Main idea

Hello. You can't see me, but I am everywhere. I am the reason your ball comes back down when you throw it up. I am the one who pulls you gently back to the ground when you jump. I hold all the water in the big oceans and keep your feet on the soft grass when you run. I am like a big, invisible hug for the whole world. Do you know my name? I am Gravity.

For a long, long time, people felt me but they did not know my name. One day, a man who loved to think sat under a big, shady tree. His name was Sir Isaac Newton. He was very curious. Plop. An apple fell from a branch and landed on the ground. He looked at the apple and started to wonder. Why did the apple fall down and not up? He thought and thought. He realized my invisible pull works on everything. I keep the big, bright Moon near the Earth. I keep our Earth near the warm Sun. He gave me my name, Gravity, and told everyone about my special job.

Now that you know about me, you can see me working everywhere. I help builders make tall, strong houses that stay put. I help astronauts fly their spaceships and come safely home. I even help you have fun. When you slide down a slide, whee, that's me pulling you down. I am always here, keeping our world safe and sound. I am your super strong, invisible friend, Gravity, and I'm always here to hold you close to home.