Matt Mann!'s photostream

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Presidential Unit Citation

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At one point in time most of use have had a wound up tube of metal called a Slinky and have all pushed it down the stairs in amazement at the movement it makes as if it were alive.

In 1943, Richard James was a naval engineer trying to develop a meter designed to monitor horsepower on naval battleships. Richard was working with tension springs when one of the springs fell to the ground. He saw how the spring kept moving after it hit the ground and an idea for a toy was born.

Another cool fact about Slinky's are that if you drop a Slinky holding 1 end the other end will remain hanging in the air until the part you were holding reaches it. This is due to the fact that gravity is pulling the bottom end down while tension is pulling it up. It will only move when the tension is changed as you let go and the top end reaches the bottom transferring the information that the tension has changed.

Try it out some time its pretty cool

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Have you ever looked at a screw? It is such a simple object, yet something so simple keeps most of the things around us together. Take a look at most of the stuff in your house, or even at your house, and you will see some form of screw.

Around the first century, screw shaped tools became common, however, historians do not know who invented the first. Early screws were made from wood and were used in wine presses, olive oil presses, and for pressing clothes. Metal screws and nuts used to fasten two objects together first appeared in the fifteenth century.