Topics in the News
Archaeology/Anthropology: Obsidian Dating
Stratigraphy and Seriation.
Archaeologists and anthropologists have always had difficulty trying to determine how old something is. At first, they used a technique called stratigraphy, based on the assumption that older things tend to be buried under newer things. A technique called seriation is a little more sophisticated. It assumes things get more complex over time. Radiocarbon dating was developed in the 1940s, but its use is limited to material that has been alive at some time.
Two new techniques to date old, nonliving material were developed in 1960: thermoluminescence and obsidian dating. Thermoluminescence can be used accurately to date rocks and pottery as far back as one thousand years. All rocks and pottery contain small amounts of radioactive elements. Over time the radioactive elements decay, giving off electrons in the process. These electrons get trapped within solid material. When a piece of rock or pot is heated to about 350 degrees Celsius, the trapped electrons are freed, and the material gives off a tiny bit of light. By detecting how much light is given off, the age of the material under study can be determined. This technique was developed by George C. Kennedy and Leon Knopoff at the University of California Institute of Geophysics in Los Angeles.
How Obsidian Ages....
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Searching for the Missing Link.
In the early 1960s British paleontologist Louis S. B. Leaky was searching in Kenya for the five-million-year-old missing link, an early ancestor of man from whom evolved one line of great apes and another line leading to man himself. A much older ancestor was discovered by Dr. Grant E. Meyer and Dr. Elwyn L. Simons of Yale's Peabody Museum.
A Skull Found.
The Yale expeditions started in 1961 in the Fayum desert of Egypt, about sixty miles south of Cairo. The area includes ancient lava flows. (There are no active volcanoes there now.) As wind and water eroded the lava, various remains were exposed. In the mid 1960s Meyer spotted a small bone sticking out of the lava about three hundred feet below the uppermost part of the lava flow. He carefully removed it, rock and all, and sent the entire formation back to Yale. There Simons carefully removed the rock and found an almost-intact small skull.
The skull belonged to an early ape ancestor, named Aegyptopithecus, the largest primate ever found in the Fayum region. Aegyptopithecus looked a little like modern lemurs but with different eye sockets. The most dramatic finding was the age of the skull, determined by potassium-argon dating. The skull was found to be between twenty-six and...
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Archaeology/Anthropology: Ancient Remains
Fig Tree Chert.
The oldest amino acids known to exist were found in 1968 in the Fig Tree Chert, a formation of Precambrian rock located near Barberton, South Africa. The rocks were dated as being 3.1 billion years old. Older rocks containing fossils have been found since then, but this was the oldest known at the time. The rocks, studied by J. William Schopf and Elso S. Barghoorn of Harvard and Keith A. Kvenovolden of the National Aeronautics and Space Administration (NASA), were known to contain what looked like fossils of algae and bacteria, some of the earliest forms of life. Using a process called chromotography to separate chemicals, the scientists found a series of amino acids. The Fig Tree Chert contained two free and seventeen combined amino acids.
The Essential Element of Life.
There are about twenty natural amino acids, and they link together to form proteins, the essential element of living organisms. Amino acids can form without any living creature making them, and the idea of spontaneously formed life molecules was a hot research topic in the 1960s. Several labs were showing that conditions on the early earth were just right for forming amino acids. The challenge facing the scientists working on the Fig Tree Chert was to prove the chemicals they found were originally in living organisms.
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Astronomy: Radio, X-ray, and Infrared
Radio, Infrared, and X-ray Astonomy.
Radio astronomers of the 1960s were as interested in sending out radio waves as they were in receiving them. In 1964 the radio dish at Arecibo in Puerto Rico was used this way. It bounced radar off planets in the solar system and detected the returning waves, allowing astronomers to make more-accurate measurements of orbits around the sun, distances from Earth, tilts of the axes of the planets, and speeds of rotation on the axes than had been possible before.
Three groups of astronomers used radar during the decade to map Venus, which is covered by clouds, so its surface is not visible to ordinary telescopes. Cornell astronomers used the Arecibo observatory. The Jet Propulsion Laboratory (JPL) in Pasadena, California, and Lincoln Laboratory at the Massachusetts Institute of Technology (MIT) bounced radar off the "veiled planet." The Cornell group found mountains on Venus. Rough spots (such as mountains) scattered the radar more than smooth spots. The MIT group used the scatter technique to look at surface features over smaller areas. The JPL group calculated the rotation of Venus on its axis. It was in the opposite direction from all the other planets.
The Development of VLBI Technology.
Perhaps the most important development of the...
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Astronomy: Pulsars, Quasars, Cosmic Masers
One of the major discoveries of the 1960s was the quasar, short for quasi-stellar object. The first identified quasar was 3C-48. The "3C" stands for Third Cambridge Catalog of Radio Sources, a catalogue used by radio astronomers. Allan R. Sandage of Mount Wilson and Mount Palomar Observatories in California reported it at the 107th meeting of the American Astronomical Society in New York in 1960. Employing two mobile ninety-foot parabolic radio antennae, Sandage used a technique called triangulation to locate the object. Thomas A. Matthaus had noted variable radio emissions from a small area and predicted a visible star there. Sandage found the object in the predicted location. But 3C-48 did not act much like a star. It was extremely hot (over one hundred thousand degrees Celsius). Sandage looked at the spectrum of the area (spectral lines tell astronomers what elements are present in and around a star). He found no hydrogen, which is present in essentially all stars. Instead of hydrogen, Sandage found 3C-48 contained calcium ions (charged calcium), helium, helium ions, and strange ions of oxygen. He suspected it could be a star surrounded by high-energy electrons in a magnetic field moving at the speed of light. This might explain how it gave off radio and light waves. Another possibility was that it was the remnant of a supernova.
