The Earth rotates faster at the equator than the poles. The Earth is wider at the equator, making a complete 24-hour rotation at about 1600 kilometers per hour. Meanwhile, the Earth rotates slower at the north and south poles, traveling at about 0.00008 kilometers per hour.
You may ask, why do people living near the equator are not thrown off to space when our Earth travels much faster in their place? There are a lot of factors to consider why this is so. We got to look at the Coriolis effect, the centrifugal force, and the Earth’s gravity. Let us look at them one by one.
Coriolis Effect
The Coriolis effect is a term used to observe a moving body’s acceleration due to its rotation. It makes things that travel long distances (such as planes and winds) appear to move at a curve following the Earth’s direction. There is a simple reason for this – objects in different parts of the Earth move at different speeds.
Think about this: we want to measure the distance we need to travel fully and encircle a particular place. We also knew that the Earth is wider at the equator. Therefore, if we are at the north pole, it would take less distance to complete traveling around. However, if we are standing at the equator, say in Ecuador, it would take a lot of further travel towards the west and return via east.
This difference in the travel time causes the Coriolis effect. Another example: let us pretend you are somewhere at the equator, and you want to throw a ball to your friend in North America. If you precisely threw the ball in the straight line, the ball will land to your friend’s right because he is moving slower. Now, if you are to throw the same ball to your friend in Australia, this time, the ball will land to his left. The same is true of how winds move.
The Coriolis effect is responsible for why winds deflect at the Northern hemisphere’s right and the Southern hemisphere’s left. It is strongest near the poles and weakest at the equator.
Centrifugal Forces
Centrifugal force is the effect causing an object to move in a curve path to be pushed away from the center. To illustrate this, imagine you are driving a car, and you made a sharp turn towards the right. Where do you think your body will move? If you answered left, you are right! Centrifugal force causes you to move away from the center (that is, the corner of the street where you made the sharp turn).
However, the centrifugal force is not a real force but is an effect of inertia. Inertia is the tendency of an object to remain at rest or in motion along the same path unless an external force act upon it. When you drive, your body is used to moving on the same straight path. However, when you suddenly took a turn, inertia resisted the change in velocity, making you move towards the left to balance it.
The Earth is also moving at a curve path, but why is the centrifugal force not acting upon it?
Gravity
Gravity is the force that draws objects towards its center. It is the answer to why we are not moving towards the east, opposite the Earth’s direction. It is also responsible for why we are not thrown outside the planet.
Regardless of whether the equator or the northern and southern hemisphere moves at different speeds, nothing will be sent blasting off. Gravity holds everything down. If the centrifugal force were stronger than the force of gravity, everything would be thrown into space.
If centrifugal force was also stronger than gravity, then planets were unlikely to be formed. A stronger centrifugal force would cause the Earth to tear itself apart. It would rip out its surface and become smaller because gravity can no longer hold on to it while it spins.
Gravity will also not throw people at the equator towards space! The Earth would have spun 25 times faster (that is 40,000 kilometers per hour on the equator) to throw everything out.
Therefore, unless the centrifugal force is stronger or the Earth spins 25 times faster, no force could ever throw humans into the vast galaxy.