Gravity is the force that keeps us from falling off the Earth. The Sun's gravity is about 29.7 times stronger than Earth's, which is how it keeps our planet, and the other planets of our solar system, orbiting around themselves. Gravity is the reason the Sun itself formed 4.5 billion years ago. Gravity allows every object with mass to have a gravitational pull towards each other. For example, your pet, the Sun, and the exoplanet Arion — which is 238 light-years away — all have a gravitational pull towards you just like how you have a gravitational pull towards them.
Back in the 1600s, an apple fell on Sir Isaac Newton’s head, sparking a series of enlightenments about the motion of falling objects. That is probably not how he discovered gravity, but he ended up defining it as the principle that two particles attract each other with forces proportional to the product of their masses divided by the square of the distance between them. His theory remained uncontested for 300 years until the 1900s when Albert Einstein argued that gravity is a curvature of space-time caused by the presence of energy or matter. According to his theory, an object creates a gravitational field by distorting the geometry of the space-time that is surrounding it. His theory was proven in 1919, 3 years after it was first published.
But what would happen if gravity suddenly disappeared? Would we be able to continue living as before — the only difference being that everyone is casually floating in the air? The answer obviously no. If gravity were to be somehow turned off, here is what would happen. The canals in our inner ears are filled with a special fluid that sends signals to our membranes to help us interpret sensory information and create a sense of balance in our minds. Since we all would be levitating, the signals would be thrown off by the constant movement and cause us to feel extremely dizzy and nauseous. Do you know the feeling you get when you have just gotten off a roller coaster ride and, even though you had fun, you are about to throw up? Imagine that feeling, but it does not go away no matter what you do. Our body's musculature and bone structure have evolved to be able to move freely under the influence of Earth's gravity, therefore without any gravitational force, our blood would be rerouted, flowing from the legs to the head. Our legs would become very thin and our heads would swell up. To put it bluntly, we would be unable to take care of ourselves, let alone take care of another human-being, which would eventually lead to the extinction of the human race. However, it is important to mention that all of the hypothetical scenarios mentioned above can only take place if gravity was turned off for humans.
If gravity were to disappear for the entire universe, all hell would break loose. The atmosphere would begin to ascend into space along with all air and water, causing the air pressure to drop to zero in an instant. A sudden drop in air pressure would cause our eardrums to rupture. Since there would be zero oxygen on Earth, H2O would turn into H2, causing water to become hydrogen gas. Water makes up more than 70% of a cell’s total mass, which means every living cell would fulminate. Unrestraint by a gravitational force, all the entities in space would start moving uncontrollably eventually leading to catastrophic collisions in the universe.
But what if Earth’s gravity doubled? Our lungs would be under fatal stress causing us to have trouble breathing. The same stress would also apply to our hearts, creating a spike in our blood pressure. Our weight would double, so actions such as walking, running, climbing stairs, jumping, etc. would become extremely tiring. Buildings all around the world would collapse under their weight, planes would not be able to fly, and even if they did, they would crush almost instantly. Most importantly, Earth’s core would collapse in on itself, meaning none of us would survive to experience the other consequences.
We fail to notice the constant influence of Newton's law of universal gravitation on us. Being able to explain the things we have been trying to uncover the logic behind from the moment we first gained consciousness is an experience laced with excitement. These laws have always existed, and will continue to exist. Let’s just hope that the universe does not wake up one day and decide to prank us all by making them disappear.
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Feeling off-balance? the problem might be in your ears. Keck Medicine of USC. (2022, May 26). Retrieved September 9, 2022, from https://www.keckmedicine.org/blog/feeling-off-balance-the-problem-might-be-in-your-ears/
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