1 / 78

GE 150 Astronomy

GE 150 Astronomy. Week #6 February 19,21 2013. The Beginnings of Modern Astronomy. The use of Precision measurements and Telescopic Observations. Astronomers of 16 th century. Astronomy was often a pursuit of rich noblemen No gov’t funding

bryony
Download Presentation

GE 150 Astronomy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GE 150 Astronomy Week #6 February 19,21 2013

  2. The Beginnings of Modern Astronomy The use of Precision measurements and Telescopic Observations

  3. Astronomers of 16th century • Astronomy was often a pursuit of rich noblemen • No gov’t funding • Though interested in science, they still held on to beliefs we would call pseudoscience • Alchemy • Numerology • Astrology

  4. Polish Danish Italian German Greek Tycho Brahe (1546-1601) was

  5. Tycho Brahe (1546-1601) Probably died a virgin Had artificial wooden and silver noses Probably died of Mercury poising Rumored to have died of a bladder burst Was labeled a heretic by the church

  6. Tycho Brahe (1546-1601) is known for: First telescope observations of the sun First sun centered scientific model of the solar system or universe Being the world’s best naked-eye astronomer Creating first a theoretical model to explain planetary motions Creating first a theoretical model for explaining gravity

  7. Tycho Brahe (1546-1601 C.E.) • Built “meridian circle” to measure the positions of planets very accurately (~1 arc minute) Major Accomplishments: • Made the most continual and accurate observations of stars and planets (Mars) for his time

  8. Tycho Brahe (1546-1601 C.E.) Major Accomplishments: • Found that comets moved outside of the Earth’s atmosphere • Witnessed a supernova (1572) and concluded that it was much farther away than any celestial object • Couldn’t detect parallax motion in the stars

  9. the use parallax to measure distances

  10. Why were Tycho’s parallax distances important? Disproved ancient ideas about the heavens: The supernova in 1572 showed that the heavens were both changing and had a dimension of distance Comets were thought to be atmospheric occurrences, not objects in the region of the planets This troubled scholars who previously thought the heavens were unchanging.

  11. Tycho Brahe (1546-1601 C.E.) • Created his own hybrid geo-heliocentric model of the solar system - planets go around the Sun, but the Sun, in turn, orbits around the Earth

  12. Brilliant Geometer and MathematicianJohannes Kepler1571 - 1630

  13. Johannes Kepler 1571 - 1630 was : Polish Danish Italian German Greek

  14. Johannes Kepler 1571 - 1630 - Probably died a virgin Was a priest and Lawyer Probably died of Mercury poising Was blind at the time of his death Was labeled a heretic by the church

  15. Johannes Kepler 1571 - 1630 - None of these. He was a deeply religious man and a family man. Tycho Brahe’s assistant but rumored to have hated Tycho. Inherited Tycho’s data after his death. With that data he changed the understanding of motion of heavenly bodies forever. He was also a writer, who wrote children stories about the heavens.

  16. Johannes Kepler 1571 - 1630is known for - First telescope observations of the sun First sun centered scientific model of the solar system or universe Being the world’s best naked-eye astronomer Creating first a theoretical model to explain planetary motions Creating first a theoretical model for explaining gravity

  17. Johannes Kepler1571 – 1630Kepler’s Three Laws of Planetary Motion

  18. Kepler’s First Law: The orbit of a planet about the Sun is an ellipse with the Sun at one focus.

  19. Eccentricity:e • how squashed or “out of round” the ellipse is • a number ranging from 0 for a circle to 1 for a straight line e = 0.02 e = 0.7 e = 0.9

  20. Interactive on BB Vista

  21. What is the shape of Earth’s orbit around the Sun?Earth, e = 0.017

  22. Kepler’s Second Law: A line joining a planet and the Sun sweeps out equal areas in equal intervals of time.

  23. Interactive on BB Vista

  24. SECOND LAW • A line drawn from the planet to the Sun sweeps out equal areas in equal times • Consequences: • orbital speed is not constant for an ellipse only for a circle • planets move faster when near the Sun (perihelion) • planets move slower when they are far from the Sun (aphelion)

