EXPLORING SPACE :- GRAVITY

          Raise your arm. Keep it in that position for as long as you can. What happens?

          After some time, your arm begins to hurt. Something seems to be pulling it down. Soon you will have to lower your arm.

          A force called "Gravity" causes you to lower your arm. Gravity acts a bit like magnet, tugging at your arm as if it were a piece of metal.

         We can't see gravity or touch it. we can only feel it. The Earth has gravity that pulls down on everything on or near it. It is this force that keeps us all on the Earth.

        The Moon and the Sun also have gravity. All bodies in the universe have gravity. In fact, gravity helps hold all of them together. Sir Isaac Newton first introduced the idea of gravity, and Albert Einstein added to Newton's ideas.

         Gravity works in a two-way system. This means that all bodies exert a pull on each other. For example, Earth's gravity forces the Moon to circle around it all the time. In return, the Moon's gravity attracts the waters of Earth's oceans to cause tides.

         The force of gravity becomes weaker and weaker as you move away from its source. That is partly why astronauts can float around in outer space. They are too far away for the Earth to have pull on them.

        What do you think would happen if there were no gravity on Earth ?

        DID YOU KNOW ?

        A 1961 Disney film, the Absent-Minded Professor, introduced a particularly far-fetched anti-gravity idea -  "F LUBBER", a super-bouncy "Flying -Rubber".