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Astronomy: Project Ozma—Will They Hear Us?
Search for Life on Other Worlds.
In the early 1960s changes in astronomy brought about Project Ozma—a search for other worlds with intelligent life—named after the princess of L. Frank Baum's Land of Oz. Dr. Frank Drake was the chief astronomer involved. The government sponsored Drake in Project Ozma, through the National Science Foundation (which owned the observatory), to make an initial search for life on other worlds. He worked at the National Radio Astronomy Observatory at Deer Creek Valley in West Virginia, where the local population referred to Drake's research as "Project Little Green Men." Drake sent and listened for radio-wave messages, hoping to make contact with extraterrestials. He was limited by the range of the radio telescope. Though he could listen to close stars, it was impossible to search the whole universe.
Narrowing the Search.
Dr. Otto Struve, Russian-born director of the observatory, pointed out some ways to narrow the search. Double and triple stars could be eliminated. Planets going around such multiple-star systems would be subjected to extremes of hot and cold that would not support life. Dr. Guiseppe Cocconi and Dr. Philip Morrison of Cornell suggested that the wave-length to listen to would be twenty-one centimeters long, the wavelength of hydrogen in interstellar space. It is easy to receive this...
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Astronomy: The Sound of the Big Bang
Measuring Radio Signals from Hydrogen.
In 1961 German-American physicist Arno A. Penzias completed work on his Ph.D., studying the use of masers to amplify radio signals, and began work at Bell Laboratories with Robert W. Wilson measuring radio signals from hydrogen in space. They had access there to the world's most sensitive radio telescope, a six-meter horn antenna used to send and receive signals from the passive Echo satellite.
A Constant Noise.
In 1961 the Echo chief engineer E. A. Ohm noted electronic noise in this antenna carefully measured at three kelvins. Penzias and Wilson tried to eliminate the noise without success. They cleaned a family of birds out of the horn and eliminated mechanical vibrations, but a constant three kelvins of noise was always there.
The Big Bang.
Finally, they concluded that the noise came from space itself, from all directions in the microwave region. They were drawn to the work of P. J. Peebles and Robert H. Dicke of Princeton University, who suggested that all the elements in the universe formed in a giant explosion they called the big bang. After the big bang leftover energy was still present. Peebles said this should be detected as "background radiation" of less than ten kelvins. Peebles had suggested an oscillating universe....
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Biology: Molecular Revolution
Cracking the Code for RNA.
Marshall W. Nirenberg, working at the National Institutes of Health in Bethesda, Maryland, in 1961, performed brilliant experiments in biochemistry. These led to the molecular revolution that has continued since his work, done with his German postgraduate fellow J. H. Matthaei, was reported at the Fifth International Congress of Biochemistry in Moscow. In 1953 the physicist George Gamow worked out some basics of the code. A single ribonucleic acid (RNA) could only code for four possible amino acids. Pairs of nucleic acids could code for sixteen possibilities. Since there are about twenty amino acids, at least three nucleic acids in RNA must code for each amino acid in proteins. But Gamow made a mistake when he suggested that overlapping sequences of RNA provided the code for different amino acids. Nirenberg and Matthaei corrected him and broke the RNA code.
Creating Artificial Protein.
They removed various chemicals required by cells to make proteins from a sample of Escherichia coli (E. coli) bacteria and put the chemicals in a test tube with no live cells left. Then the scientists added amino acids made with radioactive carbon atoms so they could measure small amounts of protein produced if they came up with the right combination of amino acids. Nirenberg made artificial RNA and successfully produced...
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Biology: The First Gene
In 1969 the first gene was isolated. Genes are the basis of heredity, carried by DNA. The genetic code had been broken, so science knew how DNA worked. But the process for isolating genes was elusive. Dr. Jonathan Beckwith of Harvard solved the problem using simple viruses that infected the intestinal bacterium E. coli. Two viruses were used, both of which tended to incorporate one of the host's genes after infecting it. Each virus could incorporate different host genes, but both these viruses took the "lac" gene, which lets the bacterium eat lactose, a milk sugar.
DNA Strands Separated, Rejoined.
Beckwith removed the protein shell from both viruses, and heated their DNA separately, causing its two strands to separate. He then mixed the two types of DNA and slowly cooled them. Usually, DNA being cooled this way will seek its complementary strand to rejoin. In Beckwith's experiment DNA from the one virus attached to the complimentary DNA from the other in the only place they fit—the lac gene. Beckwith chemically removed the excess, leaving copies of the complete lac gene intact.
"An Elegant Triumph," Time, 94 (5 December 1969): 80.
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Biology: Dolphin Communication
The Complex Brain of the Dolphin.
During the 1960s scientists began studying how the remarkable dolphin communicates. The dolphin is a mammal, not a fish, in the order Cetacea, which also includes whales. These mammals breathe with lungs, nurse their young, have extremely complex brains, and are otherwise similar to land mammals. In 1960 the neurophysiologist Dr. John C. Lilly reported on his four years of talking to bottle-nosed dolphins (Tursiops truncatas) at a U.S. Navy facility near Charlotte Amalie in the Virgin Islands. He implanted electrodes in the brains of thirty dolphins and found a "pleasure center": stimulating the electrode implanted there caused the dolphins to have wide eyes and look like they were smiling. They would also change their behavior to make Lilly stimulate the electrodes more often. Similar experiments had been performed on chimpanzees, and the dolphins learned much more quickly.
