Gravity was discovered 3 centuries ago by a mathematician and physicist named Sir Isaac Newton. He discovered that there is a specific force,which we call gravity, that is required to change the speed or direction of something that is moving. This same force he figured must cause apples to fall from trees! After researching this hypothesis he wrote the law of gravity. This law is a mathematical explanation for the way that things attract based on experiments and observations.

Gravity is an invisible pulling force between two objects. These two objects can be anything from a grain of rice to a planet in the solar system. Nothing can escape it.

What is Gravity?
The amount of gravity that an object has depends on a few things. One of these things is where on the planet you are. Believe it or not the amount of gravity varies from place to place on earth (Click here to see a Map). Another thing that affects the amount of gravity an object has is how big the object is. The bigger the objects mass the more gravity it will have and the smaller the mass of the object the less gravity. The final thing that affects gravity is the distance between the two objects. The closer they are the stronger the gravity will be.

Where is Gravity?
Gravity is everywhere. It is between everything and it is everywhere. It is on Earth, moons, stars, and even in space. Although gravity is in space and keeps our planet and all others in orbit, people in space do not always feel the effects of gravity and can float around.

Why do we need gravity and why is it so important?

Gravity is a very important and critical part of our everyday lives and you probably don’t even notice. Here are some things that gravity does for us everyday:
Gravity brings us back down to the ground when we jump up. It stops us from floating into space.

Gravity keeps our food on our plates and our drinks in our glasses.

Gravity keeps the Earth in orbit around the sun and keeps us warm.

Gravity also keeps the water on the Earth, the inhabitants on Earth, and the Earth’s atmosphere in its place.

Gravity pulls rain and snow down to our rivers.

Other Gravity Facts:

Gravity can cause health problems such as bone loss, muscle atrophy, and fluid shifts.

If you were to go to another planet you wouldn’t weight the same as you do on Earth due to the change in gravity. This web site can will show you what you would weight else where in the universe. http://www.exploratorium.edu/ronh/weight/

The equation for calculating the force of gravity between two objects is F12=F21=Gm1m2/R2

Gravity also guides the growth of plants and other vegetation.

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