The Astronomical Society of the red Sea of Arabia, ASRA is pleased to publish, for the first time, some parts from an article written in the respectful Astronomy Magazine, the world's best seller astronomy magazine.
The title of the article is : 100 years of astronomical discoveries.
The complete article was published in the September 2016 issue of the magazine.
CONTINUATION OF THE ARTICLE.
THE FOURTH DECADE THE 1930s.
1930
Astronaut Buzz Aldrin, the second man to walk on the moon, is born January 20 in Montclair, New Jersey, USA.
German optician Bernhard Schmidt invents the Schmidt telescope, a nearly distortion - free telescope that allows astronomers to take wide - field photos with relatively short exposures.
Astronaut Neil Armstrong, the first man to walk on the moon, is born August 5 in Wapakoneta, Ohio, USA.
Swiss- American astronomer Robert Trumpler discovers that interstellar dust permeates the Milky Way Galaxy after finding that stars in distance open clusters appear dimmer than expected.
The institute for advanced study in Princeton, New Jersey is founded. It would soon attract such notable figures as Albert Einstein, Kurt Godel, Wolfgang Pauli, John von Neumann, and Hermann weyl.
(Clyde Tombaugh discovers Pluto.)
Astronomically speaking, the 1930s get of to a great start. On February 18, 24 years old Clyde Tombaugh steps into Vesto Slipher's office at Lowell Observatory to tell the director that he has found an object fitting the bill for a planet beyond Neptune. Slipher had hired Tombaugh, a Kansas farmer boy, to do the grunt work of a photographic survey to look for a suspected "plane X".
By early April 1929, Tombaugh was photographing through the new 13 inch astrograph with its custom made objective. Using large plates, he began taking images of the sky along the zodiac- the region where all the planets reside. He photographed each area a few days apart and then examined the two plates using a blink comparator. This device allowed Tombaugh to flip rapidly between the two plates and find anything that moved against the distant background stars. And there were lots of moving objects. After thousands of hours of flipping, Tombaugh spots a 15th magnitude candidate not far from the guide star Wasat (Delta Geminorum). He is convinced it is a new planet, and soon everyone else is, too.
Pluto presents problems from the beginning, however. This is not the Planet X astronomers had expected- it is too small, rocky, and its orbit far more elliptical than any of the other planets. Yet it quickly takes its place as the solar system's ninth planet, where it will remain for 76 years, until astronomers relegate it to dwarf planet status in 2006.
1931
German physicist Ernst Ruska and German electrical engineer Max Knoll invent the electron microscope, which delivers far better resolutions than a traditional light microscope.
American chemist Harold Urey discovers deuterium, a heavy isotope of hydrogen that contains one proton and one neutron in its nucleus.
Albert Einstein begins a three years stint working at the California Institute of Technology in Pasadena, USA.
(French Astronomer Bernard Lyot invents the chronograph.)
For centuries, astronomers chased solar eclipses in an effort to unlock the secrets of the Sun. These efforts often proved expensive and dangerous- a few astronomers even paid with their lives. As all astronomers know, to see one of these rare events, an observer has to be within a narrow band on earth's surface at precisely the right time. If the sky is clear, the reward is a spectacular view of sun's outer atmosphere, the corona.
In 1931, French astronomer Bernard Lyot invents a device that allows astronomers to view the diaphanous gas surrounding the sun at any time the sun is visible. Lyot has his work cut out for him. He designs an "occulting disk" which fits in line with the optics of a telescope, to block the bright solar surface. Unfortunately, a lot of stray light still enters the telescope's optical path. He solves this problem by using a series of lenses with stops to further reduce the light. Fittingly called Lyot stops, all chronographs now use them.
Lyot invention has far reaching consequences. Chronographs adorn telescopes in space that constantly monitor the sun's outer atmosphere and astronomers use these devices to block the light of other stars to hunt for and study exoplanets and circumstellar disks.
1932
English physicist James Chadwick discovers the neutron, a neutral particle with the mass close to that of a proton that keep atomic nuclei stable.
American physicist Carl Anderson discovers the positron, a particle with the same mass as an electron but the opposite charge, it is the first evidence for antimatter.
Estonian astronomer Ernst Opik proposes that long period comets originate in a distant region of the solar system now known as the Oort Cloud, named after Jan Oort, who will independently suggest the idea in 1950.
American physicist Roy Kennedy and American psychologists Edward Thorndike conduct the first Kennedy - Thoorndike experiment, which verifies time dilation and supports Einstein's special theory of relativity.
American astronomers Walter Adams and Theodore Dunham discovers copious amounts of carbon dioxide in the atmosphere of Venus.