Sending a Distress Signal.
Lilly also put a partly paralyzed dolphin in a pool with other dolphins. The paralyzed dolphin could not reach the surface to breathe, and so it would die without help. Other dolphins learned of their new neighbor's distress and helped him reach the surface and stay there, talking to each other in frequencies above the range of human hearing. When Lilly played back the tape of their talking, at...
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Biology: Primordial Soup
The Soup of Life.
Primordial soup was the chemical mixture thought to represent the atmosphere of the early Earth, composed of ammonia, hydrogen, methane gas, and water vapor. It is a chemically rich mixture but not apparently conducive to living things. Even before 1960 scientists began to show that primordial soup could produce the types of chemicals of which life is made, but a 1960 report by Juan Oro in Biochemical and Biophysical Research Communications made an important advance in the subject.
Cooking the Soup.
It had already been found that amino acids formed in primordial soup by performing experiments using electric sparks as simulated lightning. Stanley Miller had shown that hydrogen cyanide (HCN) was an important intermediate chemical in forming amino acids, which make up proteins. The question was, How did the all-important DNA or RNA required for life form? Oro took HCN gas and bubbled it into ammonia to form ammonium cyanide, which then reacted with itself. Oro reasoned that the atmosphere of the early Earth was much hotter than it is now, so he heated the chemical mess overnight and separated the resulting compounds using a process called paper chromatography. One product was adenine, required for DNA and RNA.
Creating a Dimer.
As Oro continued his work, other...
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Chemistry: Not So Noble Anymore
The noble gases, including helium, neon, and xenon, do not normally form compounds with other chemicals. Their atoms have enough electrons not to require sharing with or borrowing from other atoms.
Making Compounds from Noble Gases.
In 1962 the American chemist Neil Bartlett was working in Canada when the idea struck him that it was possible to make compounds from noble gases. He knew that, in the complex chemical oxygen-platinum-hexaflouride, oxygen acts as if it has a positive charge (O2+) and the platinum and fluoride combine and act negatively charged (PtF6-). Bartlett knew it took a lot of energy to remove an (negatively charged) electron from oxygen and make it act positively charged, about the same amount of energy required to remove an electron from xenon. But PtF6- was the best oxidizer (electron remover) known.
Bartlett used the PtF6- with xenon and formed a new compound. Xenon-platinum-hexaflouride (XePtF6) is a yellow-orange powder so stable it does not decompose at room temperature in regular room air.
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The study of man-made elements was critical in World War II. There was a need for a radioactive material to use in an atomic weapon, but not for material so radioactive it would disintegrate before the bomb could be made and dropped. The Radiation Laboratory (later the Lawrence Berkeley Lab) at the University of California, Berkeley, succeeded by producing plutonium. With a half-life (the time it takes for half of it to undergo radioactive decay) of twenty-four thousand years it allowed plenty of time to make a bomb. Plutonium, element 94 on the periodic table of the elements, was one of ten man-made elements produced by the Radiation Laboratory. The Berkeley based scientists produced all but one of the man-made elements (from 93 to 103). Swedish scientists made element 102, nobelium.
A New Element.
Element 103, lawrencium, was formed in 1961. The Berkeley group took some nickel foil, coated it with a thin layer of californium (another man-made element, number 98), placed it in a helium chamber, then, with a heavy-ion linear accelerator, threw nuclei of boron 10 and boron 11 at the foil at great speeds. When the boron nuclei hit the californium, neutrons were lost, and lawrencium was formed.
A Short Life.
Its chemical properties were difficult to determine, though, because...
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Computer Science: Basic Knowledge
An Awkward System.
At the beginning of the 1960s, computers were expensive and difficult to operate. Because of the expense, most computers served up information to multiple clients or users from a central location. Information was input on machines capable only of punching holes in cards. The computer processed the information recorded on the cards and ran programs written by highly trained programmers. Reports were generated and returned in the form of hard copy to whomever requested them. It was an awkward system.
Making Computers Practical.
In the early 1960s John Kemeny, chairman of mathematics at Dartmouth University, started working with Thomas Kurtz, director of Dartmouth's Kiewit Computer Center, on ways to make computer use practical for most of their general college students, not just the engineering, math, and physics graduate students. They got a grant from the National Science Foundation to buy equipment, and in 1964 General Electric sent them two new computers, as well as all the paraphernalia required to make them work. But without the instructions on how to hook them up Kemeny, Kurtz, and their students figured out a hookup scheme on their own. They developed a new concept of "master" and "slave" computers. The various teletype terminals fed into the master, which directed the slave to make the necessary calculations....
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Computer Science: When the Chips are Down
An Electronics Revolution.
During the 1960s the integrated circuit (IC) created a revolution in electronics. Previously circuit boards that ran electronic devices had to be big enough to hold components such as vacuum tubes, capacitors, and resistors. Then vacuum tubes were replaced by transistors, resulting in saving some space. But once wonder materials called semiconductors could be fabricated successfully, hundreds or thousands of complete individual components could be incorporated on a single one-inch-square silicon wafer. Computers the size of a room could now be emulated by machines the size of a television, and radios the size of a loaf of bread could be reduced to the size of a candy bar.
