1""'" way (various versions have been given), Penzias and Wilson at Bell Lab: heard of Peebles' paper and of his theories about the Big Bang, When the 19 .•. Princeton and Bell groups exchanged information, they concluded tha the "noise" detected by the Bell radio antenna had JUSt the energ- expected for the radiation left over from the Big Bang, "Either we've seen the birth of the universe, or (as one astrophysical folk tale wouk have it) we've seen a pile of pigeon __ !" SOME ASTRONOMICAL Apparently the Nobel Prize authorities accepted the more scientific version of this conclusion, for Penzias and Wilson were awarded the Prize Serendipities in physics in 1978. Pulsars Jocelyn Bell and Anthony Hewish were not trying to discover pulsars in 1967. How could they? No one suspected that neutron stars emitted pulsed radio-frequency signals. At Cambridge University that summer, ,..,' Bell and Hewish were trying to measure the sizeof radio sources by seeing whether the sources "twinkled" as their radio waves passed through the interplanetary medium. But Bell noticed something unusual on the weekly extended charts that the Cambridge telescope produced: bursts of radiation appeared on The Big Bang the records each midnight. By the end of September she and Hewish had eliminated the possibility that these signals were terrestrial noise of any .•••./n1964 Arno Penzias and Robert Wilson, scientists at Bell Laborato- kind, and they noted that the bursts came earlier each night, just as stars ries in Holmdel, New Jersey, were modifying a radio antenna that had do, When the signals became very strong in November, the astronomers been used to receive signals from the early communication satellites. detected pulses of short duration and at very regular intervals. Bell then They intended to use the antenna for some rather prosaic studies on radio searched through reams of chart records, and found three more pulsars. signals from outer space. In preparation, they tried to eliminate all ter- When these findings were announced, explanations were sought and restrial sources of background radio signals. They evicted a pair of many were given, ranging from facetious ("communications from 'Little pigeons that were nesting in the horn-shaped antenna, and removed Green Men' in outer space") to serious (some astronomical object some- what was referred to in elegant scientific prose as "a white dielectric how creates the pulses). substance." After taking all such precautions, they found that there was An answer came from David Staelin and Edward Reifenstein at the still a residual radiation "noise", comparable to static on a radio. National Radio Astronomy Observatory in Green Bank, West Virginia, Astronomers had a theory that the universe started 15billion years who found a pulsar in the center of the Crab Nebula. Pulsars were said to ago with a tremendous explosion of highly condensed matter-the Big be neutron stars, the corpses left after a supernova explosion. Bang theory, as they euphemistically called it. This explosion produced a tremendous radiation of energy, which has been decreasing ever since. James Peebles at Princeton presented a paper about this theory at a Pluto's Moon scientific meeting at Johns Hopkins University in early 1965.In some An accident to a machine led to an astronomical discovery by James 120 .••.. Christy at the U.S. Naval Observatory in 1978. Christy was measuring the orbital characteristic of Pluto.To do so, he had placed a pho- •• tographic plate containing a picture of Pluto on an instrument called a Star Scan machine. When he did so, he noticed an elongation of the image of the planet. At first he assumed the bulge was an artifact and was 20 " going to discard the photograph. Luckily, however (as it turned out), the machine began to malfunction at that instant. Christy called in an electronics technician to repair the machine. The technician asked Christy to stand by while he made the repairs, because he thought he ACCIDENTAL might need Christy's help. During the hour required for the repair, Christy studied the photo- graph more carefully, and as a result he decided to look through the Medical archives for earlier pictures of the planet. The first one he found was marked "Pluto image. Elongated. Plate no good. Reject." His interest Discoveries now aroused, Christy searched through the archives and found six more pictures dated between 1965 and 1970 that showed the same bulge. His further studies proved that the bulge was a moon of the planet. If the Star Scan machine had not broken down when it did, he would not have discovered the new moon. Insulin "~889 in Strasbourg,Germany, while studying the function of the pancreas in digestion, Joseph von Mering and Oscar Minkowski removed the pancre~s"fr"'-om a dog. One day thereafter a laboratory assistant called their attention to.a swarm of flies around the urine from