Law of Gravitation
From the apple that famously fell on Newton's head—inspiring his laws of motion and universal gravitation—to Einstein's revelation of gravity as the warping of spacetime by mass and energy, our understanding of gravity has evolved dramatically.
Although modern physics views gravity as a geometric curvature of spacetime rather than a conventional force, Newton's model of gravitation remains remarkably accurate and practical for most situations:
It is still more than good enough to
get us to the Moon and back.
This series of lessons explores the classical principles of gravitation and its consequences as formulated by Sir Isaac Newton.
Law of Gravitation
his video introduces Newton's Law of Gravitation and highlights a major milestone in physics: scientific unification.
Unification occurs when an overarching model connects two seemingly separate phenomena. Newton realized that the force causing an apple to fall to Earth is the exact same force holding planets in their orbits.
As you watch, notice that the Law of Gravitation is another key example of an inverse square law.
It is important to note that Newton's work provided a mathematical description of how gravity behaves, rather than an explanation of what causes it—a deeper mechanistic explanation did not arrive until Einstein published his General Theory of Relativity in the early 20th century.
We are now ready to try a sample problem
Below is a sample problem with a video that explain how to solve it. It is suggested you try the problem beforehand, as this actually aids understanding, even if you are unsure if you are correct.