The first user of these chemically etched integrated circuits was the military. It did not take long to figure out that ICs could be used in consumer products as well. Television sets still had vacuum tubes in 1960, but most black-and-white sets were transistorized by the mid 1960s. Then there was a television revolution. In the mid 1960s Congress passed a law saying all TVs had to include UHF (ultrahigh frequency) tuners in addition to the standard thirteen channels. Manufacturers turned to ICs. ICs had to be custom-made for each application. The cost of one was enormous, but a truck-load did not cost much more, and so for...
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Earth Sciences: Geothermal Power
The Earth's Heat.
Inside of the Earth is a giant source of heat called geothermal power that can be used to run electrical generators. One of the first geothermal power units was built in Larderello, Italy, in the early 1900s. Until 1960 there were not any in the United States because it cost too much to get to the heat source and carry the heat to the surface in usable form.
The Earth's crust is about twenty miles thick, but it is not the same thickness everywhere. Under the crust is magma, and cracks in the crust allow magma to come close to the surface in some places. Magma is about 10 percent water, which works its way down from the surface. When the water works its way back through cracks in the crust, it forms fumaroles—geysers with superheated steam. Normally water only reaches the temperature of its boiling point. Once it turns to steam, its temperature does not change even if heated more. But high pressure causes the steam to superheat to a temperature higher than the boiling point. This superheated steam can be used as a steady source of power to turn a generator.
Electricity from Geysers.
In the valley of Big Sulphur Creek, seventy miles north of San Francisco, there are geysers. The magma reaches to about three hundred to four hundred feet below the...
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A-Bombs for Peace.
Throughout the 1960s, the Atomic Energy Commission (AEC) pursued a series of projects called the Plowshares Program, an attempt to find peaceful uses for atomic bombs. In 1961 the first peaceful nuclear blast occurred. It was detonated underground twenty-five miles from New Mexico's Carlsbad caverns. The purpose of Project Gnome was to conduct various scientific experiments; the explosion was expected to supply a vast underground salt cavern and to produce steam for generating electricity. The blast occurred prematurely, and the explosion knocked the top off the underground chamber, ruining the steam "teakettle" and letting clouds of radioactive waste into the atmosphere. Gophers chewed through cables connecting some of the scientific instruments. Nonetheless, the scientists present declared Project Gnome a great success.
Project Sloop, a government and industry partnership, took place near Safford, Arizona, where two billion tons of rock containing .4 percent copper lay under five hundred feet of volcanic rock. Project Sloop, designed to get the copper out, cost $13 million over thirty months. Sloop required drilling a twenty-inch shaft twelve hundred feet straight down. Then a twenty-kiloton nuclear device was exploded, leaving a two-hundred-foot-diameter cavity at the bottom. The rock inside melted...
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Earth Sciences: The Greenhouse Effect
The Theory of Arrhenius.
The first suggestion that burning fossil fuels could warm the Earth's atmosphere was in 1896 by Svante Arrhenius, the famous chemist. Few people believed him. The atmosphere was thought to be so big and so stable that it could not possibly be affected by small fires.
In 1964 Syukuro Manabe and Richard Wetherald, two American climatologists, developed a computer model of the atmosphere to predict how water vapor and carbon dioxide (CO2, which is produced by burning carbon fuel) would affect the climate. The effect they found was global warming, popularly known as the greenhouse effect.
Carbon Dioxide and Infrared Radiation.
The normal carbon dioxide in the atmosphere has several specific effects, one of which is to hold the heat from the sun. Water vapor in the atmosphere blocks most infrared radiation from reaching the surface of the Earth. When visible sunlight reaches the surface, the Earth absorbs it. Part of the energy absorbed is released by the ground as infrared radiation, which is not seen, but felt as heat. The carbon dioxide in the atmosphere prevents this infrared radiation from escaping. The result is heating of the atmosphere.
The Fossil Fuel-CO2 Connection.
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Oceanography: Seafloor Spreading
In 1960 the theory of plate tectonics was given a huge boost by the oceanographer Harry H. Hess, who demonstrated his theory that the seafloor was
The easiest way to prove Hess's theory was to drill a hole in the seafloor to pierce the interface of the crust and mantle, called the Mohorovicic Discontinuity, after the Yugoslavian seismologist who discovered it. Mohorovicic was shortened by scientists to Moho; thus the...
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On 23 January 1960 the bathyscaphe Trieste, a manned vehicle designed to dive into deep seas, dove to about 37,000 feet in the Mariana Trench of the Pacific Ocean. Inside were twenty-eight-year-old navy lieutenant Don Walsh and thirty-seven-year-old Frenchman Jacques Piccard. Piccard's father designed and built the Trieste in Italy for the U.S. Navy. The dive took four hours and forty-eight minutes; the Trieste spent half an hour at the bottom, where the hull withstood pressures of over 17,000 pounds per square inch.
Trieste dove 4 feet per second to 27,000 feet. The first part of the dive was smooth compared to the rough seas above. Then Trieste hit a thermocline, where water temperatures drop sharply at a certain depth, causing the relative weight of the craft to increase. There were thermoclines at 250 feet and again about 400 feet. The second was thick and caused the craft to rock. After less than 1,000 feet the thermoclines were gone, but the passenger compartment got cold. All light from the surface was essentially gone at this depth. The passengers had a small compartment to share. They lost radio-telephone contact at 15,000 feet. After 27,000 feet the Trieste dumped some ballast and slowed to 2 feet per second. At 36,000 feet they slowed to .5 foot per...
