What’s the Weather? Check Your Weatherglass Barometer

Ted Beyer

by:   Ted Beyer

Predicting the weather is an age-old guessing game.

Over time, more and more sophisticated devices have been developed to aid in the guessing game.  Indeed, some of the largest computers in the world today are dedicated to modeling the weather using millions of data points collected all over the world—all in an effort to determine if going to the beach this weekend is a good idea, or if you should just stay home and binge watch Game of Thrones (again).

torricelli engraving from The Granger CollectionAfter temperature, one of the earliest scientific observations about the weather is the variation in barometric pressure.  Local changes in air pressure usually signal changes in the weather.  Falling pressure generally indicates rain, snow or wind storms, and increasing pressure most often indicates nicer weather.

One of the earliest gadgets used to try and track barometric pressure was the Weather Glass, also known as the Goethe Barometer [1].   Evangelista Toricelli [2] came up with the first truly accurate barometer—the classic, mercury-filled device—sometime around 1643-44.  [Note: Educational Innovations has a mercury-free version of this Science classroom “must-have.”] Read the rest of this entry »

The Chemical Spill and the River

Brian Herrinby: Brian Herrin

One of the difficulties of modeling a flowing water system is the size of the system and the quickness of the flow.  This often makes demonstrations hard to visualize as things happen so quickly.  The model I designed uses large transparent plastic cups and clear tubing that connects them to easily demonstrate how a river can become contaminated by a toxic spill or dump and how the toxic material slowly works its way downstream creating devastation along the way.  In time, the river will eventually run clean, but the damage takes much longer to disappear, and some damage may be permanent.

Begin by setting up a mock river system using six to ten separate cups.  There is no limit to the number of cups you can use.  The siphon tubes used to connect the cups are made of 6.4mm (inside diameter) clear tubing cut into 40cm lengths.  You can use aquarium tubing and smaller plastic cups but a slower system will result.  You will need one less tube than the number of cups you use.  For a self emptying system, you can insert a smaller tube into the last cup that empties into a larger container.

Chemical spill set up Read the rest of this entry »