German astronomer Rupert Wildt discovers methane in Jupiter's atmosphere.
1933
Swiss astronomer Fritz Zwicky proposed dark matter as the gravitational glue that keeps galaxies in the vast Coma Cluster of Galaxies bound together.
(The birth of radio astronomy.)
Shortwave radio communications have become vital by the 1930s. Such transmissions can carry long distances because these radio waves bounce off the ionosphere and thus can bend around Earth's curvature. Unfortunately, interference constantly disrupts communications. Scientists at Bell laboratory are asked if they can identify the problem.
Karl Jansky is put to the task and completes it with what proves to be cosmic results. His first job is to determine where the static disturbances are originating. To do this, Jansky builds a directional antenna about 100 feet (30 meters) long and 20 feet (6 meters) tall. The whole thing is mounted on a large turntable so it can be rotated. Jansky began his observations in 1930 and spent the next year recording and analyzing the static. He identified both nearby and distant thunderstorms as causes of interference. But a third mystery source seemed to be emanating from the sun. With time, however, the static source appeared to move away from the sun.
Jansky soon realizes that the static followed a sidereal day of 23 hours and 56 minutes, meaning it had to be located far beyond the solar system. After he correlated his observations with astronomical charts, he pinpoints the mystery signal as originating from the constellation Sagittarius, and publishes his results in 1933. By 1935, he would conclude that the signals were coming from the center of the Milky Way Galaxy.
1934
German astronomer Walter Baade and Swiss astronomer Fritz Zwicky propose that the gravitational collapse of a massive star could trigger a huge explosion and leave behind a neutron star, Zwicky coins the term supernova for the blast.
Soviet astronaut Yori Gagarin the firs human to orbit earth, is born March 9 in Klushino, outside Moscow.
Astronomer and science popularizer Carl Sagan is born November 9, in Brooklyn New York, USA.
1935
American engineer Arthur Hardy patents the spectrophotometer, a device used to measure the intensity of light as a function of wavelength.
British scientists Robert Watson watt and Arnold Wilkins conduct the first radar experiments, which ultimately would be used to detect German aircraft during the battle of Britain in World War Two.
(Rocket Man takes off.)
American engineer Robert Goddard began working on rocket design in 1914, when he received two U.S. patents. Later, while teaching at Clarke University in Worcester, Massachusetts, he terrified the locals with his rocket experiments, including the March 16, 1926, launch of the first liquid fuel rocket. With the help of Charles Lindbergh - (who was an American aviator who in 1927, at age 25, makes his first nonstop flight ever across the Atlantic Ocean from Long Island, New York, to Paris) - and funding from the Guggenheim family, Goddard relocated to Roswell, New Mexico, in 1930. For the next few years, the developed new and better propulsion and guidance systems that enabled his rockets to fly with more stability.
Goddard achieves some of his greatest successes in 1935. On March 8, he conducts a test flight in which the rocket roared in a powerful ascent and reaches nearly the speed of sound. Later that same month, using liquid fuel and gyroscope stabilization, Goddard launches a rocket that rises nearly a mile (1.6 kilometers) and then turns on to a horizontal trajectory for another 2.5 miles (4 kilometers). His guidance system will become the crucial factor in developing usable rockets.
Although Goddard had been trying to Interest the American government in his research since the 1920s, he had no luck. Even as the threat of World War Two grew in Europe, his work received very little attention. Others, however, are following his work very closely. The German military is keen on developing rockets for their own war efforts. After the war, German rocket builder Wernher Von Braun, the engineer who built the V1 and V2 rockets, would state that Goddard had been ahead of them all. Still, it would be years before America realizes the extent to which it had neglected Goddard's efforts.
1936
The Carnegie Institution of Washington publishes the Boss General Catalogue, a list of 33,342 stars compiled by American astronomer Benjamin Boss that contains their positions, magnitudes, proper motion, and spectral types.
(A giant mirror goes for a train ride.)
The mirror that would become the glass giant of Palomar telescope and open a universe of wonders leaves the Corning Glass Factory in Corning, New York, on March 26 for a 16 days trip across America. The idea for the behemoth telescope atop Palomar Mountain in Southern California is the brainchild of George Ellery Hale, the former director of Wisconsin's Yerkes Observatory and the man behind the 60 and 100 inch (1.5 and 2.5 meters) telescope on Mount Wilson.
Although Hale received 6 million dollars for the project from the Rockefeller foundation in 1928, he went back to the American people at the height of the Great Depression to raise more money. Children taped dimes to postcards and mailed them to Hale in support of his endeavor. As the mirror makes its way through the American heartland, people line the train route to watch history pass through their towns. Locals have to raise a number of bridges to allow the upright mirror to pass. But not everyone views the transport favorably, however, and few take potshots at the massive crate. Thankfully, no damage is done.
