The gravity is a natural phenomenon. The scientific term for gravity is the force that is required to change the speed or direction of a moving object.
There is a gravity between any two bodies with a force proportional to their mass.
The factors that affect gravity are mass, distance and placement.
The gravity vary as those factors vary. Gravity is the force that keep the planets revolving in their orbits around the sun and keeps the moons revolving around their planets.
The earth gravity is what keeps us from flying into space. Also the gravity is responsible for the formation of tides, the fluid convection and some other natural phenomenons that we can see.
Gravity was first noticed first by Brahmagupta (598, 668) the Indian mathematician and astronomer.
Tycho Brahe (1546, 1601), a Danish astronomer and alchemist, had the most accurate astronomical observations and his data was used by his student Johannes Kepler.
Galileo Galileo (1564, 1642), the famous Italian physicist, mathematician, astronomer and philosopher is the scientist who realized that there is a force that makes the heavy objects fall faster than the light objects.
Johannes Kepler (1571, 1630), was a German mathematician, astronomer and astrologer. He noticed that the force that produce the tides are caused by the moon and the laws of planetary motion.
But of course when mentioning the gravity, the most famous name that comes to our mind is
Sir Isaac Newton (1642, 1727).
Newton was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian.
He read the work of Galileo Galileo and Johannes Kepler and put together their work and in the year 1687 when he was sitting under the tree and an apple fell, he put that all together to discover the gravity and put the three laws of motion.
Newton was the first to call that force Gravity.
Newton also used the information from the previous scientists to prove that the sun is the center of the solar system and not the earth as people used to believe.
Then came Albert Einstein (1879,1955) as a German-born theoretical physicist who lived in USA since 1933.
Einstein came up with different idea about gravity. Gravity is produced from the warping or the dent of space and time.