable to each other, and one body is hundreds or thousands of times heavier than the other, the heavier body will completely attract the lung to itself.

Every day we see how an object falls to the ground. This planet Earth as a physical body attracts to itself a thing that has lost support.

But in fact the Earth itself is located near an even heavier heavenly body - the Sun. The mass of the Sun is 333,000 more than the mass of the Earth, so why does not the Earth fall on the Sun?

The thing is that the force with which the Earth is attracted to the Sun is balanced by a centrifugal force acting on the Earth as it moves around the circumference of the Sun.

What is centrifugal force?

Centrifugal force is a force thatIt affects the bodies as they rotate around the circumference. In this case, the rotating body tends to fly away from the center of this circle with constant acceleration. Centrifugal acceleration depends on the speed of rotation of the body. The higher the speed, the greater the acceleration.

A case in point. We take a ball suspended on a string. In a quiet state, the ball under the influence of the gravitational force of the Earth hangs on the rope in a direction vertically downward. This is the force of gravity of the Earth acting on it. It is not only the tension of the thread that does not allow it to fall completely to the ground.

If the ball is untwisted in the horizontal planewith a great speed, centrifugal force will begin to act on it. The ball will no longer hang vertically down, but will rotate in the horizontal plane and seem to move away from the center of rotation. You can even physically feel how the rotating ball stretches the rope. A keeps the ball near the center of rotation the same thread tension force. If the ball is untwisted to such a speed that the centrifugal force becomes greater than the tension of the thread, the thread will break and the ball fly away in a straight line perpendicular to the radius of its rotation. But at the same time it will not rotate further, the centrifugal force will disappear and, after flying a little, the ball will fall to the ground (you know why).

Centrifugal force of Earth's rotation

An analogous interaction is also observed whenthe motion of the Earth around the Sun. The centrifugal force acting on the Earth as it rotates removes it from the center of rotation (that is, from the Sun). But if the Earth stops rotating around the Sun and stops, the Sun will draw it to itself.

On the other hand, the force of attraction of the Sunbalances the centrifugal force of the Earth's rotation. The sun attracts the Earth, the Earth can not fly away from the center of its rotation and moves in a constant orbit around the Sun. But if the speed of the Earth's rotation increases many times, and the centrifugal force exceeds the force of the Sun's attraction, the Earth will fly to outer space and fly for a while like a comet until it falls under the attraction of another body with an even greater mass.

Likewise, the Moon does not fall to the Earth (this is in the article Why the Moon does not fall to Earth), but meteorites fall (Why stars fall).

Another interesting question: why does the Earth revolve around the Sun? Read about this in the article Why the Earth rotates.