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Oceanography: Sealab and Friends
There were Sealab projects in the 1960s numbered I, II, and III. The Sealabs were submarines of sorts equipped for scientific study. Some scientists thought that people could live and work underwater for long periods, and the Sealab project was an attempt to find out what problems such conditions would pose. The Sealabs were underwater experimental chambers where people would stay submerged for days at a time to work in and study the oceans. Sealab I submerged off Bermuda in 1964, and four people stayed down for nine days at 192 feet. This was a warm ocean area. The next step was Sealab II, taken to a cold ocean region.
Sealab II cost $850,000, a phenomenal price in its day. It was a 12-by-57-foot cylinder made of steel and containing life-support equipment and scientific research instruments. The "submarine" was attached to its support barge on the surface by an "umbilical" cable. Supplies could be lowered to the Sealab by pressurized containers. It also had an escape capsule for use in emergencies. The umbilical cable allowed closed-circuit phone and television communications with the support barge.
Problems with Pressure.
Sealab worked in high pressures under water, creating some problems for the occupants. Matches will not...
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Physics: Proving Einstein Right
The Einstein Shift.
Albert Einstein was a theoretical physicist. He used mathematics to solve problems and express new ideas, but he did not perform experiments to check his theories. Experimental work was left to others. Einstein's brillliant special theory of relativity in 1905 and general theory of relativity in 1916 proposed that space was composed of the three dimensions (length, width, and depth) plus time. The path of light moving through a gravitational field would be curved, he theorized, altering the perception of time. Stars are massive bodies, so big that space-time wraps around them.
As light travels from a distant star toward Earth, it bends as it goes around a nearer star in its path. This is because the nearer star is so massive its gravitational field bends light as it travels, causing the light to lose some energy in the process and thus making it appear redder than it really is. This bending of light is called the Einstein Shift, and it is difficult to detect because the movements of stars themselves cause reddening of the light they give off.
Examining Sirius B.
In 1925 the American astronomer Walter S. Adams solved the technical problem of detecting the Einstein Shift. He used a white dwarf star called Sirius B., an extremely dense body with high...
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Physics: What Does It Antimatter?
One of the predictions of quantum theory, the branch of physics that deals with the smallest elements in the universe, was the existence of some seventeen basic particles of matter and antimatter. One fundamental bit of antimatter, the infamous anti-xi-zero, was difficult to identify for several reasons, chief among them being that it has no charge. In the usual bubble chambers where particles are studied, anti-xi-zero would leave no track, even if it were present. Physicists faced the dual challenge of finding the right combinations of particles to combine in order to produce it as a residual and of recognizing it when it was found. They also did not know what properties anti-xi-zero should have, such as how it would affect other atoms or particles during collisions.
Experimenters from Yale University and from Brookhaven National Laboratory started a nearly two-year search for anti-xi-zero in September 1961. They used the Brookhaven alternating gradient synchrotron to hurl antiprotons at liquid hydrogen nuclei in a twenty-inch bubble chamber. For a brief period, the particles produced phenomenal energy and new particles that were tracked in the bubble chamber and photogaphed for review later. The thirteen experimenters had to look over three hundred thousand pictures in great detail to find the...
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Physics: Irradiate for Safety
Irradiated Food, Healthy or Harmful?
The U.S. government in the late 1960s debated the use of radiation to kill all or most of the bacteria that cause food spoilage. The army was interested in irradiating food because during war it is hard to keep providing the troops with fresh food. Irradiation makes this task much easier. The AEC was also interested in this peaceful use of radioactivity. The army and the AEC contracted with a company called Irradiated Foods, Incorporated, to provide irradiated ham that was sterilized before it was canned and could then be kept indefinitely without refrigeration. But the Food and Drug Administration (FDA) refused to approve irradiated ham for human consumption. They based their objection on studies showing that animals eating irradiated food died sooner, had fewer babies, and even weighed less than animals that ate regular food.
Studies and Results.
The army and the AEC had studied irradiated food for ten years. Dr. Edward S. Josephson, associate director of the Food Irradiation Laboratory at the army's Natick, Massachusetts, center, argued that the radiation technique had been refined and improved since the animal studies the FDA was concerned about were conducted. The best tested food use for irradiation was in seed potatoes. Dr. George Pigott of the University of Washington in Seattle used cobalt 60...
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The Search for a Laser.
Once Charles H. Townes developed the maser in the 1950s, the search was on for a similar instrument that used light. Lasers and masers work on the same principle. A core of atoms are excited to a high energy state. They return to their normal energy state by releasing energy at a single, "coherent" frequency. In masers this is microwave or radio energy; in lasers it is light energy.
The First Laser.
In 1960 Theodore H. Maiman at the Hughes Research Laboratory used a synthetic ruby to produce the first laser. A ruby is composed of crystals of aluminum oxide with a trace of chromium, which provides its color. The ruby allows the atoms to be excited long enough to accumulate and emit their energy packets all at once. Amplifying the light effectively is an engineering problem. While various atoms are excited and release energy coherently, some will release energy out of phase. Maiman figured out how to get rid of these out-of-phase energy packets.
His ruby was about the same diameter as a pencil and four centimeters long. The ends were polished flat to form planes parallel to within about one-millionth of a centimeter of each other. Then they were coated with silver to act as mirrors that would reflect light beams back and forth between them. Any other...
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The Space Program: Project Mercury
The early space travelers were almost all male and were all in the military. Americans called their spacemen astronauts; the Soviets called theirs cosmonauts. The United States called its first manned space flight program Project Mercury; the first Soviet program was called Project Vostok.
The First Men in Space.
