DOC PREVIEW
UT AST 350L - Lecture 8: Kepler I

This preview shows page 1-2-3-19-20-38-39-40 out of 40 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 40 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

The History and Philosophyof Astronomy (Lecture 8: Kepler I)Instructor: Volker BrommTA: Amanda BauerThe University of Texas at AustinAstronomy 350L (Spring 2005)Between Epochs: Renaissance – Baroque (1550-1650) El Greco (1541-1614)Lucas Cranach (1515-1586)• Crisis in Europe: Religious conflict (Catholic vs Protestant)Europe: Deeply divided into multiple confessionsReformation vsCounter Reformation • Reformation:- Bible in vernacular• Counter Reformation:- Council of Trent (1545-63)• Sola ScripturaCounter Reformation: The Jesuits • Intellectual avantgarde against Reformation- eventually: arch-enemies of Galileo (~1633)Ignatius of Loyola (1491-1556)War: England defeats Spanish Armada (1588)The Thirty Years War (1618 - 1648)• Utterly devastated Germany (1/2 of population dies)Thomas Hobbes (1588 - 1679): Apologist of Absolutism• homo lupus homini(Man is a wolf to man)• Need strong, absolutestate to keep societyin check and to preservepeace!Innovation: The Dutch Invent the Telescope • around 1600• soon to be used by GalileoInnovation: The Dutch Invent the Microscope • inception of microbiologyHugo Grotius (1583 - 1645): The Law of Nations• De iure belli ac pacis(Of the Law of War and Peace)• concept of Natural Law:man has certain unalienablerights• man is fundamentallysociableThe Making of the New Astronomy: Tycho and Kepler• Tycho Brahe: Greatest Observer of the Age• Johannes Kepler: Greatest TheoristTycho Brahe: The Great Danish Observer • 1546 (Skaane) – 1601 (Prague)• born into nobility:- lived privileged life• State-sponsorshipof Danish kingExtensive University Education: Wittenberg • Birthplace of Protestant Reformation! Martin Luther: 1517A Royal Patron: King Frederik II of Denmark • provides Tycho withgenerous, sustained fundingfor astronomical research• Construction of greatestobservatory in EuropeTycho’s Island: HvenBest pre-Tycho tables: Erasmus Reinhold (1511-53)• professor of mathematicsin Wittenberg• uses De Rev. to calculatenew tables of celestial motions• Prutenic Tables (1551)widely used• Indirect fame for CopernicusHven: UraniborgGreat Mural Quadrant• Pinnacle of naked-eyeobservations!Hven: StjerneborgTycho on Hven: Important Achievements• Precise (~4 arcmin) positions of planetsover extended period of time (used by Kepler)• Demonstrate that comets are superlunar (1577)• Demonstrate that (Super-) Novae are stellar (1572)• Failure to find stellar parallax- rejection of Copernican model (Tychonic model)• Establish regard for precision data in astronomyTycho’s Supernova of 1572Cassiopeia• Chandra sees remnant in X-rays• Tycho can prove that Nova is fixed wrt stars!The Comet of 1577• Big Q: Are comets sub- or supralunar?(According to Aristotle, they are atmospheric effects)The Comet of 1577• Tycho’s A: Comets are supralunar?Downfall of Aristotelian Physics• Tycho demonstrates: (Super-) Novae and Cometslocated beyond orbit of Moon (i.e., supralunar)• Thus: Heavens are not immutable(as claimed by Aristotle)•Only one (and the same) physics for heavenand EarthTycho asks anew: What about Stellar Parallax?• Copernican model predicts this!• Tycho’s precision data does not confirm this?Tycho rejects Copernicus’ Argument for missing parallax• If stars really were that distant:- vast empty space between Saturn and fixed stars- stars (apparent size known) would be too largeTycho asks anew: What about Stellar Parallax?• Stellar parallax not found!• Reason: Tycho’s star positions are accurateto within ~ 1 arcmin, but real parallaxes aresmaller that 1 arcsec (1/60 of armin)• Therfore: Tycho concludes that Earth does notmove?• But: Tycho is also aware of important advantagesof Copernican model (e.g., maximum elongationof Venus, simple explanation for retrogression)• What to do?The Tychonic World System• Geo-heliocentric (compromise) model!Equivalence of Tychonic and Copernican System• How to explain this motion relative to Earth?Equivalence of Tychonic and Copernican SystemCopernicusEquivalence of Tychonic and Copernican SystemTychoEquivalence of Tychonic and Copernican System• Relative motions are the same• Absolute position of Earth is different:- Tycho: Center of Universe, Earth does not move!- Copernicus: Earth moves, both rotation and revolution•Tycho’s system quickly became fashionable• Maintain advantages of Copernican model,but does not have to face conflict withtheory of motion (common-sense) and withScriptureTychonic System: Problem of Intersecting Spheres• Crystalline (solid) spheres of Mars and Sun intersect!Tychonic System: Problem of Intersecting Spheres• Comet of 1577: Tycho shows motion across celest. Spheres•Abandon concept of crystalline spheres altogether!Tycho: Journey’s End in Imperial Prague (1599)Tycho: Journey’s End in Imperial PragueRudolph II- Emperor (1576-1612)• Great Patron of Arts and Sciences (Tycho, Kepler)Tycho: Journey’s End in Imperial PragueBenatky Castle: Final Domicile (1599 – 1601)• Tycho invites upstart young Johannes Kepler!Tycho and Kepler meet in Prague (1600-01)• Tycho needs Kepler:- difficult calculationsto figure out orbit of Mars• Kepler needs Tycho:- precision data to figure out true orbitsof the planets• Together embark onimproved astron. tables(Tabulae Rudolphinae)Tycho: Journey’s End in Imperial Prague• Died 1601• Buried in Prague• Epitaph:“Neither wealth nor powerremain, only the arts andsciences”Kepler (part 1): Tycho Brahe• Tycho Brahe: - establishes precision observation into astronomy- shows that comets and supernovae are celestialphenomena (downfall of Aristotelian dogma ofimmutability of heavens)- abandons concept of solid (crystalline) sphere• Tychonic world system: geo-heliocentric model- compromise between Ptolemy and Copernicus(“Best of two worlds”)- can account for apparent absence of stellar parallax• Kepler inherits Tycho’s data after his death in


View Full Document

UT AST 350L - Lecture 8: Kepler I

Download Lecture 8: Kepler I
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Lecture 8: Kepler I and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Lecture 8: Kepler I 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?