Newton’s Universal Laws: The Gravity Behind Every Apple and Planet

Isaac Newton’s insights into motion and gravity transformed our understanding of the universe. His three laws of motion describe how objects behave, whether it’s an apple falling from a tree or a planet orbiting the Sun.

The first law, the law of inertia, states that objects remain at rest or move uniformly unless acted upon by an external force. This explains why a rolling ball eventually stops due to friction, and why planets continue their orbits without constant propulsion.

Newton’s second law, expressed as F=ma, links force, mass, and acceleration. It tells us that the same force will accelerate a lighter object more than a heavier one. However, gravity is unique in that it accelerates all objects equally regardless of their mass, a fact famously demonstrated when an astronaut dropped a hammer and feather simultaneously on the Moon.

The third law emphasizes that forces come in pairs: for every action, there is an equal and opposite reaction. This principle explains why pushing against a surface results in an opposing force that supports us.

Extending these principles, Newton formulated the universal law of gravitation, revealing that every mass attracts every other mass with a force proportional to their masses and inversely proportional to the square of the distance between them. Remarkably, he showed that the gravitational pull of a spherical body acts as if all its mass were concentrated at its center, simplifying calculations for planets and apples alike.

These laws laid the foundation for classical mechanics and remain essential to physics and astronomy today, helping us understand everything from everyday motion to the grand dance of celestial bodies.

Newton’s legacy continues to inspire curiosity and scientific discovery, reminding us of the unity underlying the cosmos.

References:
Starts With A Bang,