Defining Gravity

The video explains the concept of gravity, its significance in keeping everything grounded on Earth, and how it was first studied by Isaac Newton. It recounts the famous story of Newton and the apple, illustrating how gravity acts on all objects regardless of their weight. The video also includes a simple demonstration using a tennis ball to show how gravity pulls objects down, regardless of the direction they are thrown.

Explain the concept of gravity as described in the text. How does it relate to life on Earth?

What is the significance of the phrase 'what goes up must come down' in relation to gravity?