
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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