Famous Astronomers

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Famous Astronomers
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•   Famous Astronomer Websitehttp//www.windows.
  ucar.edu/tour/link/people/ancient_epoch.htmlcdp
  /windows3.htmlfrp/windows3.html
•  

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The Ancients Before 700 BCE
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Aristotle

• Earth center of the Universe
• Composed of four elements Earth, Water, Air and
  Fire
• Believed the sun, moon and stars were perfect and
  made of aether, the perfect air of the heavens
  that was breathed by the gods.
• Also believed that since the heavenly bodies were
  perfect they must travel in a circular motion.

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Democritus

• Developed the theory of the atom which in Greek
  means indivisible.
• He believed everything in the Universe was made
  of atoms.

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Eratosthenes

• Made the first good measurement of the
  circumference of the Earth.
• How did he do it?
• http//astrosun2.astro.cornell.edu/academics/cours
  es//astro201/eratosthenes.htm
• We are not quite sure how accurate he was because
  he used a unit called a stadia.
• At worst he was within 16 accuracy and many
  believe he was within 1 accuracy.

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Hipparchus

• 1st accurate star map
• He may have been the first to tell time using the
  stars at night.

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Hypatia

• Teacher of mathematics, philosophy and astronomy.
• 1st woman known to make a substantial
  contribution to mathematics.
• Killed for teaching pagan beliefs.

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Ptolemy

• Geocentric Universe the Earth is the center of
  the universe and all the other celestial bodies
  circle it.
• We know from observation that the universe moves.
• We know it appears to move in a circular motion.
• A circle must have a center and simple
  observation shows everything moving around the
  Earth.
• Therefore the Earth is the center of the
  universe!
• http//www.wsu.edu/7Edee/ENLIGHT/SCIREV.HTM

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Middle Ages 700 -1400 CE
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Abd al-Rahman al-Sufi

• After the fall of the Roman Empire and the
  destruction of the library of Alexandria, it was
  the Persian Empire that kept the knowledge of the
  Greeks alive and added to it with their own.
• One of the great Arabian astronomers was Abd
  al-Rahman al-Sufi. In 964 he predicted the
  existence of the Andromeda Galaxy.

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Renaissance 1400-1650 CE
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Nicolas Copernicus

• Polish
• A true Renaissance Man
• Canonized by the church
• Practiced both medicine and law
• On the Revolutions of the Heavenly Spheres, 1543
  Heliocentric view of the universe.
• Wrote on his death bed.

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Nicolas Copernicus

• Copernicus proposed that a rotating Earth
  revolving with the other planets about a
  stationary central Sun could account in a simpler
  way for the same observed phenomena of
• The daily rotation of the heavens
• The annual movement of the Sun through the
  ecliptic
• The periodic retrograde motion of the planets.

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Tycho Brahe

• Danish
• Beginning of a modern approach to astronomy that
  led to Kepler and Galileo.
• Designed his own tools for astronomy.
• Think of him as the Thomas Edison of astronomy.
• 1st observatory
• No telescopes
• Challenged geocentric view

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Galileo Galilei

• Italian
• 1st telescope
• Pendulum
• Speed of Gravity
• Spent the last years of his life on house arrest
  for challenging the inquisition.
• http//www.teachersdomain.org/resources/ess05/sci/
  ess/eiu/galileosys/index.html

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Johan Kepler

• I. The orbits of the planets are ellipses, with
  the Sun at one focus of the ellipse.
• II. The line joining the planet to the Sun sweeps
  out equal areas in equal times as the planet
  travels around the ellipse
• III. The ratio of the squares of the
  revolutionary periods for two planets is equal to
  the ratio of the cubes of their semimajor axes

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Age of Enlightenment 1650-1850 CE
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Edmond Halley

• Comet every 76 years
• After studying comets, he noticed that the path
  of the comets of 1456, 1531, and 1607 were
  surprisingly similar.
• He surmised that these three sightings were
  different apparitions of a single comet, which
  he predicted would return again around 1758.
• He died before his prediction was tested, but the
  comet indeed returned and has been known as
  Halley's Comet ever since.

