Download Ancient civilizations believed that Earth was at the center of the

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Lab starts this week—NS 017
Bring lab manual to lab
Do Prelab 1 before you go!
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Ancient civilizations believed that Earth was
at the center of the universe—GEOCENTRIC
MODEL
Age of Reason beginning to recognize Sun is
center of Solar System—HELIOCENTRIC MODEL
Age of Technology exploring wide reaches of
the universe
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5th century B.C.
Moon is a sphere lighted
by Sun
•http://www-history.mcs.st-andrews.ac.uk/Biographies/Anaxagoras.html
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4th century BC
Earth is a sphere
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3rd century BC
Mathemetician
Placed Sun at center
with Earth orbiting it
•http://www.hao.ucar.edu/public/education/sp/images/aristotle.html
•http://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_the_Earth
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2nd century AD
Copies of works
survive to this
day
T
Translated
l t d tto
Arabic early, to
Latin in 13th
century
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Mars usually moves across sky west to east
Occasionally appears to move east to west
Occurs when Earth is ‘passing’ Mars
•http://archive.ncsa.uiuc.edu/SDG/Experimental/vatican.exhibit/exhibit/full-images/d-mathematics/math21.gif
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Earth would fly apart if it rotated on an axis
Moon would be left behind if Earth orbited Sun
Since God created Earth and Sun and all the
heavenly bodies, Earth is the center of the
universe
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Thought Earth was the unmoving center
Earth rotates on an
axis, instead of
everything orbiting
Earth
Earth orbits Sun like
the planets, so it a
planet too
“On the Revolution
of the Heavenly
Spheres”, 1543
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http://www.hao.ucar.edu/public/education/sp/images/copernicus.html
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Translated into Latin in 13th century
Influenced intellectual thought for centuries
Detailed
observations of
movement of planets
http://www.hao.ucar.edu/public/education/sp/images/tycho.html
His careful observations
and records are his most
important legacy
http://www.hao.ucar.edu/public/education/sp/images/tycho.3.html
http://www.hao.ucar.edu/public/education/sp/images/tycho.1.html
http://www.hao.ucar.edu/public/education/sp/images/tycho.2.html
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Discounted
Copernicus
model because
he could not
discern stellar
parallax
It does exist, he
didn’t have
tools to see it
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Tycho’s assistant and
successor
Used Tycho’s data to
determine planetary
orbits are elliptical
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Orbit of
planet is
ellipse
Sun at one
Focus
http://en.wikipedia.org/wiki/Image:Johannes_Kepler.jpg
http://www.hao.ucar.edu/public/education/sp/images/tycho.4.html
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p2=d3
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p=Period (time to orbit Sun) in Earth years
d=Distance in Astronomical Units:
1 A.U.=distance from Earth to Sun
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Equal areas in equal time intervals accounts
for the uneven speeds
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Strong supporter of
Copernican model of
planetary movement
Built
u lt 30x
30 telescopes
(from descriptions of the
devices) and looked at
planets and Moon
starting in 1609
http://en.wikipedia.org/wiki/Galileo_Galilei#Technology
Telescope used to see that
another body in solar system
is a center of orbital
movement
These moons are not left
behind, and Earth’s Moon is
not either
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Explained the orbital
motion of planets as
the interaction of
inertia and gravity
Invented the calculus
to simplify his
calculations of
motion
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When viewed by telescope, planets look like
discs, not points of light as stars do
Jupiter has moons
Venus has phases
Moon’s surface has texture
Sun rotates on an axis
Sun is at the center of the solar system
Published by Copernicus
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Supported by Galileo’s telescopic observations of
Jupiter and Venus
Kepler determined orbits are ellipses
Newton determined orbits created by
interaction of inertia and gravity
1851
Supports that Earth does
rotate on its axis—Copernicus’
hypothesis
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