May 10, 2012 - Windmill Day

 Windmills seem like an old-fashioned way to harness power—but wind turbines in lines and grids and entire “wind farms” are suddenly modern and popular again.

A wind farm

A modern
wind turbine

The tilted blades or “sails” of a windmill catch the wind and turn, and it is this rotational energy that is captured and transferred to a mechanical device inside. That energy could be used to do many things, from moving huge stones that grind wheat, to pumping groundwater up, to creating electricity.

The first known windmill was built by an ancient Greek engineer in Alexandria, Egypt. Other early windmills were built in China and Persia. These ancient technologies were built in the first to fourth centuries.

People in the Netherlands built many windmills—and, as a matter of fact, the windmills helped to build the Netherlands! Many windmills were used to pump away water and drain land that could then be used for farming. There are more than a thousand working windmills still in the Netherlands—and it is such a common sight in the countryside that the windmill has become a national symbol of sorts.

Another thing people associate with windmills is the fictional character Don Quixote, a Spaniard who wants to restore chivalry and thinks of himself as a brave knight. Don Quixote jousted (fought) with enemies such as hulking giants with huge, flailing arms. Of course these “giants” were really windmills. Because of this character, we might say about somebody, “He's just tilting at windmills,” which means that the person is wasting his time attacking imaginary enemies.

Make a windmill.

Try these instructions, from Zoom.

The Artists Helping Children website gives you printable patterns to use.

Or try DLTK's windmill, an origami creation. 

Also on this date:

Anniversary of Supreme Court ruling: tomatoes are not fruit 

Astronomer Cecilia Payne-Gaposchkin's birthday