What is Gravity?
A force that creates attraction between objects is gravity. Almost everyone is accustomed to what gravity is. Ask an individual about gravity and he or she will probably answer you that gravity is something that keeps our feet on the ground. Someone might give an answer of the popular saying ‘what goes up, goes down’. Gravity does not only affect things on Earth, but it also affects the heavenly bodies around it. Everything in the solar system is affected by gravity.
Scientists stressed that gravity is the force responsible for the movement of the Earth. Gravity is the force that makes the Earth revolves around the sun just as the moon revolves around the Earth. Human beings are very well aware of the presence of gravity. However, scientists are still attempting to give a more accurate explanation about its mystery. It was Aristotle who thought of the reason why gravity exists. His theories include the reason why the Earth is at the center of the universe. This theory was known as the ‘geocentric model of the universe.’
On the other hand, an Italian physicist named Galileo supported the ‘heliocentric model of the Solar system’, where the Sun is observed as the center of the system. Galileo was also the first to observe the heavenly bodies. This was made possible due to his invention of the first telescope. The Italian physicist had also theorized that bodies or entities of different weights come down to Earth at the same speed.
It was in the year 1976, when the ‘Law of Universal Gravitation’ was first published. The law was derived from the observations and experiments made by an English scientist named Sir Isaac Newton. Until this present day, his law is still utilized for the description of the gravity forces in relation to day to day contexts. Newton’s first law of gravity states that the gravitational force between objects of two different masses is directly proportional to the square of the gap or distance between the two objects.
Newton also published a second law on gravity. This time he stressed out that the force of gravity is equal to the mass of a body multiplied by its acceleration. This second law explains that two bodies of different masses experience similar force when gravitationally attracted. To better understand this law, imagine an apple falling to the ground. Newton’s second law on gravity describes that the apple and the Earth experiences equal amount of gravitational force.
However, in the 19th century, astronomers started to become aware of the imperfection of Newton’s law. The law was considered as not perfect since it does not accurately gave an explanation on the gravitational occurrences in the solar system. The Mercury’s orbit opened the eyes of astronomers to counter the law on gravity of Newton. Astronomers have also claimed that even the works of Albert Einstein about the gravitational force cannot be considered as perfect. However, even though Newton’s law on gravity was considered imperfect, it is nevertheless being utilized in educating the people due to its straightforwardness and near approximation to realism.