The universal gravitation is universal in its nature. Newton is not known only for discovering gravity, but he is famous for finding out that gravitation is universal. Each object is attracted to the other through gravitational pull. The gravitational force is related to the square of the distance between their centres and is directly proportional to the masses of both objects. The force that caused the apple to accelerate must be proportionate to its mass. The same force that caused the apple to fall causes the earth to accelerate upward.

Newton’s Law of Universal Gravitation 

Because the gravitational force is proportional to the mass of both interacting objects, more massive objects will attract each other with a stronger gravitational attraction. As a result, as the mass of each object increases, so does the gravitational attraction between them. 

When one object’s mass is twice, the gravitational force between them is likewise doubled. When one object’s mass is tripled, the gravitational force between them is also tripled. The force is quadrupled when the masses are doubled, and so on. There are gravitational interactions between the earth and other objects, as well as between the sun and other planets.

There are gravitational interactions between the earth and other objects, as well as between the sun and other planets. All objects have gravitational interactions, and the intensity of these interactions is proportional to the product of their masses.

Newton’s groundbreaking concept was that gravity is universal and that all objects attract in proportion to their mass product. The majority of gravitational forces are too small to be noticed. Only when an object’s mass reaches a certain size can gravitational forces be detected.

Limitation of Gravitational Force

• Newton’s rules are only applicable in inertial frames of reference, which is the major constraint of gravitational force. When constructing force equations, we must include pseudo force (-ma) in addition to all other forces if the body is in an acceleration frame of reference. 
• The laws of Newton apply to point objects.
• The laws of Newton apply to stiff bodies. A body is said to be rigid if the relative distance between its particles does not change for any deforming force. 
• For objects travelling at a comparable speed to light. The results of Newton’s law of motion do not match the experimental results. Hence Einstein’s special theory of relativity must be applied.
• This law is only valid for point masses on extended bodies. It cannot be directly applied because, as per Newton’s law of gravitation, if there are two point masses m1 and m2, these will attract each other with a force F. 
• When astronauts made careful observations of the orbit of Mercury, they noticed that its orbit exhibited some patterns that the law of universal gravitation was not able to explain. 
• It was not until the early 20th century that Einstein constructed a more advanced theory of gravity so that scientists could predict all the details of the motion of Mercury. 
• Even with the calculus, the universal law of gravitation cannot account for the details of some of the motions. 
• As per general relativity, we cannot use Newton’s law in the presence of extremely massive objects. 

Applications of Universal Law of Gravitation 

For objects that are lying at very vast and small distances, Newton’s law of universal gravitation applies. But, it fails when the distance between two bodies is less than 10-9m. 

• The assumption about the orbit and time period of modern artificial satellites made on the basis of this law proved to be true 
• The assumption about solar and lunar eclipses made based on this law is accurate. 

Conclusion

Newton’s law of universal gravitation states that two bodies in space pull on each other with force proportional to their masses and the distances between them. Large objects which are orbiting one another, the moon, the earth, this means that they actually exert a noticeable force on one another. 

Sir Isaac Newton discovered and articulated the concept of gravitation force, and his concept suggested how gravitational attraction affects both falling objects and the motion of celestial bodies. However, there were certain limitations to his universal law of gravitational theory. The laws were not applicable under various circumstances. Scientists like Max Kepler and Robert Hook made further observations and gave new theories that could fit scientifically.