A Science Odyssey Guest 2 wearing an Albert Einstein mask

How do you define gravity?

Gravity is a force. It's the force that pulls me and you into our seats and tugs on an apple in a tree. It's the force that keeps the Moon in orbit around the Earth and the Earth in orbit around the Sun.

The force of gravity is described by the law of universal gravitation. The law states that gravity is universal because it applies to all bodies throughout the entire known universe. It also states that gravity is mutual. This means, for example, that not only is the Moon attracted to the Earth, the Earth is also attracted to the Moon.

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