* Mass: Everything in the universe has mass, which is a measure of how much matter it contains.
* Gravity: Gravity is a fundamental force of nature that attracts objects with mass towards each other. The more mass an object has, the stronger its gravitational pull.
How it Works:
1. Distortion of Spacetime: According to Einstein's theory of general relativity, mass warps the fabric of spacetime. Imagine a heavy ball placed on a stretched sheet – it creates a dip. This dip is analogous to the warping of spacetime caused by mass.
2. Following the Curve: Objects with mass follow the curvature of spacetime created by other objects. This is why planets orbit stars and why apples fall to the ground.
3. Gravitational Attraction: The greater the mass of an object, the greater the curvature it creates in spacetime, and the stronger its gravitational pull.
Examples:
* Apple falling from a tree: The Earth's large mass creates a strong gravitational pull that attracts the apple downwards.
* Planets orbiting the Sun: The Sun's massive gravitational pull keeps the planets in their orbits.
* Tides on Earth: The Moon's gravity pulls on the Earth's oceans, creating tides.
In summary: Everything experiences gravity because it has mass, and mass creates a curvature in spacetime that causes other objects with mass to be attracted to it.
