Magnets have strength. Gravity has strength. You can experiment and see how magnets work. You can not see how gravity works, but gravity is always working.

Magnets work on metals, but only certain metals. Magnets can pull and push only on things made of iron, steel, nickel, or cobalt.

Gravity works on everything in the world. It works on all metals. It works on all things made of wood. It works on water. It works on plants, animals, and people. Lighter things like feathers and balloons stay afloat longer because of the way they ride the air, but they also feel the pull of gravity.

Magnets are made of iron ore. All magnets have an invisible area around them called a "magnetic field". Magnets pull and push on things that enter, the magnetic field. When something is placed outside the invisible magnetic field, it looks like the magnet is not working.

Science and inventors use magnets. Magnets help make many things work. Computers use magnets. Tapes and disc players use magnets. Electric motors use magnets.

Scientists and inventors need to learn and know about gravity. Astronauts can tell us how it feels when gravity is very weak. They know that when they are out in space, that they can not feel the earth's gravity, and that is why everything floats away in space, even water.

Magnets can be so strong that they pass through air, water, and some solid things. Magnets can sometimes push other magnets away. It is easier to see magnets work than to see gravity work. Magnets can be different sizes and shapes. Some are very powerful; some are not.