Yuri A. Gagarin, twenty-seven years old, was the first human in outer space. He was launched in the Vostok 1 space vehicle aboard a modified SS-6 Sapwood ballistic missile. He reached a maximum altitude of 203 miles above Earth and orbited Earth once in his 108-minute flight. The Soviets proved that a man could withstand the forces of lift-off and the space-capsule environment during a short space flight. On 5 May 1961 Alan Shepard, Jr., a commander in the navy, was launched into space in his Project Mercury space capsule Freedom 7. In military fashion he was allowed to name his space vehicle. (NASA stopped this practice in Project Gemini, which followed Project Mercury.) He was launched aboard a Redstone rocket in a fifteen-minute, twenty-eight-second flight that was less than a full Earth orbit. He reached a maximum of 116 miles above Earth, and his maximum speed was 5,180 miles per hour. For his trip into space, he received military flight pay of $14.38.
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The Space Program: Project Gemini
Working toward Kennedy's Goal.
President John F. Kennedy had told Congress in May 1961 that the United States should have a goal of, by the end of the decade, landing a man on the Moon and returning him safely. After President Kennedy was assassinated in 1963, NASA was expected to achieve this goal in Kennedy's honor. While Project Mercury made impressive progress, the United States was still a long way from a lunar landing. The next step in the stage, Project Gemini, named after the "twin" sign in astrology, involved putting two men at a time in space.
Soviets Play a Dangerous Game.
To beat the Americans again in the space race, the Soviets played a dangerous game with Voskhod 1, launched on 12 October 1964. They took a one-man Vostok capsule, removed the ejection seat and safety equipment, and crammed three men into the tiny capsule without protective space suits. Two of the crew had hardly any training for space flight. The flight was successful but reckless. Soviet premier Nikita Khrushchev was ousted from power while talking to the cosmonauts, and his publicity stunt may have been part of the reason for his downfall. Had anything gone wrong, Voskhod 1 would have been disastrous publicity for the Soviets rather than being the first three-man flight.
Walk and Rendezvous.
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The Space Program:Project Apollo
The Soviets and Americans both started new projects in 1967 in the race to be first on the Moon. The Americans initiated Project Apollo; the Soviets, Project Soyuz. Both began with horrible disasters that set each country's space program back a year and a half. The U.S. crew of Grissom, Ed White, and Roger Chaffee were testing the new Apollo systems on the ground in January 1967. On 27 January the three were inside the spacecraft that was going to be Apollo 1 breathing pure oxygen. Suddenly ground control noticed they had elevated heart rates. They were heard to say, "fire in the spacecraft" and "get us out of here." Then there was a burst of flame seen from outside. It took six minutes for technicians and workers to open the hatch. By that time the three astronauts were dead. The interior of the craft was estimated to have reached 1,000 degrees Fahrenheit.
The investigation of the accident reported that it could have been prevented. After Grissom's Mercury capsule sank, the hatches on space-craft were bolted shut to prevent premature opening in the ocean. An electrical spark, caused by broken insulation on electrical wires run under a close-fitting door, started the fire, which burned furiously in the pure oxygen atmosphere. There were waste rags in the craft, and flammable plastics were not...
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The Space Program: Unmanned Space Exploration
Many people have felt that sending astronauts into space has always been an expensive publicity stunt. They require costly equipment, training, and safety measures, yet unmanned satellites have proven just as useful at gathering scientific data. A major breakthrough in the use of unmanned satellites was the launching of Echo 1 on 2 August 1960. Echo 1 was a giant balloon designed by Bell Laboratories and NASA working in partnership. The balloon material was squeezed into a payload and launched into space. Once there, a chemical was used to inflate the balloon, made from a plastic film and covered with an aluminum skin. Echo also had two tiny radio transmitters so it could be tracked. (Actually, as it was large and in a low orbit, it could be seen from Earth). Echo was a "passive" communications satellite. When it was in the right place, radio-wave messages could be bounced off it and directed to another location.
Telstar 1 and Relay 1.
More important were the 1962 launches of Telstar I (Bell Telephone/AT&T) and Relay 1 (RCA), both active communications satellites. Telstar was a three-foot-diameter ball. It had solar cells to convert light to electricity to power it, and due to miniaturization of electronic parts it weighed only 170 pounds. Telstar...
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More Miles to the Gallon.
A nuclear-powered navy vessel can go a long way between stops for fuel. That is why Adm. Hyman Rickover pushed so hard to develop the nuclear navy and why the country was willing to pay so much to get it.
The USS Washington.
The nuclear-powered submarine USS Washington was built by the General Dynamics Corporation's Electric Boat Division in Croton, Connecticut, and launched from the Charleston, South Carolina, shipyard in the fall of 1960. The Washington had amissile compartment containing sixteen seven-foot tubes in a 100-foot area, each holding a Polaris missile, and could stay submerged sixty days at a time. It could go three years without stopping to refuel. The sub had two crews (the "blue" and the "gold"), each consisting of ten officers and ninety enlisted men. Each crew spent sixty days on patrol. The sub's first voyage covered 1,200 miles over three months.
Run Silent, Run Deep.
One of the advantages of the Washington was it could stay submerged and hidden just about anywhere. If war struck, the Washington would strike and then move silently to a new location. The trick was knowing where the sub was at all times without having to surface and give its location away. For this it had a periscope system that could see...
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Gell-Mann, Murray 1929-
Early Life and Education.
Murray Gell-Mann was born in New York City on 15 September 1929. His parents were immigrants from Austria. Gell-Mann wanted to study archaeology, but his father wanted him to enter a more practical field such as engineering. They compromised, and he majored in physics. Gell-Mann received his B.S. from Yale in 1948 and his Ph.D. from MIT in 1951.
