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Transcript of Harlow Shapley
by Shayna Hipson, Jenny Post, and Katie Stefanik
How has he affected the world we live in today?
Harlow Shapley was one of the most stimulating figures in twentieth century science.
Without Harlow Shapley, we may not have the identifications and calculations of stars that we have today because of his encouragement for the completion and extension of the Henry Draper Catalogue of stellar spectral classifications.
We also may not be searching for further life due to his writings about the Liquid Water Belt, which he defined as the region in a planetary system in which liquid water could exist at a planet’s surface. Where water exists, life exists.
Hubble may not have gone on to shape the modern view of the universe due to Shapleys fierce critiques.
Henry Draper Medal of the National Academy of Sciences (1926)
Prix Jules Janssen of the French Astronomical Society (1933)
Rumford Prize of the American Academy of Arts and Sciences (1933)
Gold Medal of the Royal Astronomical Society (1934)
Bruce Medal of the Astronomical Society of the Pacific (1939)
Franklin Medal (1945)
Henry Norris Russell Lectureship of the American Astronomical Society (1950)
Early Childhood-Beggining of life at University
Born in Missouri in 1885, he was one of two fraternal twins.
He dropped out of school with the equivalent of a fifth-grade education.
He worked as a crime reporter
He continued studies at home, but later returned to complete a six-year HS program in 1.5 years and graduated as class valedictorian.
His years attending University
In 1907, at the age of 22, he entered U Missouri with full intention to study journalism. However, upon arrival, he found there to be no program for journalism.
As he intimates in his autobiography, it was almost by accident that he selected astronomy as his special field of study.
One of his professors, Frederick H . Seares, became his mentor and provided him all the opportunities he needed.
At Princeton, he studied the cepheid variable stars, which were at that time generally suspected of being a type of binary star.
From discussions with Russell, it soon became clear that the binary star hypothesis was untenable; and the two developed a new theory to explain the variations in light, color, and radial velocity for the cepheid variables.
Timeline of Shapleys Life
Harlow Shapley received the A.B. degree from the Univer- sity of Missouri in 1910. He stayed on for an additional year, and in 1911 he received the degree of A.M.
Through his reading of the classics, he had become much interested in Horace. His first printed paper appeared in Popular Astronomy in 1909; entitled "Astronomy in Horace."
In 1911, Harlow attended Princeton, that had a small but distinguished astronomical faculty.
Henry Norris Russell, with whom Harlow later would collaborate, headed the Department and was a well-known astronomerof the day in the then- young field of astrophysics.
Together, the two made the theory for the analysis of light curves of eclipsing binaries: a theory that even today dominates analysis in this area.
Not much was published on the subject during the time that Shapley was still at Princeton, but shortly after arriving at Mount Wilson Observatory (1914), he completed a paper, "On the Nature and Cause of Cepheid Variation," in which he explained that cepheid variables are most likely pulsating single stars. In modified form, the pulsation theory still holds sway.
As he obtained a junior Astronomer position at Mount Wilson Observatory, he decided to go to Harvard College Observatory.
There, conversations with Solon Irvin Bailey led Shapley to undertake the study of globular star clusters, which became his principal concern at Mount Wilson.
Because he undertook the study of variable stars in globular clusters, he was led to the discovery of the center of our Milky Way system,
In the 1940s, Shapley helped found government funded scientific associations such as the National Science Foundation.
He is also responsible for the addition of the "S" in UNESCO (United Nations Educational, Scientific and Cultural Organization).
In 1953, he wrote the "Liquid Water Belt" which gave scientific credence to the ecosphere theory of Hubertus Strughold.
Harlow Shapley died on October 2, 1972, in Colorado.
Harlow Shapley's Observations
Prior theories of the Milky Way
In the 18th century, William Herschel made the first attempt to determine accurately the shape of our galaxy. He counted the number of stars visible in 683 lines of sight leading away from the Sun. If he saw few stars, he concluded that the edge of the Galaxy was very near in that direction. If he saw many stars, he concluded that the edge of the Galaxy was far away. The grand conclusion: the galaxy is shaped like an irregular "grindstone''. (The stones used to grind wheat in the 18th century)
A cross-section of our galaxy, as plotted by Herschel, is shown here. The Sun is slightly off-center to the left. (Ryden, Ohio Univ.)
Unfortunately, Herschel didn't know that dust obscures our view of distant stars. Contrary to Herschel's belief, the Sun is not close to the center of our galaxy.
Made a better attempt to determine the shape and size of our galaxy made in the early 20th century.
While studying globular clusters (dense clusters containing hundreds of thousands of stars, he noticed a couple of hundred globular clusters in a spherical swarm surrounding our galaxy.
If the Sun were at the center of our galaxy, we would see equal numbers of globular clusters in all directions. However, Shapley found that globular clusters all tend to lie on one side of the sky, in the direction of the constellation Sagittarius.
Therefore, Shapley concluded, the center of our galaxy lies in the direction of Sagittarius.
Shapley was also able to measure the distances to globular clusters. The clusters contained RR Lyrae variable stars. Every RR Lyrae variable star has a luminosity of about L = 80 Lsun. By measuring the apparent brightness b of each RR Lyrae, he could compute its distance from the relation L = 4 pi d2 b.
Shapley's plot of the distribution of globular clusters is shown above. The red X to the right is the center of our galaxy, as defined by the positions of the globular clusters. (Ryden)
Basic Facts of the Milky Way Galaxy
- Made up of dust, gas, stars and dark matter.
About 100,000-120,000 light years across in distance, containing roughly 100-400 billion stars, and potentially just as many planets.
- The sun is not at the center, our solar system lies about 30,000 light years from the center.
- Center is Sagittarius A, a bright radio source, that is likely to be a supermassive black hole.
-Red Dwarfs are the most common star.
- As our solar system is embedded within, however the Milky Way Galaxy is one of many galaxies in our universe.
Unfortunately, Shapley's distance measurements were too large (he underestimated the dimming power of dust). The best current estimate is that the Sun is 8000 parsecs (26,000 light years) away from the center of our galaxy.
Things named after him:
The crater Shapley on the Moon, Asteroid 1123, Shapleya Shapley Supercluster, and the Harlow Shapley Visiting Lectureships.
Shapley has been compared to Copernicus: Copernicus pointed out that the Earth is not at the center of the Solar System - it's just one of nine planets. Shapley pointed out that the Solar System is not at the center of our galaxy - it's just one of 200 billion stars.
Shapley was a renaissance man in regards to science. Essentially, he had many contributions to the science world.
He sobered society with the thought that we are once again not the center of everything. In fact, we are tiny specs in an infinite universe.