Have you noticed a significant proportion of my science magic tricks involve fire? I don't actually go around my house lighting things on fire, though I do confess to a certain fondness for those types of projects. I collected my fire magic magic tricks into their very own section, so if you are into fire demonstrations or elemental magic you can find the fire magic tricks in one place. Enjoy!

May 18^th is the birthday of the man who brought us two chemicals that had profound effects on our environment, Thomas Midgley, Jr. He was an American mechanical engineer and chemist who invented tetraethyllead and dichlorodifluoromethane, known by their trademarks Ethyl and Freon. Ethyl was a gasoline additive created to reduce engine knock. It was less expensive than rival additives like ethanol, but contained the toxic element lead. Leaded gasoline was a standard for vehicles from the 1920s to the 1980s dumping lead into the environment the entire time.

The other chemical he discovered was Freon. Freon is actually a collection of chlorofluorocarbon chemicals. They were used in refrigerators, air conditioners, and fire suppression systems. It was a wildly successful replacement for old, less effective refrigerants like methane and ammonia. The problem came when Freon was released into the atmosphere. It would rise into the upper atmosphere and react with the ozone layer where it would break the oxygen bonds and deplete the amount of ozone. The effects were well documented by the 1990s when entire regions of the atmosphere near the poles were missing ozone.

Find out what else occurred on this day in science history.

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If you are in a general science class, you need to know about chemistry, biology, physics, geology, astronomy and any other aspect of basic science. How strong is your command of the science fundamentals? If you are studying one particular science, do you get confused when other areas of science are thrown into the mix? Here's your chance to find out...

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Are you ready to play Crime Scene Investigator? You can test for the presence of blood using the Kastle-Meyer test. This is a simple, sensitive, reliable and inexpensive test that uses materials that are easy to find. Here's what you do.