Weightless Rat

How do you weigh a weightless rat to see how it's grown? Imagine you are a researcher on board of the Space Station and you are studying the growth of rats in zero gravity conditions. How are you going to determine their weight? Before reading the answer try to figure out a method of your own.


You can't use a scale in space because a scale depends on gravity, but you can measure mass another way. Hold the thin plastic ruler against the edge of a table, put one end to the side, and let go. See how fast it whips back and forth. Now use a rubber band to attach a coin to the end of the ruler and repeat step 1. Has the ruler slowed down? Try the same experiment with another object. It works this way in space, too. The rat is put in a pouch with its head sticking out and "bounced" back and forth. The slower the movement, the more it's grown. Do you think the rat will get dizzy after this experiment? What do you think he will feel? You are right! The rat will feel the effects of acceleration and this will have some “side effects” on him.

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