Newton's Law of Universal Gravitation: What It Is and How It Works

 Sir Isaac Newton's law of universal gravitation states that any two bodies in the universe attract each other with a force that depends on their masses and the distance between them. The law was first proposed in 1686, but it took some time before the concept of universal gravitation was accepted by other scientists and mathematicians. This article explores what this law is and how it works, plus its applications in the real world and its limitations.

Gravity

Gravity is a fundamental force in nature. In fact, it can be regarded as one of the four fundamental forces along with electromagnetic, strong nuclear and weak nuclear forces. When an object is dropped on Earth, what we actually observe is not just falling but accelerating motion due to gravity pulling objects down at 9.8 m/s2 downward towards its center mass. A perfect sphere has equal attractive force in all directions because there are equal numbers of positive charges (protons) and negative charges (electrons) distributed evenly throughout. In fact, Newton’s universal law states that any two bodies attract each other with a force that is directly proportional to their masses and inversely proportional to square distance between them.

What is gravity?

When we think about gravity, our minds often wander to objects with huge mass like stars or planets. But gravity is also present in tiny particles. Newton’s law of universal gravitation holds that every object in space exerts a gravitational force on every other object in space. So, if you picture a particle being pulled down by Earth’s gravity, it will experience a gravitational pull from Earth but also from everything else that is around it. As long as there are two objects in space and one has mass, then they are affected by each other’s gravitational pull.

The gravitational force between two objects

gravitational force

This force is described by Newton’s law of universal gravitation. Let us examine how it works. Sir Isaac Newton proposed his law on July 5, 1687, nearly nine years after he had published a more famous law (the law of inertia) that we still use in physics today. His own discovery occurred while he was trying to figure out why objects fall to Earth instead of following a curved path like planets do around their suns. He did not notice any curvature in falling objects; they simply dropped straight down, or toward whichever part of Earth happened to be beneath them at any given moment.

Applying Newton’s law of universal gravitation in daily life

We can use Newton’s law to calculate how an object will move through space in response to gravitational forces, if we know its initial velocity, final velocity, mass and one other important variable: time. Applying Newton’s universal law in real life example would be when we launch a satellite into space; it will keep orbiting around Earth until some external force causes it to crash or change direction. An example is with astrology; where our orbit around the sun causes each sign (Aries, Gemini, Cancer, Leo, Virgo etc.) to have different characteristics based on what season we were born in.

Additional resources

Newton’s law of universal gravitation states that every point mass attracts every other point mass by a force pointing along the line intersecting both points. These forces are directly proportional to the product of their masses and inversely proportional to the square of their distance apart. This is an example of an inverse-square law. Newton’s law was one explanation for Kepler’s laws. If a planet orbited around a star, then it would orbit in a certain way. And so, we can use Newton’s law to explain why planets orbit how they do based on where they are orbiting from compared to each other as well as what objects surround them.