Working with Einstein.
After MIT he worked for a year at the Institute for Advanced Study in Princeton with Albert Einstein, at the University of Chicago from 1952 to 1955, and then at the California Institute of Technology. He became a full professor while in his mid twenties, only four years after receiving his Ph.D.
Work with Atomic and Subatomic Particles.
Some of his greatest work was done with fellow Nobel laureate Richard P. Feynman, with whom he studied the theory of weak interactions, which explains spontaneous radioactive decay in the nuclei of atoms. He also described "strangeness" (named from a quote by Francis Bacon), which explains mathematically how newfound (in 1953) subatomic particles interact.
A Theory of Subatomic Families.
In 1961 Gell-Mann developed the theory of the "eightfold way" (named after a Buddhist...
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Grissom, Virgil I. ("Gus") 1926-1967
Second American in Space.
Virgil I. Grissom was a key figure in the United States' manned space-flight program. He was among the seven original astronaut trainees for Project Mercury in 1959, and he became the second American to go into space when the Liberty Bell 7 was launched on 21 July 1961 (Alan B. Shepard had been the first on 5 May). Though Grissom's flight exceeded the distance and speed of Shepard's, it experienced a glitch after splashdown when the escape hatch blew prematurely and the capsule filled with water and sank. Grissom managed to escape but was somewhat shaken by the experience.
Soon thereafter, NASA presented Grissom with its Distinguished Service Medal, and he, along with Shepard, received his astronaut's wings on 7 December 1961. On 15 July 1962 Grissom was promoted to the rank of major, and he received further distinction on 19 July 1962 when he was awarded the first General Thomas D. White Trophy for being "The Air Force member who has made the most outstanding contribution to the nation's progress in aerospace."
Grissom helped design and construct the spacecraft of Project Gemini, a series of missions designed as an intermediate step between Project Mercury and the Apollo Moon project. On...
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Hess, Harry H. 1906-1969
The plate tectonics theory, basic to oceanography and geology today, was accepted because of the work of Harry H. Hess on seafloor spreading. Once seafloor spreading was shown to occur, Hess concluded that continents drift over time, the result of continental plates of the Earth's crust moving laterally around the planet. This is the theory of plate tectonics, which was developed over a period of some fifty years.
German scientist and explorer Alfred L. Wegener first proposed continental displacement (or drift) in 1924 to explain how various parts of the continents seemed to fit into each other like pieces of a jigsaw puzzle. He thought they were all connected once and drifted apart, but he could not prove his theory.
Then the midocean ridges were found. When Harry Hess was a navy captain of a Pacific attack transport, he was intrigued by flat-topped mountains under water identified by his sonar equipment. Hess named these mountains guyots, after Arnold Guyot, a Swiss-American who was Princeton's first professor of geology. In the 1950s guyots were found to be part of the Earth's mantle just below the surface. The mantle moves up in the ridges and pushes the seabed to either side. Hess said it...
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Kornberg, Arthur 1918-
Arthur Kornberg won the Nobel Prize for discovering the enzyme DNA polymerase, the substance that reproduces DNA in cells. Kornberg was able to produce DNA in the test tube in 1959, but it was not biologically active. The DNA he produced was based on a template from any natural DNA source. The DNA polymerase was from E. coli a common bacterium in the human intestine that could copy a DNA template from any organism.
Methods to determine the sequence of bases in DNA were not exact in the 1960s, and Kornberg's test-tube DNA was not an exact copy such as living cells must produce. One of the problems of producing an active DNA was getting a good template. The E. coli DNA is four million base pairs long. It was almost impossible to get a good sample of DNA this long. So Kornberg used the much smaller DNA of a virus instead. The virus he chose was Phi X174, which infects bacteria (a bacteriophage). It has a single strand of DNA fifty-five hundred bases long and comes in a circle. It only contains about eleven genes. That made it easier to purify without breaking it up. It was known that even minor mutations of the DNA made the virus lose its ability to infect bacteria.
Scientists Playing God.
Kornberg worked with...
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Weber, Joseph 1919
Einstein's Concept of Gravity.
Einstein's general theory of relativity predicted that huge bodies accelerating in space should give off gravity in waves. These gravity waves would travel at the speed of light. Physicists believed Einstein, but until University of Maryland physicist Joseph Weber published the results of a ten-year experiment in 1968, these waves had not been proven to exist.
Weber posited that gravity waves should not be expected to be strong, so he would need a sensitive detector. But then he would need a way to eliminate the interference—Earth tremors, passing cosmic rays, electromagnetic radiation, and even atomic decay of naturally radioactive materials within the detector itself. He concluded that two detectors fairly far apart would both be influenced by all those interfering factors, but not at the same time. So if two detectors recorded activity at the same time, it was probably gravity waves, particularly if the simultaneous activity were recorded repeatedly.
Dr. Weber made two detectors, large aluminum cylinders one and a half tons each, designed to respond to 1660-cycle radiation, the frequency expected from gravity waves produced by pulsars. One detector was set up at the University of...
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People in the News
In 1969 Jonathan Beckwith, leading a team of Harvard Medical School scientists, isolated and photographed a gene for the first time.
Chemist Kenneth Conrow in 1967 employed a computer to assist in the complex task of naming new chemical compounds he was developing; in the process he found twenty-nine compounds that had been incorrectly named in official publications.