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Simon Marius

• Named Galilean moons
• Claimed to have views Jupiters moons before
  Galileo

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William Herschel

• Known for the only discoveries of new moons and
  planets in the 18th century.
• Discovered Uranus and its moons Oberon, Titania
• Saturns moons Enceledas and Mimas

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Christiaan Huygens

• Improved telescopes
• First identified Saturns rings and one of
  Saturns moons.

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Maria Mitchell

• The first female professor of astronomy in the
  United States.
• In 1848, she was the first woman appointed to the
  Academy of Arts and Sciences.
• In 1853, she received the first advanced degree
  given to a woman from Indiana Hanover College.
• After Mitchell's death, a crater on the moon was
  named after her.

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James Maxwell

• Scottish
• His work and the earlier work of Michael Faraday
  on electricity and magnetism led to quantum
  physics and theory of relativity

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Sir Isaac Newton

• I. Every object in a state of uniform motion
  tends to remain in that state of motion unless an
  external force is applied to it.
• II. The relationship between an object's mass m,
  its acceleration a, and the applied force F is F
  ma. Acceleration and force are vectors (as
  indicated by their symbols being displayed in
  slant bold font) in this law the direction of
  the force vector is the same as the direction of
  the acceleration vector.
• III. For every action there is an equal and
  opposite reaction.

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Giovanni Schiaparelli

• Viewed a system of channels on Mars
• Due to a mistranslation as canals many thought he
  saw water canals made by intelligent creatures
  leading to a frenzy of information claiming life
  on Mars.

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Modern Era 1850-1950 CE
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Albert Einstein

• German
• Theory of Relativity Emc2
• Special Theory of Relativity explores time and
  space as it approaches the speed of light.

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Robert Goddard

• American Physics Professor who became the Father
  of modern rocketry.
• Published a paper called "A Method of Reaching
  Extreme Altitudes," where he argued it was
  possible to send a rocket to the moon.
• The Times laughed at him claiming space travel
  was impossible because there is no atmosphere to
  push against.

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George Hale

• American Astronomer
• Spectrohelioscope a combination of a telescope
  and a spectroscope.
• It is used to measure the chemicals that make up
  the stars.
• He developed the field of astrophysics.

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Werner Heisenberg

• Uncertainty Principle
• Stated that the act of observing changes the
  reality being observed.
• This seems obvious but he went on to
  mathematically prove this is true!

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Edwin Hubble

• American
• Modern astronomy began with Edwin Hubble in the
  1920s who is credited with the Big Bang theory.
• Hubble observed that the universe is always
  expanding.

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Max Planck

• German
• Father of quantum mechanics
• He showed that classical physics could not
  explain the actions of subatomic particles.
• It was his discoveries that inspired Einsteins
  theories on relativity.

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Ernest Rutherford

• New Zealand
• He is considered the father of nuclear physics.
• Rutherford believed that an atom is like a small
  planetary system, with the protons and neutrons
  in the center (like the sun), circled by
  electrons (like planets).
• Rutherford also studied radioactivity.
• He named and identified alpha and beta particles.

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Todays Scientists 1950-Now
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Werner von Braun

• German
• Dreamed of space travel all his life.
• Once arrested by the Gestapo for his stories
  about traveling to the moon.
• Early pioneer of the American space program.

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Stephen Hawking

• British
• Crippled by Lou Gherigs disease. He is
  completely dependent on a wheelchair for movement
  and cannot speak without machines.
• He is the leading theoretical physicist in the
  field of general relativity and the theory of
  black holes.

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Gerard Kuiper

• Predicted objects beyond Pluto
• His curiosity led to Pluto no longer being
  considered a planet.
• Interesting note is that Kuiper had it all wrong.
  
• He thought Pluto was much bigger and had a
  greater effect on solar system then it actually
  does.

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Carl Sagan

• American
• Died in 1996 at the age of 62.
• Popularized science in books, television and
  movies by fascinating the public with his search
  for life on other planets.
• He had a major role in every space probe the
  United States sent to other planets.