Gravity... A big open question ???

Earth and a satellite

Let's talk about Gravity, What is gravity? Many of you may already be aware of what it means. So, let me share my thoughts on this topic. We shall start with a quick definition. According to wikipedia,

"Gravity or gravitation is a natural phenomenon by which all things with mass and energy including planets, stars, galaxies and even light are brought toward(or gravitate toward) one another by a force that is proportional to the masses of the two bodies and distance between them."

Any two bodies in the world that have a mass will be attracted towards each other by a force that is proportional to their masses and the distance between them.

Universal law of gravitation

Albert Einstein's general theory of relativity is considered to be most accurate in measuring the gravitational force between two objects.

'Einstein, In his general theory of relativity, describes gravity not as a force, but as a consequence of curvature of space time caused by uneven distribution of mass' 

But, even Einstein's theory has not been reconciled(to exist together) with the quantum mechanics, which is a study of matter at the smallest scale of atoms and molecules. But, where exactly does the force come from ? what is the reason of gravitational pull ? 

Origin of gravitational force ?

Consider earth, the closer we stand towards the earth, the harder we are pulled towards it right ? or not ? Scientist said that everything on earth experiences a force that pulls the object towards it with an acceleration of 9.8 m/s. Okay, but what if the object is 10,000 m above the ground, would it still experience the same amount of acceleration ? and what if the object is a million kilometers away, would it still experience an acceleration of 9.8 m/s towards earth. As Newton described the force to be inversely proportional to the distance between two objects, that is not the case. The farther we move from the earth, less force we experience. Well, that makes sense. 

When we talk about origin, the one thing that comes to mind is the 'center of mass of the body'. It is a hypothetical point where entire mass of an object is assumed to be concentrated to visualize it's motion. Now, visualize a ball, a hollow ball. Center of mass of a hollow ball is also situated at the center of a ball where the ball is hollow i.e. no mass. As we know the gravitational pull is generated from mass, center of mass should not be the reason for the origin of the force. 

"A big open question"

Gravitational force in itself is a big open question to the world of physics. We don't know where it comes from, it's origin and the single most important aspect of science, reason. Is the overall mass of an object responsible for it ? But, how can a static mass produce anything in the first place that too a force that can bind planets to each other... No one knows the reason and that's why the 'Science' is fascinating. It keeps us curious.

Thanks for reading, Happy life and stay tuned.