What would happen if gravity disappeared on Earth?

Gravity is something we never really think about, but we assume two things: it's always present, and it never changes. If the Earth's gravity were to dramatically alter, it would drastically affect nearly everything, as so many things are designed with our current gravitational conditions in mind.

Before diving into gravity changes, it's important to first grasp what gravity actually is. Gravity is a force of attraction between any two atoms. For example, when you place two golf balls on a table, their atoms will exert an almost imperceptible gravitational pull on each other. If you used two enormous pieces of lead and the most accurate tools, you could measure this tiny attraction. It's only when large numbers of atoms are involved, like in the case of Earth, that gravitational force becomes noticeable.

The reason gravity on Earth stays constant is that the Earth's mass remains unchanged. To alter gravity, we would need to drastically alter the planet's mass. Such a massive change in mass is not something that will occur anytime soon.

Could we exist without gravity?

Now, let's push the limits of imagination and consider a scenario where, one day, the planet's gravity just switches off, and suddenly there's no gravitational pull on Earth. That would spell disaster. We rely on gravity to keep everything grounded — cars, people, furniture, even the papers on your desk. Anything not fixed in place would have no reason to stay put and would start floating. But it's not just everyday objects that would be floating away. Gravity also keeps the atmosphere and the water in our oceans, rivers, and lakes in check. Without gravity, the air would have no reason to stay and would shoot off into space. This is similar to what the moon experiences — it lacks sufficient gravity to hold onto an atmosphere, leaving it with a near vacuum. In the absence of an atmosphere, life would cease instantly, and any liquid would evaporate into space.

In simpler terms, life wouldn't last long without gravity on Earth.

If gravity were to suddenly double, the consequences would be just as severe, as everything would become twice as heavy. This would lead to major problems with any structural elements. Buildings, bridges, skyscrapers, table legs, and support columns are all designed with normal gravity in mind. Most structures would collapse quickly if they had to bear double the usual weight. Trees and plants would struggle, and power lines would face significant challenges. The atmospheric pressure would double, which would drastically alter the weather.

This answer highlights just how essential gravity is to our existence. We cannot survive without it, and any alteration to it would be disastrous. Gravity is truly one of the few unchanging forces in our world!