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Lab starts this week—NS 017Bring lab manual to labBring lab manual to lab

Do Prelab 1 before you go!

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

5th century B.C. Moon is a sphere lighted

by Sun

•http://www-history.mcs.st-andrews.ac.uk/Biographies/Anaxagoras.html

4th century BC Earth is a sphere

•http://www.hao.ucar.edu/public/education/sp/images/aristotle.html

3rd century BC Mathemetician Placed Sun at center

with Earth orbiting itwith Earth orbiting it

•http://en.wikipedia.org/wiki/Eratosthenes#Measurement_of_the_Earth

2nd century AD Copies of works

survive to this dayT l t d t Translated to Arabic early, to Latin in 13th

century

•http://archive.ncsa.uiuc.edu/SDG/Experimental/vatican.exhibit/exhibit/full-images/d-mathematics/math21.gif

Mars usually moves across sky west to east Occasionally appears to move east to west Occurs when Earth is ‘passing’ Mars

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Thought Earth was the unmoving center

Translated into Latin in 13th century Influenced intellectual thought for centuries

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 heavenly bodies, Earth is the center of the universe

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

http://www.hao.ucar.edu/public/education/sp/images/copernicus.html

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

http://www.hao.ucar.edu/public/education/sp/images/tycho.4.html

Tycho’s assistant and successor

Used Tycho’s data to determine planetary determine planetary orbits are elliptical

http://en.wikipedia.org/wiki/Image:Johannes_Kepler.jpg

Orbit of planet is ellipse

Sun at one Focus

Equal areas in equal time intervals accounts for the uneven speeds

p2=d3

p=Period (time to orbit Sun) in Earth yearsd=Distance in Astronomical Units:

1 A.U.=distance from Earth to Sun

Strong supporter of Copernican model of planetary movement

Built 30x telescopes u lt 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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When viewed by telescope, planets look like discs, not points of light as stars do

Jupiter has moons Venus has phases Venus has phases Moon’s surface has texture Sun rotates on an axis

Explained the orbital motion of planets as the interaction of inertia and gravity

Invented the calculus to simplify his calculations of motion

Sun is at the center of the solar system Published by Copernicus

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