16 September Science Special Events

16 September Science Special Events

Ozone layer

16 September 1987, the "Montreal Protocol on Substances that Deplete the Ozone Layer" was signed, agreeing that the production and consumption of most compounds that deplete ozone in the stratosphere, such as chlorofluorocarbons (CFCs), were to be phased out by 2000. It was further adjusted and amended at subsequent Meeting of the Parties between 1990 and 1997. Because of their relatively high ozone depletion potential, several man-made compounds in addition to (CFCs), carbon tetrachloride, methyl chloroform, and halons were targeted first for phaseout. Now, the U.S. Clean Air Act, for example, bans the release of ozone-depleting refrigerants the during maintenance or disposal of air conditioners and other refrigeration equipment.

Darwin reaches Galapagos

16 September 1835, British naturalist Charles Darwin aboard the ship HMS Beagle,arrived at the Galapagos archipelago, a cluster of islands on the equator 600 miles west of South America. During his five weeks studying the fauna in the Galapagos, Darwin found the giant tortoises there greatly differed from one another according to which island they came from. Moreover, many islands developed their own races of iguanas. These observations contributed to his theory of "natural selection," that species evolved over thousands of millions of years. 

Solar eclipse

16 September 1662, the first recorded astronomical observation of the first Astronomer Royal was John Flamsteed's observation of a solar eclipse from his home in Derby at the age of sixteen, about which he corresponded with other astronomers. Flamsteed's interest in astronomy was stirred by the solar eclipse, and besides reading all he could find on the subject he attempted to make his own measuring instruments.

Oxygen

16 September 1774, Lavoisier observed that heating mercuric oxide produces metallic mercury. He thought the reaction might have been caused by contact with iron; he made no note of gas evolution in his notebook.