this dog. Curious about why the flies' ~ere attracted to the urine, they analyzed it and found it was loaded with sugar. Sugar in urine is a common sign of diabetes. ~ , Von Mering and Minkowski~ized that they were seeing for the first time evidence of the experimel'l~ production of diabetes in an animal. The fact that this animal had n~ancreas suggested a rela- tionship between that organ and diabetes. Von-,Mering and Minkowski subsequently proYeCfthat the pancreas produces aieo~etion that controls the use of sugar, and that lack of this secretion caus~efects in sugar metaboY,hat are exhibited as symptoms of diabetes, ~ M-anyattempts were made to isolate the secretion, with little"s,uccess utA 1921. Two researchers, Frederick G.Banting, a young Canadian "123 TT FH disease accounts for only a small fraction of coronary heart dis- ease cases. What is still not understood is why some humans have high-c cholesterol levels even though they do not have FH disease and do,n:~t 21 T ingest large amounts of cholesterol. There is certainly a genetic factor that accounss.jor the fact that some individuals are more prone to have :---. this problem tharr ..others. The studies of cell receptors in both humans and rabbits have givensomeanswers to this question and promise to give more. Basically, high cholesterel concentration in the blood stream is RAYS, "'.~ X due to two factors: one is the overproduction of cholesterol by the liver, the other is the underreception of cholesterol.... by the liver and adrenal Radioactivity, glands, which produce vital ster~jdal hormon~ fRm cholestero~. , Fortunately there now seems to be a possibility-of correcting this imbalance. A drug called cholestyramine has been found to increase the , I and number of LDL rece?t,o.rs and a new drug isolated from a mold.su~esses cholesterol synthesis 10 the LIver. The latter drug, mevmoltrt~(or Nuclear Fission lovastatin) wa~~discovered inde.pendently by Akiro Endo of the Sankya Drug Co, and by scientists at Merck Sharp and Oohme. Merck will ma~ket .~ Mevacor. Brown/ and Goldstein have suggested 'that the .' "two ug method" of lowg.i:-ngcholesterol levels may be worth trying for pe ons with criticallv high cholesterol concentrations. Discovery of X rays by Rontgen T In 1895 the German physicist Wilhelm Conrad Rontgen discovered X rays by accident. Rontgen was repeating experiments by other phys- icists in which electricity at high voltage was discharged through air or other gases in a partially evacuated glass tube. As early as 1858 it was found that the walls of the glass tube became phosphorescent during the I discharge. In 1878 Sir William Crookes described the "cathode rays" causing this phosphorescence as a "stream of molecules in flight," but we now know that cathode rays are actually' streams of electrons being emit- ted from the cathode, and the impact of these electrons on the walls of the glass tubes produces the phosphorescence. Neon signs, television tubes, and fluorescent light tubes are modern developments of these experiments. The insides of fluorescent tubes are coated with highly fluorescent materials to produce different colors and shades of light. In 1892 Heinrich Hertz demonstrated that cathode rays can pene- trate thin metallic foils. Two years later Philipp Lenard constructed dis- • 139 ,I·L. charge tubes having thin aluminum windows. These windows allowed the cathode rays to pass out of the tube where they could be detected by the light they produced on a screen of phosphorescent material (such screens were also used to detect ultraviolet light); but they were found to travel only two or three centimeters in the air at ordinary pressure outside the evacuated tube. Rontgen repeated some of these experiments to familiarize himself with the techniques. He then decided to see whether he could detect cathode rays issuing from an evacuated all-glass tube such as Crookes had used-that is, one with no thin aluminum window. No one had observed cathode rays under these conditions. Rontgen thought the reason for the failure might be that the strong phosphorescence of the cathode tube obscured the weak fluorescence of the detecting screen. To test this theory, he devised a black cardboard cover for the cathode tube. To determine the effectiveness of the shield, he then darkened the room and turned on the high voltage coil to energize the tube. Satisfied that his .•. William ROntgen, '''00 discotlered. black shield did indeed cover the tube and allowed no phosphorescent X rays light to escape, he was about to's~ off the coil and turn on the room lights so that he could position the phosphorescent screen at varying short distances from the vacuum tube. name he chose for them, X rays. (They have often been called Rontgen Just at that moment, however, he noticed a weak light shimmering from a point in the dark room more than a yard from the vacuum tube.