"Hi folks I'm not a nut or anything but I was wondering how gravity can hold something as immense as an ocean down but won't crush us? Can you explain it to me so I understand?" - Kevin
Hi Karl and thanks for the question.
Gravity is an ever-present force that governs the celestial dance of our universe. From the grandeur of galaxies down to the tiniest particles, it holds everything in its inexorable embrace. But how is it that gravity, capable of anchoring vast oceans and towering mountains to our planet, doesn't crush us or our surroundings?
To answer this question, we must embark on a journey into the enigmatic world of gravity, a fundamental force that underpins the very fabric of our existence.
First and foremost, it's essential to grasp that gravity is a force of attraction between any two objects with mass. The strength of this force is determined by the mass of the objects and the distance between them. So, whether it's a colossal mountain or a minuscule pebble, gravity affects everything with mass.
The Balance of Forces
Now, let's delve into the heart of the matter. When we ponder the Earth's colossal mass and its gravitational pull, it's natural to wonder why we aren't squished under its immense weight. The answer lies in the balance of forces.
Yes, gravity pulls objects towards each other, but this force doesn't escalate indefinitely. As objects get closer to the Earth's surface, gravity's pull increases. However, there's another force at play that prevents us from being crushed: the electromagnetic force.
At the atomic and molecular level, the electromagnetic force is what keeps matter stable and prevents it from collapsing. Think of atoms as tiny solar systems with a central nucleus (comprising protons and neutrons) and electrons orbiting around it. Electrons, endowed with a negative charge, repel each other due to their like charges.
This electromagnetic repulsion creates a stable structure within matter, whether it's a rock, a glass of water, or your own body. When you touch an object or stand on the ground, the electromagnetic forces between the atoms in your body and the atoms in the object or the Earth's surface counteract the gravitational force, creating a delicate equilibrium.
The Solidity of Matter
Matter, at its core, consists of particles with mass and the electromagnetic forces holding them together. This is why solid objects resist being crushed under gravity's influence. It's not that gravity isn't acting on us; it's that other fundamental forces, particularly the electromagnetic force, provide the structural integrity that keeps matter stable.
Scaling the Cosmic Stage
To put it in perspective, imagine an ant crawling on your skin. It doesn't get crushed by the gravitational force between it and your body. Similarly, the Earth's surface, composed of matter with its electromagnetic forces, resists the pull of gravity.
Now, when we look at objects like oceans and mountains, we see the cumulative effect of countless atoms and molecules working together. The electromagnetic forces between these particles prevent them from collapsing, even under the relentless pull of gravity.
Gravity is indeed a mighty force, capable of holding oceans, mountains, and celestial bodies firmly to Earth. However, the delicate balance of forces within matter, particularly the electromagnetic force, ensures that we, along with our surroundings, remain uncrushed. It's a testament to the intricate harmony of physical laws that govern our universe, allowing us to exist and thrive on this remarkable planet.
You’ve come this far…
Why not venture a little further into A.S.S. - our exclusive Australian Space Society.
And keep thrusting Australia into the deep unknown…