Gravity is a fundamental force of nature that causes all matter to attract all other matter in the universe. On Earth, gravity pulls objects downward toward the planet's center, which is why things fall when dropped and why we stay grounded
. How gravity works:
- Every object with mass exerts a gravitational pull on every other object with mass. The strength of this force depends on the masses involved and the distance between them. More massive objects exert stronger gravitational forces, and the force decreases with the square of the distance between objects
- For example, Earth’s large mass produces a strong gravitational pull that keeps us and everything else on its surface. Smaller objects, like a TV, also exert gravity, but their pull is negligible compared to Earth’s
- Gravity is what keeps the Moon orbiting Earth, Earth orbiting the Sun, and planets held in their orbits around stars. Without gravity, objects would move in straight lines and not form stable orbits
- Weight is the force of gravity acting on an object’s mass. This means your weight changes slightly depending on your distance from Earth’s center (like being on a mountain vs. sea level)
- In space, astronauts experience weightlessness not because gravity is absent, but because they are in continuous free fall around Earth, creating a sensation of weightlessness
Historical context:
- Isaac Newton was the first to formulate a quantitative theory of gravity in 1687, realizing that the force pulling apples to the ground is the same force governing planetary motion
In summary, gravity is the invisible force that attracts all matter to each other, with Earth’s gravity pulling objects toward its center, giving us the experience that "what goes up must come down"