Astronaut Leroy Gordon Cooper, Jr., made the sixth and last of the Project Mercury flights in May 1963, manually landing the craft after it developed electrical problems.
Archaeologist Richard Daugherty and geologist Roald Fryxell of Washington State University announced in 1968 the discovery in southern Washington of the oldest human remains found in the Western Hemi-sphere.
In 1960 C. H. W. Hirs and colleagues at the Rockefeller Institute and the Brooklyn National Laboratory provided the first delineation of the structure of an enzyme.
William Hayward Pickering led a team of scientists who sent the unmanned spacecraft Ranger 7 to the Moon in 1964; it sent back approximately 4,000 close-range photographs of the Moon's surface.
Maarten Schmidt announced in 1965 the discovery of the most distant object known, the quasar 3C 9.
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NOBEL PRIZE WINNERS
During the 1960s there were fifty-six recipients of Nobel Prizes in the sciences, and half of them were Americans. The Nobel Prize is widely considered to be the highest honor bestowed uopn scientists and signifies worldwide recognition of their work.
1960: Physics, Donald Glaser, Chemistry, Willard F. Libby
1961: Physics, Robert Hofstadter; Chemistry, Melvin Calvin; Medicine and/or Physiology, Georg von Bekesy
1962: Physiology and/or Medicine, James D. Watson
1963: Physics, Eugene P. Wigner and Maria Goeppert-Mayer
1964: Physiology and/or Medicine, Konrad E. Bloch; Physics, Charles H. Townes
1965: Physics, Richard P. Feynman and Julian S. Schwinger; Chemistry, Robert B. Woodward
1966: Physiology and/or Medicine, Francis Peyton Rous and Charles B. Huggins; Chemistry, Robert S. Mulliken
1967: Physiology and/or Medicine, Haidan Keffer Hart-line; Physiology and/or Medicine, George Wald; Physics, Hans A. Bethe
1968: Physiology and/or Medicine, Robert W. Holley, H. Gobind Khorana, and Marshall W. Nirenberg; Physics,...
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Roy Chapman Andrews, 76, naturalist, former director of the American Museum of Natural History, 11 March 1960.
Walter Baade, 67, astronomer, first to describe supernovas, 25 June 1960.
Charles William Beebe, 84, biologist and explorer, 4 June 1962.
John Joseph Bittner, 56, geneticist whose researches in cancer were far-reaching, 14 December 1961.
Percy William Bridgman, 78, mathematician and physicist, 20 August 1961.
Dirk Brouwer, 63, Dutch-American astronomer and geophysicist, 31 January 1966.
Rachel L. Carson, 56, marine biologist and author of The Silent Spring (1962), which was instrumental in beginning the environmental movement in the United States, 14 April 1964.
William Weber Coblentz, 88, physicist, 15 September 1962.
Arthur Holly Compton, 69, physicist, winner of the 1927 Nobel Prize in physics for his work in quantum physics, 15 March 1962.
Peter Joseph Debye, 82, Dutch-American physical chemist, winner of the 1936 Nobel Prize in chemistry, 2 November 1966.
Lee DeForest, 87, inventor of one of the earliest processes for sound motion pictures, 30 June 1961.
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Irving Adler, The Elementary Mathematics of the Atom (New York: Day, 1965);
Adler, Thinking Machines (New York: Day, 1961);
Isaac Asimov, Intelligent Mans Guide to Science, 2 volumes (New York: Basic, 1960);
Asimov, Life and Energy (Garden City, N.Y.: Doubleday, 1962);
Charlotte Auerbach, The Science of Genetics (New York: Harper, 1961);
Marston Bates, The Forest and the Sea: A Look at the Economy of Nature and the Ecology of Man (New York: Random House, 1960);
George Beadle and Muriel Beadle, The Language of Life (Garden City, N.Y.: Doubleday, 1966);
Lincoln Bloomfield, ed., Outer Space (Englewood Cliffs, N.J.: Prentice-Hall, 1962);
Henry A. Boorse and Lloyd Motz, eds., The World of the Atom, 2 volumes (New York: Basic, 1966);
Hal Borland, ed., Our Natural World (Garden City, N.Y.: Doubleday, 1965);
R. L. F. Boyd, Space Research by Rocket and Satellite (New York: Harper, 1960);
J. Bronowsky, Insight (New York: Harper & Row, 1965);
Martin Caidin, The Astronauts: The Story of Project Mercury, America's Man-in-Space Program (New York: Dutton,...
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Important Events in Science and Technology, 1960–1969
- The first American use of geothermal power begins near San Francisco, employing steam under high pressure to produce electricity.
- The meter is redefined according to a wavelength in the spectrum of the gas krypton.
- On January 2, after studying a meteorite that had fallen in North Dakota in 1919, Dr. John H. Reynolds of the University of California estimates the age of the solar system to be 4.95 billion years.
- On January 12, General Electric introduces a thermoplastic tape capable of recording video and audio signals simultaneously.
- On January 23, the bathyscaphe Trieste plunges to the deepest part of Pacific Ocean, almost seven miles deep.
- In February, the U.S. Navy launches the USS George Washington, which carries sixteen Polaris missiles. The first nuclear submarine to carry nuclear warheads, it is able to attack anywhere at any time from an undetected location.
- In April, physicist Luis Alvarez identifies short-lived particles smaller than the subatomic protons, neutrons, and electrons as "resonances." The resonance might be a particle or several particles associated with each other.
- On April 1, the National Aeronautics and Space Administration (NASA) launches Tiros 1, the first weather satellite....
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