A Brief Explanation Of Gravity And The Possibility Of Creating Artificial Gravity

Gravity is part of our daily life, but not many of us truly understand it. So here is a brief explanation of this natural force and a look into the possibility of creating artificial gravity in space.

How Does Gravity Work?

It was not until recently that we have a clear idea of what gravity is, but before it, human had been thinking hard to understand what it was.

In the time of Greek philosophers, they thought that our planet and the stars they saw belong to the gods’ realm, so they came up with a concept called natural motion. The idea was not developed further than that for centuries until Galileo and Brahe came up with their theories, which paves the way for the revolutionary findings of Isaac Newton.

As Newton defined it, gravity is the force that keeps the Earth orbiting around the Sun. So whenever you throw something away or jump into the air, the consequence is, without doubt, you and the object will eventually drop back to the ground.

Einstein has a different idea to Newton of what gravity is. According to him, it is a curvature in the continuum of time and space. An object’s mass will cause the space surrounding it to curve and bend, thus distorting the path light and the object traverse. This, in turn, cause what we feel as gravity.

So any object inside the field affected by the gravity of another celestial body will be impacted as the space it moves through is distorted toward the latter object.

He also came up with the concept of the equivalence principle, which said that inertial and gravitational forces have the same nature and most of the time, we cannot tell them apart.

For example, if you are in a rocket leaving the Earth without any window to see where you are going, you will have difficulty distinguishing if what you feel is our planet’s gravity or just the result of the rocket accelerating in a particular direction.

Do We Understand Gravity?

When it comes to how deep we know gravity, the answer is yes, and no. While it is one of the most studied phenomena on Earth, what we know about it is still limited.

Newton and Einstein have made significant progress in defining the force, but so far, we are not entirely sure if gravity is real.

Einstein thought that it was not a real force but rather a result of space-time’s bending. What we can be sure of is that objects with mass attracted each other, and the further they are, the weaker the force.

Another thing we know of it is that it is the weakest force in nature. With an object as massive as the Earth, we can escape its gravity temporarily by jumping off the ground.

However, everything seems to change at the quantum level, and we do not know why this happens. Our theories are right on a grand scale. It helps us predict the movements of big objects, but when it comes to the quantum scale, they are not applicable.

This is by far on of the greatest issue in physics and many experts hope that one day we will have a universal theory for both quantum and macro physics.

How Does Gravity Help Us?

Gravity explains why objects with a mass on Earth do not float all the way to space. It also makes sure that our planet traverse within the “Goldilocks Zone,” a safe distance from the Sun so that water can be at the liquid form, which can ensure the existence of life.

We have air to breath is also thanks to gravity, as it keeps the atmosphere in place. Mars’s mass is about one-tenth that of the Erath, so its gravitational pull is weaker than Earth’s. As a result, our atmosphere is 100 times denser than Mars’.

However, the gravity pulls are not equal at different parts on Earth. The force is stronger in places with the more mass underground.

Can Gravity Be Created?

As Einstein proposed, gravity is created as space-time’s distortion caused by bodies. So theatrically, artificial gravity is possible. What we need is linear acceleration, such as a rocket, according to Einstein.

So with a ship large enough, it can produce a force indistinguishable from that of the Earth on its passengers. However, there is a difference though. Since Coriolis forces will appear, things will traverse in a curved instead of a straight path.

There is an issue. The faster the ship accelerates, the stronger the gravitational pull on the passengers. This is not a problem for a space station and other stationary craft, but it will be catastrophic for the passengers of an aircraft that have to travel at high speed.

If the aircraft flies at a small fraction of the speed of light, the crew will experience over 4,000 gs, 100 times higher the acceleration that can prevent blood from running in human’s veins.

A solution to this problem is to use conductive floors and electromagnets in aircraft. However, another problem is the downward force. For now, the only effective workaround we have is to create an anti-gravitational field.

This possibility is being tested at ALPHA Experiment at CERN where experts are experimenting with trapped antihydrogen atoms, the antimatter counterpart of hydrogen.

The experts hope that by comparing antihydrogen and hydrogen, we can understand the symmetries of antimatter and matter, thus coming up with a way to measure the antimatter’s gravitational acceleration.

If the results prove that antimatter accelerates at a negative value with effect from the Earth surface’s gravitational field, we can construct a gravitational conductor to prevent the gravitational force from taking an impact on us.

So the possibility of artificial gravity will depend on the results of these experiments. If it falls down, the idea of a gravitational conductor will be ruled out. However, if it falls up, the idea is viable. The best result we can hope for is to build a warp drive, which ca deform time and space.

So until we find particles that possess negative gravitational mass, the only way to create artificial gravity is by acceleration.