Download The Copernican Revolution What`s in the Center? Aristotle

The Copernican Revolution
The Sun-Centered Universe
To me, whether the Earth revolves around the Sun, or the other
way around, no question could have any less importance.
- Albert Camus
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What's in the Center?
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1)
2)
Two Questions
Does the Earth rotate or the Celestial
Sphere?
Does the Earth go around the Sun or the
Sun around the Earth?
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Aristotle
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The Celestial Sphere
rotates.
The Sun moves
around the Earth.
The Earth is
completely stationary.
Aristotle
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Aristarchos
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1)
2)
According to Archimedes, taught:
The Earth rotates on its axis.
The Earth moves around the Sun.
Archimedes
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The Stellar Parallax
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Ptolemy
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The Great Astronomer - 150 AD
the Almagest—astronomy textbook
Found no stellar parallax.
Argued against Aristarchos.
Developed theory of motion of the
planets.
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Stellar Parallax
Q. The failure to observe the stellar
parallax proved that…
1) The Sun went around the Earth.
2) The Earth went around the Sun.
3) Somebody needed to get busy
and invent the telescope.
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The Problem of
Planetary Motion
1)
2)
Why do the inferior planets never reach
opposition?
Why do the superior planets go backward
(retrograde) at opposition?
Retrograde motion of Mars
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The Ptolemaic Theory
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The Earth is the center.
The Sun and all the
planets orbit the Earth.
The planets move in
epicycles.
Earth
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Unanswered Questions
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Why do the superior planets go into
retrograde only at opposition?
Why do the inferior planets go into
retrograde only at inferior conjunction?
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The Dark Ages
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Astronomy in 1500
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Earth-centered model
unquestioned.
Alphonsine Tables (1252) used to
calculate planet motions.
Planets often far from predicted
positions.
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Nicolaus Copernicus
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Born Torun, Poland 1473.
Educated Cracow and Italy
Canon at Cathedral of
Frauenburg, Ermland, Prussia
Published On the Revolution
of the Spheres in 1543
Died 1543.
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The Sun-centered System
Q. What is
not going
around the
Sun?
Sun
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Europe in 1500
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Aristotle was considered the authority in philosophy.
Experimentation was unrespectable.
Astronomy was the only respectable natural science.
Earth-centered Universe was tied to Christian
theology.
Earth the place of suffering;
heaven the place of perfection.
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Winds of change
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1450 – printing press
1492 - Columbus
1520 – Martin Luther
1543 – Copernicus publishes the
Sun-centered theory
Martin Luther
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Arguments for the
Copernican Theory
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Puts the largest body (Sun) in the
center.
Treats all the planets alike.
Explains Venus & Mercury simply.
Explains retrograde motion of
Mars, Jupiter, and Saturn simply.
Predicted relative distances of the
planets from Sun.
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Occam’s Razor
When choosing between two competing theories,
choose the simpler one.
"Entia non sunt multiplicanda sine necessitate".
- William of Occam
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Arguments Against the
Copernican Theory
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It contradicted Scripture(?)
Lack of effects of Earth’s rotation.
Earth would fall to center due to
gravity.
Failure to observe the stellar
parallax.
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The Controversy Begins
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Reinhold: Prutenic Tables
(1551)
Thomas Digges (1576)
William Gilbert (1600)
Giordano Bruno (1600)
Bruno
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The Execution of Bruno
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