The mirror blank arrives at California Institute of Technology's optical shop in Pasadena without incident. It would require workers more than a decade to grind and figure the 200 inch (5.1 meters) mirror to the correct parabolic shape, in part because of the delays caused by World War Two. Astronomer Edwin Hubble finally takes the first photo of the night sky with this marvel January 26, 1949, nearly 11 years after Hale dies.
1938
On June 24, a 450 ton meteor explodes some 19 kilometers above Chicora, Pennsylvania, USA, creating a huge fireball.
Albert Einstein and Polish physicist Leopold Infeld publish "the evolution of physics", a book intended for the general public that outlines the development of ideas in physics.
German American physicist Hans Bethe demonstrates that stars generate energy through the nuclear fusion of hydrogen into helium.
(The birth of nuclear fission.)
It is surprising how many people think wrongly that Albert Einstein invented the atomic bomb. But the story of the discoveries that led to the atomic bomb begins at Christmas in 1938. Lise Meitner had been the head of physics department at the Kaiser Wilhelm Institute for Chemistry in Berlin, Germany. Being of Jewish ancestry she eventually flees Nazi Germany for Sweden. Alone and miserable, she welcomes a visit from her nephew, physicist Otto Frisch, over Christmas in 1938.
Immediately they begin to talk about news from a colleague and former scientific collaborator, Otto Hahn, and his work in nuclear physics back in Berlin. Hahn has been bombarding uranium atoms with the newly discovered neutrons with some very interesting results.
Meitner and Frisch soon work out why no natural elements beyond uranium could exist (because all of these heavy elements are unstable and decay radioactively into other lighter elements). They also applied Einstein's famous equation, "E = mc2." , and come to fully realize the true nature of the energy that would be released by fission.
Meitner is appalled at the idea of an atomic bomb, and refuse to do any work related to the subject. Despite her fundamental contributions, she would be passed over for Nobel Prize in chemistry for her work in fission, which goes solely to Otto Hahn in 1944.
(The War of the Worlds.)
With a script based solely on the H. G. Wells novel "The War of the Worlds", a young George Orson Welles the American actor plans to give the American people a bit of a scare with the 1938 Halloween broadcast of the Mercury Theater on the air. When listeners turn into the Colombia Broadcasting System, they are expecting a typical Sunday night radio drama. Three minutes into the program, they hear : "ladies and gentlemen, we interrupt our program of dance music to bring you a special bulletin". If they had missed Welles's introduction, what followed sounds all too real.
According to some accounts, widespread panic develops as people sit glued to their radios, listening to the unfolding drama of an apparent invasion from Mars. Eventually New York policemen appear at the radio studio and try to get in to stop the broadcast. One report of mobs in the streets of at least one Midwestern town comes in.
How can the public have been so easily fooled ? Well, it is 1938, and astronomers are still debating the possibility of life on Mars. And war in Europe seems a real possibility, and the country is still in economic turmoil. Welles takes a bit of science and the Behavioural Psychology fact which states that "incompetent people are so ignorant to know it", and the fears of people who have been through so much, and create a believable falsehood.
1939
American physicist Robert Oppenheimer the father of the atomic bomb, and the Canadian physicist George Volkoff calculate the structure and properties of neutron stars.
American astronomer john Duncan publishes his measurements showing the rate of the Crab Nebula's expansion during the previous 29 years. He estimates that it formed in an outburst (supernova explosion) around the year 1172 (118 years later than the now accepted date which is 1054).
(Einstein Writes a Letter.)
So much of physics and astronomy in the 1930s ties together that it is often difficult to separate the two, and perhaps we shouldn't try. In 1938, lies Meitner and Otto Frisch found how massive amounts of energy could be released through nuclear fission reactions. Their work led to what would amount to the original nuclear arms race. Meitner and many other physicist refused to be drawn into efforts to creat an atomic bomb. The most famous of these reluctant scientists was Albert Einstein.
Einstein an avid pacifist. The closest he ever came to military service was when he became a Swiss citizen. As with all able bodied Swiss men, he was issued a rifle, which gathered dust above his fireplace. In 1939, several prominent physicist approach him with the idea of writing a letter to president Franklin D. Roosevelt to advance him with the idea of atomic research with a goal of making an atomic bomb. Although initially reluctant to become involved, Einstein eventually signs a letter written by fellow German- Hungarian physicist Leo Szilard that encourages president Franklin D. Roosevelt to act before Germany can obtain such a weapon. The power of the atom is about to be released upon humankind.
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