Gravity and Orbital Motion

Explore the force that keeps our feet on the ground and planets in orbit

Key Knowledge

  • 1Gravity is a force of attraction between objects with mass. The more massive an object is, the stronger its gravitational pull.
  • 2Earth's gravity pulls objects toward its center at approximately 9.8 meters per second squared (9.8 m/s²).
  • 3Orbital motion occurs when an object's forward motion balances with gravity, causing it to fall around rather than into the object it's orbiting.
  • 4Planets orbit the Sun in elliptical paths due to the Sun's gravitational pull.

Interactive Illustration

Explore this interactive 3D model to better understand gravity and orbital motion. You can rotate, zoom, and interact with the model to see the physics in action!

Historical Context

From Falling Apples to Curved Spacetime

Our understanding of gravity has evolved dramatically over centuries. From Newton's realization that the same force that makes apples fall also keeps the Moon in orbit, to Einstein's revolutionary concept that gravity is actually the curvature of spacetime caused by mass.

Key Figures

Sir Isaac Newton

Developed the law of universal gravitation in the 17th century, describing how all objects with mass attract each other.

Albert Einstein

Proposed the theory of general relativity in 1915, explaining gravity as the curvature of spacetime caused by mass and energy.

Johannes Kepler

Formulated the laws of planetary motion in the early 17th century, describing how planets move in elliptical orbits.