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What is gravity?

Rollercoasters are pulled downwards by gravity.Rollercoasters are pulled downwards by gravity.Gravity is an invisible force that attracts objects to one another. Every object in the Universe, from a pen to a planet, has gravity, but bigger objects have more gravity than smaller ones. Every time you jump up in the air, you fall back down to Earth again. This is because the Earth’s gravity is pulling you towards it.

Newton watches an apple fall from a tree.Newton watches an apple fall from a tree.

Isaac Newton 

The English scientist Sir Isaac Newton was the first person to understand that gravity affects objects in space, like the MoonEarth and Sun, in the same way that it affects things on the Earth—like us. The story goes that he was struck by this idea when he saw an apple fall to the ground. Both the apple and the Earth have gravity, but because the Earth is huge compared to the apple, we see the apple moving towards the Earth and not the other way round. 

Gravity is responsible for the tides. The rise and fall of sea levels are caused by the combined effects of the gravitational forces exerted by the Sun and Moon.

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