Inertia and the universe

Static and kinetic inertia are among the fundamental driving forces of the universe

Let’s take a moment to learn some science.

Inertia (both static and kinetic) is a term in physics without which our existence would be impossible. Without it, there would be no water on Earth, no air, no emergence of life – not even the billions of life forms that evolved from microscopic unicellular organisms. Our planet constantly rotates on its axis and revolves around the sun, yet we don’t feel it. That’s because of inertia – specifically, kinetic inertia. It’s due to this inertia that when a moving bus suddenly stops, you lurch forward, and when a stationary bus suddenly starts moving, you fall backward.

Because of Earth’s gravitational force, everything stays attached to it and moves toward it. Even though the Earth is rotating, we don’t get flung into space. However, there are certain atoms or substances that defy Earth’s gravity. They try to escape and, when given the chance, they do. For example: hydrogen and helium. These elements don’t care about Earth’s gravitational pull – they drift off into space. Every year, Earth loses about 95,000 tons of hydrogen and 1,600 tons of helium. No need to worry – Earth has plenty of both. Losing 96,600 tons doesn’t make much of a difference. On the other hand, cosmic dust, comet debris, asteroid particles, and meteor ash enter Earth’s atmosphere every year – about 45,000 tons of it.
That’s why scientists believe that planets and moons like Mars and the Moon once had atmospheres, but their gravitational forces weren’t strong enough to hold onto them, so they gradually escaped into space. The Moon is now airless, which is why no sound can be heard there – not even by Neil Armstrong! You might say someone heard something, someone claimed it – but that’s unrealistic, impossible. Neil Armstrong himself said he heard nothing.

Let me tell you about an experiment – you can try it sometime. Take two balloons: one filled with oxygen or pure air, the other with hydrogen or helium. Place both on a truck. If the truck suddenly starts moving from a standstill, you and the oxygen-filled balloon will move backward or lean back. The helium-filled balloon will move forward with the truck. Similarly, if the moving truck suddenly stops, you and the oxygen/air-filled balloon will lurch forward, but the helium/hydrogen-filled balloon will move backward. Strange, isn’t it? Why does this happen? Because oxygen or air is made of relatively heavy molecules. Helium is light. When the truck suddenly stops, the air rushes forward and becomes denser. Light substances always try to escape from dense regions, right? Helium and hydrogen don’t obey Earth’s gravity – so why would they fully obey Earth’s inertia?

The universe is unimaginable without Newton’s three fundamental laws!

[Pic: Wikipedia, CC by 4.0]