History of Astronomy

Aristarchus of Samos

230

230 BC
heliocentric theory- has the Sun in the center
calculated the diameter of the Sun as about seven times the diameter of the Earth
estimated the Sun’s volume as about 300 times the volume of the Earth www.varchive.org/ce/orbit/arisam.htm
http://www.russellcottrell.com/greek/aristarchus.asp
http://www.varchive.org/ce/orbit/arisam.htm

Aristotle

322

322 BC
Believed the world is round
Believes that the stars are much larger the earth
three kinds of motion: rectilinear, circular and mixed http://en.wikipedia.org/wiki/Aristotle
http://perseus.mpiwg-berlin.mpg.de/GreekScience/Students/Tom/AristotleAstro.html

Pythagoras

475

-believed that the planets were attached to crystalline spheres, one for each planet, which produced the Music of the Spheres
-these spheres were centered on the Earth, which was itself in motion
-recognized that the "morning star" and "evening star" are both the planet Venus http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Pythagoras.html
http://www.cass.ucsd.edu/public/tutorial/History.html

Ancient Greek

525

• http://en.wikipedia.org/wiki/Greek_astronomy
• Seeking a rational, physical explanation for celestial phenomena
• Most of the constellations of the northern hemisphere derive are taken from Greek astronomy, as are the names of many stars and planets

Nicolas Copernicus

Jan 1, 1543

-founder of modern astronomy
-wrote the De Revolutionibus which asserted that the earth rotated on its axis once daily and traveled around the sun once yearly http://www.blupete.com/Literature/Biographies/Science/Copernicus.htm
http://en.wikipedia.org/wiki/Nicolaus_Copernicus

Tycho Brahe

Oct 24, 1601

-devisied the most precise instruments available before the invention of the telescope for observing the heavens
-determine more precisely than had been possible the detailed motions of the planets
-compiled extensive data on the planet Mars http://galileoandeinstein.physics.virginia.edu/1995/lectures/tychob.html
http://csep10.phys.utk.edu/astr161/lect/history/brahe.html

Johannes Kepler

Jan 1, 1630

-First to correctly explain planetary motion= planets move in ellipses with the Sun at one focus
-First to explain the principles of how a telescope works
-First to explain that the tides are caused by the Moon
-First to suggest that the Sun rotates about its axis in Astronomia Nova
-He coined the word "satellite" http://kepler.nasa.gov/Mission/JohannesKepler/

Galileo Galilei

Jan 8, 1642

-significantly improved the telescope
-discovered three of Jupiter's moons
-one of the first to observe sunspots
-first to report that the moon had craters and mountains http://schools-wikipedia.org/wp/g/Galileo_Galilei.htm

Isaac Newton

Jan 1, 1727

-defined orbital motion
-studied gravity and its effects on objects such as planets and moons
-studied the tides and how gravity effects them http://www.newton.ac.uk/newtlife.html

E. Margaret Burbidge

Aug 12, 1919

-studied the spectra of galaxies, nuclear reactions at the center of stars, and conducted spectroscopic surveys of quasars
-developed a better explanation of how elements are formed by nuclear reactions inside stars
-was at the forefront of developing instrumentation for the Hubble Space Telescope
-signed forms in her husband's name to use the telescope, pretending to be his assistant, becuase women were not allowed
http://www.nndb.com/people/692/000168188/

Henrietta Swan Leavitt

Dec 21, 1921

-set up a standard for measuring a star's magnitude
-determined a way to determine distances of stars from a mere one hundred light years to ten million light years away http://www.womanastronomer.com/hleavitt.htm

George Hale

Feb 21, 1938

-invented the word astrophysics
-founded the Mt. Wilson Observatory
-mainly interested in the sun http://mwoa.org/hale.html

Annie Jump Cannon

Apr 13, 1941

Listed nearly 400,000 stars in Draper catalogs
Her "eye" for stellar spectra was phenomenal
She received many "firsts" suh as first recipient of an honorary doctorate from Oxford,and first woman elected an officer of the American Astronomical Society http://www.sdsc.edu/ScienceWomen/cannon.html

Edwin Hubble

Sep 28, 1953

-discovered that there are more then just our galaxy
-hubble's law- the velocity at which various galaxies are receding from the Earth is proportional to their distance from us http://www.absoluteastronomy.com/topics/Edwin_Hubble

Albert Einstein

Jan 1, 1955

special theory of relativity- When moving at high speeds, all of these things get compressed; only the speed of light remains the same; e=mc^2
a solar eclipse occurred in 1919 and astronomers made the observations that proved the general theory of relativity
made many controbution to physics http://www.pbs.org/wgbh/aso/databank/entries/bpeins.html

Gerald Kuiper

Dec 23, 1973

-father of modern planetary science
-developed new techniques of looking at the sky
-discovered a moon of Neptune and Uranus
-suggested that there was a belt of comet-like debris at the edge of our solar system http://www.windows2universe.org/people/today/kuiper.html

Bengt Georg Daniel Stromgren

Jan 1, 1987

-work on ionized gas clouds – H II regions around hot stars
-found relations between the gas density, the luminosity of the star, and the size of the Strömgren sphere of ionized hydrogen around it
problems of chemical composition of stellar structure and stellar interiors (1930–1940)
the physics of interstellar gas (1938–1953)
photoelectric photometry of stellar spectra (from 1948) http://www.daviddarling.info/encyclopedia/S/Stromgren.html
http://www.encyclopedia.com/topic/Bengt_Georg_Daniel_St

Subrahmanyan Chandrasekhar

Aug 21, 1995

-recoginzed for his work in stellar evoultion
-first to theorize that a collapsing massive star would become an object so dense that not even light could escape it
-contributed important theorems on the stability of cosmic masses in the presence of gravitation, rotation, and magnetic fields http://nobelprize.org/nobel_prizes/physics/laureates/1983/chandrasekhar-autobio.html

Eugene Shoemaker

Jan 1, 1997

-worked on the creation of a geological map of the moon
-studied craters
-extended his geological knowledge of the formation and spread of terrestrial and lunar impact craters to the study of the astronomical objects that formed them http://www2.jpl.nasa.gov/sl9/news81.html
http://en.wikipedia.org/wiki/Eugene_Merle_Shoemaker

Sir Fred Hoyle

Aug 20, 2001

-coined the phrase 'the big bang theroy"
-disagreed with singualrity
-agreed that the world was expanding
-became agnostic because he could not believe we were made by accident http://hoylehistory.com/famous-hoyles/fred-hoyle/

Grote Reber

Dec 20, 2002

-self taught in astronomy
-made the first radio telescope
-first to study throughly the radio waves across the sky http://www.nndb.com/people/090/000172571/
http://en.wikipedia.org/wiki/Grote_Reber

James Van Allen

Feb 3, 2006

-discovered that space is radioactive
-helped develop missles and other devices to test the upper atmosphere http://history.nasa.gov/sputnik/vanallen.html

Hipparchus

Feb 3, 2020

120BC
-measured the distance from the Earth to the Moon during a solar eclipse that was a total eclipse
-completed a star catalog with aproximently 850 stars
studied the motion of the moon http://www-history.mcs.st-andrews.ac.uk/Biographies/Hipparchus.html

Eratosthenes

Mar 2, 2022

-determined the circumfrence of the earth within 100 miles of the actual distance
-192 BC http://geography.about.com/od/historyofgeography/a/eratosthenes.htm
http://en.wikipedia.org/wiki/Eratosthenes