Why is the sensation of Earth’s rotation not perceptible to us?

Earth moves around the sun at 67,000 mph and makes a full rotation once every 24 hours. So why can’t we feel the Earth’s rotation?

There are two primary explanations for why we don’t feel the rotation of the Earth. Firstly, Earth’s rotation is incredibly smooth. Just like when you’re in a car traveling at a constant speed on the highway, you feel stationary because there is no change in motion. This concept of relative motion, rather than absolute motion, was emphasized by scientists like Newton and Galileo. They demonstrated that whether you’re on a ship sailing on calm waters or docked at a port, you won’t notice any difference according to the laws of physics.

Secondly, everything on Earth, including our atmosphere, is moving along with us. Just like when you roll down a car window on the highway and feel the wind, the air molecules outside the car are hitting you. However, when the car window is up, the air moves with you, and you don’t feel the wind. Similarly, our planet’s atmosphere moves at the same speed as we do, making it appear stationary relative to us.

Additionally, gravity plays a significant role. The force of gravity that keeps us grounded is much stronger than the force that would propel us outward due to Earth’s rotation. Therefore, we remain firmly attached to the Earth and don’t experience the sensation of being pulled outward.

Centripetal acceleration, also known as the sensation of being pulled outward on a carnival ride or while a car is doing doughnuts, is caused by the feeling of inertia. According to Gbur, when you’re in a car, your body naturally wants to continue moving in a straight line, but the car’s circular motion tries to pull you in a different direction.

Similarly, the Earth’s rotation creates an outward pull on everything, but the force of gravity that keeps objects stuck to the ground is stronger and overpowers this pull.

Gbur explains that the acceleration due to gravity on the Earth’s surface is approximately 9.8 m/s^2. The reduction in this acceleration caused by the Earth’s rotation at the equator, where objects are moving the fastest, is around 0.03 m/s^2. Although this reduction is measurable, it is extremely small compared to the force of gravity itself, so we do not perceive its effects.

This article is republished from livescience under a Creative Commons license. Read the original article.