A common ingredient in many laundry detergents, optical bleaches (“fabric brighteners”) act by reflecting blue light.
The blue light combines with the yellow discoloration in a fabric to produce white light that makes the fabric seem brighter.
American physicist Murray Gell-Mann (b. 1929) named the quark in 1964. He took the name from James Joyce’s Finnegans Wake. A quark, a subatomic particle with a fractional electric charge, is believed by physicists to be the fundamental unit of matter.
It was brought on by the awarding of the 1932 Nobel Prize in physics to Werner Heisenberg for his uncertainty principle. The principle states that you cannot accurately know both the position and momentum of an atomic particle at the same time. Einstein believed that the principle made a mockery of cause and effect.
The highest elevation is Mount McKinley, Alaska, at 20,320 feet. The lowest is Death Valley, California, at 282 feet below sea level. The average elevation of the United States is 2,500 feet.
The skin on the foot or palm of the hand wrinkles when exposed to water because it expands. The thick, hardened layers of skin swell as water is retained.
Recent marriage rates have been fairly similar to what they were at the turn of the century. In 1900, the marriage rate was 9.3 per 1,000; in 1988, it was 9.7. The divorce rate, however, has changed drastically. In 1900, it was 0.7 per 1,000; in 1988, it was 4.8.
Connecticut was number one in 1987 with $20,980. At the bottom was Mississippi with $10,204. The average per-capita personal income in the United States as a whole was $15,340.