Even since I was a kid, I was fascinated with anything that's 10,000 kilometers above my head - Outer Space that is. I used to go to libraries and check out Astronomy books and see some pictures of stars and planets, and those people who go there and explore! Floating above the earth, doing experiments, those who went to the moon, and now those who plans to go to Mars. Sometimes you can sense this envy, what lucky men or women they must have been.
And fascinates me more is when they are floating in their space stations and rockets, looking like magicians that can float anything they wish to float to, except it is not magic. Weightlessness or Free Fall is the result of having 0 gravity forces acting on your body or an object. You may think of it as there is no gravity around but as Tega Jessa mentioned here: "Gravity actually exists anywhere two quantities of matter exist side by side." Eveything exert a gravitational force on another thing so to speak. But why float if that is the case?
It seems that the reason an astronaut floats because he is actually in a "free-fall" state. Imagine yourself inside a closed box and that box suddenly was released to fall into the earth. Inside the box, you will start to float around, since you cannot feel the pressure exerted outside the box. That is also the same thing astronauts face in space, only difference is they are not falling to earth but rather they are orbiting or circling the earth. It is also said that you also get zero gravity conditions in space flights which are literally explorations to the far corners of our solar system and hopefully beyond.
Enjoy watching some clips by Astronauts and Space Tourists floating around :
A fascinating video of water floating at free fall:
Here is former BBC Science Chief and Popularizer of Science Mr. James Burke explaining Weightlessness training:
You can also do your own research. It's fun!
More information about Weightlessness: