The Physics Behind a Spinning Earth
Why don’t we feel it rotating?
I recently came across a meme that asserted that if the Earth really rotates, a helicopter would just hover in the atmosphere and wait for its destination to find it. While I assume the intention was mockery, it sparked a pool of questions from some of my colleagues who asked for a sound explanation.
It eventually boiled down to why we don’t feel the Earth spinning, if it really is.
It has been centuries now since we’ve moved past the geocentric (Earth as the centre) model of the universe to the heliocentric (Sun as the centre) model of the universe. It is not completely absurd that people asserted the Earth was static, while the sun and other heavenly bodies orbited around it. After all, none of us today could say they feel our blue dot rotating.
Despite the advancements in science, some people are incredulous to scientific findings (via scientific method) that go against our senses. So much so that an alternative of the scientific method, called Zetetic method (a method that advocates that sensory observations reign supreme), largely used by flat-earth theorists, has been propagated.
I find it utter folly for one to place so much trust in their senses to interpreting natural phenomena. Our senses are liable to illusions.
The image above is of my phone, and to a lot of my friends, this phone looked so transparent. Except it’s not. And if you, the reader, see it to be transparent, I have some bad news for you. Don’t place so much trust in your senses. The Zetetic method, sorry to say, is a bogus approach to science.
Allow me to start by giving a personal experience that may help consolidate the understanding of a spinning Earth.
When I played house as a Malawian child, I remember making braziers (locally known as mbaula) out of tin cans. With burning charcoal in the tin can, I would spin it vertically, the top end open. What I figured was, when the speed of my spinning was fast and constant, no piece of charcoal seemed to fall off or move out of place. While when my speed was slow and erratic, pieces would fall off.
I’ll not delve into the scientific evidence that the Earth is spinning. My goal is to tell how a spinning Earth is possible.
Physicists tell us that the Earth moves at a constant speed of 1600km/hr…and we’re on top of it. From the brazier analog above, we can postulate that as the Earth moves, we are moving at the same speed with it. It is the constancy of Earth’s speed that is giving us the illusion that it is static.
Newton’s first law of motion, which is the law of inertia, states that:
Imagine you’re a standing (or sitting if you like) passenger, enjoying your soda, on a bus that is travelling at a constant speed of 60km/hr. Then, suddenly, the driver steps on the breaks. What effect would it have on you? The breaks (a force inadvertently acting on you) would push you forward (setting you in motion), and the only way you’ll stop is if another bigger opposing force (whatever you’ll possibly crash into) acts on you. That’s how inertia works.
You’re never going to enjoy having your coffee on a bus that is not able to maintain a constant speed (or at least accelerating/decelerating gradually), more so on a bumpy road. Why do you think air hostesses are able to serve your champagne without making a mess when the plane is in motion?
How are you able to walk to the bathroom in a moving plane without a stagger in your walk? That’s the same way you’re walking on a surface of a spinning Earth right now.
In effect, the only way you’d feel the Earth moving is if it suddenly stopped moving or suddenly began moving at 3200km/hr.
Getting back to the first problem, physics has us understand that when the Earth rotates, so does its atmosphere. In turn, it’d be futile for our helicopter to wait for its destination, because the atmosphere it hovers in is moving along with the Earth.
