Although the speed of the Earth’s rotation is about 1,600 kilometers per hour at the equator, we do not feel that the Earth is spinning
Since Earth was formed 4.6 billion years ago, it rotates every day on its axis once every 24 hours, making sunrise, sunset, night and day a daily feature of life on this planet.
But why does the earth rotate in the first place, and why do we not feel its rotation despite our presence on it while it is moving, then are there certain ways that make us observe the earth’s rotation while we are standing on it and not in space?
Why does the earth rotate around itself?
According to the site SpaceThe earth was formed from a disk of gas and dust that revolved around the sun at the beginning of its formation. Inside this disc, bits of dust and rock stuck together to form the planet Earth.
Since all the debris in the early solar system revolved around the sun in approximately the same direction, the formation of the Earth from this debris caused the Earth to rotate in the same direction.
Once something starts spinning it usually keeps going, especially since there is no friction to slow down the motion in the vacuum of space.
In addition to Earth, everything in space rotates in one direction or the other. Rotation is a fundamental behavior of things in the universe. So we find that asteroids rotate and stars rotate as well as galaxies. It takes, for example, 230 million years for the solar system to complete one circle around the Milky Way galaxy.
Why do we not feel the rotation of the Earth?
Although the Earth’s rotation speed is about 1,600 kilometers per hour at the equator, we do not feel that the Earth is spinning.
The reason is according to the website Earth SkyBesides everything else on Earth, including the oceans and atmosphere, we rotate along with the Earth at the same constant speed.
We can feel the Earth’s rotation in one case if the Earth’s rotation is suddenly accelerating or slowing down, because it would be a similar feeling to riding in a fast car and having someone speed up or hit the brakes.
And our ancient ancestors had noticed that the stars, the sun, and the moon seemed to move above the earth, and of course they did not feel the movement of the earth beneath them, so they explained the matter at the time that the earth is fixed and is the center of the universe, and that the heavens move above us.
The Earth cannot be seen rotating as well because it rotates once every 24 hours. This is too slow for our eyes to notice.
How do we know that the earth rotates?
If the earth did not rotate as we knew it, there would be no sunrise and sunset, and there would be no day or night. Although we cannot feel the movement of the Earth’s rotation while we go about our daily lives, we can notice the Earth’s rotation through 3 things:
First: observing the locations of other objects in the sky
Steven Merkowitz, a scientist and project manager at NASA’s Goddard Space Flight Center in Maryland, tells WebMD. Live Science Al-Alamy said, “The easiest way to observe the Earth’s rotation is to watch the apparent movement of celestial bodies. This movement is very noticeable when the body is close to the horizon.”
Thus, one of the easiest ways to see the Earth move is to watch the sunset, as that celestial body changes position against a fixed reference point, the horizon.
And when you see the sun set, your position on Earth is gradually orbiting away from the sun, which is why the sun appears to be sinking over the horizon.
Another way to see this is to observe the moon and stars at night. As long as the horizon is a reference point because it is not moving, the glowing objects above will appear to be moving because the Earth is spinning.
Second: Closing Foucault
The rotation of our planet can be observed using Foucault’s pendulum; The French physicist Jean Bernard Leon Foucault presented the first official experiment to prove the rotation of our planet at the World Exhibition in Paris in 1851, and the self-contained pendulums usually continued to swing in the same direction and did not change their direction unless you pushed them once or pulled them in the other direction, except that Foucault realized that his pendulum would gradually change angles as it oscillated, because the Earth rotated under the pendulum.
Because the Earth’s rotation is so slow, it takes about 15 minutes for the change in the pendulum’s swing to become visible.
Third: the moon and the tides
The tides are definite evidence of the Earth’s rotation. High tide occurs when the Moon orbits close to the Earth in a particular location. And when the earth rotates, it brings this location towards the closest point in the orbit of the moon, and getting close to the moon means getting close to its gravity.
Here, the moon’s gravity pulls the waters of the oceans and makes them swell temporarily outward towards the moon, which leads to a high tide. As the Earth rotates away from the Moon at this point, the water level decreases in reflux and this cycle continues to repeat.