All About Gravity

Gravity is one of the fundamental forces in the universe, alongside electromagnetism and the strong and weak nuclear forces. But over time, gravity has been a sort of puzzle for scientists. Ancient scholars and physicists who tried describing the world came up with their explanations as to why things towards the ground. Sir Isaac Newton described gravity as a force between all objects with mass; he described gravity as mysterious at a distance; on the contrary, Einstein described gravity as the bending of space and time, but the reality is that gravity keeps us from falling off the earth surface. 

History of Gravity 

Gravity is not all about things falling; because of gravity, clocks in Jupiter tick slower than clocks on Earth, and there are regions in space where nothing, not even light, can escape. A student of Plato, Aristotle gave the earliest definition of gravity; Aristotle divided matter into Earth, water, air, and fire and stated that things moved because they wanted to go back to their proper space. Earth belonged to the very centre; water would wrap around Earth and fire on top of water and air on top of a fire.    

Two thousand years down the line, Galileo gave a different theory on gravity. He states that less dense objects have a harder time going to the bottom of a container, so if we replace them with the air, we will observe the same behaviour, and less dense objects take longer to reach the ground because of air resistance. If you remove that air, anything should go down at the same rate, explaining the behaviour of objects that we can easily observe. 

Gravity is something that makes the planet move; Sir Isaac Newton came up with the theory of gravitational force. Law number one states that planets move in an ellipse around the sun, meaning there must be something pulling Earth towards the sun, making earth change direction every time. Law number two states that planets will sweep out equal areas at equal intervals because the nearest planet is to the sun and has a stronger pull. This stronger pull creates large acceleration experienced by the Earth the faster it moves. ; a number three, the ratio of the square of the planet’s period and the cube of its semi-major axis is the same for all planets meaning that whatever is holding one planet in its orbit must be the same thing holding other planets. 

Gravitational Force

The universe has a lot of forces, pushes and pulls. We are constantly pushing or pulling something, even if on the ground, but in the universe, there are four fundamental forces from which everything is derived, the strong force, the weak force, the gravitational force, and the electromagnetic force. Here, gravitational force can be defined as something which attracts any two objects with mass. The gravitational force always pulls the masses together but never pushes them back. Every object, including human beings, pulls on every other object in this universe. This is defined as Newton’s Law of Gravitation. Objects that far do not pull on each other; we don’t have huge mass, so we are not pulling much on those objects. 

The equation for Newton’s gravity force is: 

Fg = Gm1m2/r2 

Here G refers to the gravitational constant, equal to 6.67 x 10-11N m2/kg2

Fg is the gravitational force between masses m1 and m2 

The equation given above is also referred to as the gravitational force between two objects. 

The gravitational force is the central force that works across the line joining the centres of two bodies, and this force is always a long-range force. 

Conclusion

Without gravity, we wouldn’t exist; it provides the force which keeps us on the surface of the Earth and the Earth orbits around the sun. It led to the formation of the solar system. It is the gravitational attraction of all the material in the sun, pulling it tightly together, making it possible for nuclear fusion to take place, giving us heat and light. Gravity, in a nutshell, can be defined as matter that is attracted to all other matter; the more the matter, the closer objects are to each other, and the bigger the mass, the more attractive will be the force, unlike electromagnetism which repels and attract, gravity always pulls things together.