Sir Isaac Newton is famous for discovering gravity!
Here's a simple explanation for kids:
Newton was a scientist who lived a long, long time ago. He was sitting under an apple tree when – plop! – an apple fell right near him. That got him thinking: Why do things always fall down to the ground? Why doesn't the apple float up into the sky?
He realized there must be a force pulling everything towards the Earth. He called this force gravity. Gravity is what keeps us on the ground, makes balls fall when we drop them, and keeps the moon orbiting the Earth! So, next time something falls, remember Isaac Newton and his apple, and you'll know it's all thanks to gravity.