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General
In 1973, four metric distance road signs, the first in the U.S., were erected along Interstate 71 in Ohio. They showed the distance in both miles and kilometers between Columbus and Cincinnati, and Columbus and Cleveland. As early as 1790, Thomas Jefferson proposed a decimal measurement system, similar to the metric system. In 1968 a study was ordered by Congress. By 1971, a report recommended a switch to the metric system and established a 10-year target time to accomplish it. This led to a National Metric Conference in 1973, which prompted Ohio to display metric highway signs. The Metric Conversion Act (1975) planned a voluntary conversion to the metric system, which produced little voluntary action.
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Earth Science
In 1966, the U.S. launched its first operational weather satellite, ESSA-1 to provide cloud-cover photography to the U.S. National Meteorological Center for preparation of operational weather analyses and forecasts. The spacecraft was an 18-sided polygon, 42-in. diameter, 22-in. high and weight 305-lb. It was made of aluminum alloy and stainless steel, then covered with 9100 solar cells. The solar cells served to charge the 63 batteries. Its two cameras were mounted 180 degrees opposite each other along the cylindrical side of the craft. A camera could be pointed at some point on Earth every time the satellite rotated along its axis. ESSA-1 was able to view the weather of each area of the globe, photographing a given area at the exact same local time each day.
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Biology
In 1944, DNA was identified as the hereditary agent in a virus, published in a report by O.T. Avery, Colin MacLeod, and Maclyn McCarty. This crucial discovery in molecular genetics - that genetic information is carried in the nucleotide sequence of DNA - arose incidentally while studying pneumococcus to monitor the epidemic spread of pneumonia. Since 1928, when British physician Frederick Griffith had found that extracts of a pathogenic strain of that virus could transform a harmless strain into a pathogenic one, scientists had searched for the "transforming factor." The work by Avery, et al., now identified the transforming molecule as DNA, having ruled out, through extract digestions, RNA, protein, and polysaccharide capsular material.
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Chemistry
In 1863, John Newlands, an English chemist (1837-1898), organized the known elements by listing them in order by atomic weight, according to his "Law of Octaves." This was based on noticing that after each interval of eight elements, similar physical and chemical properties reappeared. He thus created natural families and periods. The article "On relations among the Equivalents," appeared in Chem News, vol. 7, pp. 70-2. The English Chemical Society ridiculed the idea. So little significance was then attached to atomic weights, he was once asked why not just order elements by their initial letters. He was belatedly recognized in 1887 by the Royal Society with the award of the Davy Medal, but only after Mendeleev had more successfully introduced his table.
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Physics
In 1939, the journal Nature published a theoretical paper on nuclear fission. The term was coined by the authors Lise Meitner and Otto Fritsch, her nephew. They knew that when a uranium nucleus was struck by neutrons, barium was produced. Seeking an explanation, they used Bohr's "liquid drop" model of the nucleus to envision the neutron inducing oscillations in a uranium nucleus, which would occasionally stretch out into the shape of a dumbbell. Sometimes, the repulsive forces between the protons in the two bulbous ends would cause the narrow waist joining them to pinch off and leave two nuclei where before there had been one. They calculated the huge amounts of energy released. This was the basis for nuclear chain reaction.
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And here is a quote to bring hope and joy to you and your students.
I happen to feel that the degree of a person's intelligence is directly reflected by the number of conflicting attitudes she can bring to bear on the same topic. - Lisa Alther