  25. THIRD LAW The size of the orbit determines the orbital period Planets that orbit near the Sun orbit with shorter periods than planets that are far from the Sun a3AU= P2years

  26. THIRD LAW The size of the orbit determines the orbital period Planets that orbit near the Sun orbit with shorter periods than planets that are far from the Sun

  27. Kepler’s Third Law

  28. SECOND LAW • The speed a planet travels during its orbit is related to the distance from the star • When the planet is near the sun the planet goes faster than when the planet is farther from the sun Planet travels slow here Planet travels fast here

  29. THIRD LAW • The size of the orbit determines the orbital period • planets that orbit near the Sun orbit with shorter periods than planets that are far from the Sun p = ~ 12 years p = 1 year

  30. THIRD LAW • The size of the orbit determines the orbital period • planets that orbit near the Sun orbit with shorter periods than planets that are far from the Sun • SIZE & MASS OF THE PLANET DOES NOT MATTER Both have p = 1 year

  31. The 2nd Law tells us what a particular planet does when it orbits a Star The planet will move faster when it is close to the Sun and slower when it is farther from the Sun The 3rd Law relates orbital periods to the orbital distances for all the planets in the Solar System planets orbiting nearer the Sun have short orbital periods Planets orbiting farther from the Sun have long orbital periods The Second and Third Laws

  32. The great scientist Galileo made discoveries that strongly supported a heliocentric cosmogony One of the principal founders of the experimental method for studying scientific problems. • Using a Dutch-designed telescope that he built himself, he made several observations that disproved ancient thinking about the Universe (1610)

  33. Galileo - 1564-1642 was - • Polish • Danish • Italian • German • Greek

  34. Galileo - 1564-1642 - • Probably died a virgin • Was a priest and Lawyer • Probably died of Mercury poisoning • Was blind at the time of his death • Was labeled a heretic by the church

  35. Galileo - 1564-1642 is known for - • First telescopic observations of the sun • First sun centered scientific model of the solar system or universe • Being the world’s best naked-eye astronomer • Creating first a theoretical model to explain planetary motions • Creating first a theoretical model for explaining gravity

  36. Saturn: A Being with Ears • Saturn is not a sphere. • Circles and spheres do not dominate the heavens.

  37. Milky Way • With a telescope, Milky Way resolves into thousands (billions) stars • Implication: the Universe is bigger than imagined.

  38. The Moon • The moon has craters and mountains. • The moon is not a “perfect” heavenly body.

  39. Sunspots • The Sun is not a perfect heavenly body. • The Sun rotates about its own axis. • More observations showed Sun’s axis is tilted, which varied with seasons and repeated annually: clue Earth was orbiting the Sun!

  40. Galileo discovered Venus went through phases like the Moon (new thru full) which showed that Venus must orbit the Sun and strongly supported a heliocentric model “Venus is clearly smallest when it in the full phase and largest when it is in the new phase. Then Venus must be very far from Earth when it is in the full phase and quite closes to Earth when in the new phase – which supports the argument that Venus is orbiting the Sun not Earth.”

  41. The Ptolemaic view of the phases of VenusNote the phases which are missing

  42. Heliocentric view of phases of VenusNote the full array of phases and varying size

  43. Galileo’s telescope revealed phases of Venus which could only occur IF Venus orbits the Sun.

  44. Galileo observed “stars” going around Jupiter on successive nights • Today – 4 largest moon’s of Jupiter are known as the Galilean Moons

  45. Galileo’s log showing observations of moons orbiting Jupiter instead of Earth.

  46. The many contributions of Galileo (too many to discuss here) http://brunelleschi.imss.fi.it/itineraries/indexgal.html IN MEMORY OF GALILEO

  47. ExplainingAstronomical Motion Introduction To Gravity

  48. Sir Isaac Newton (1642-1727) • Described the fundamental laws covering the motion of bodies • Had to invent his own mathematics (Calculus) to do it! • And he did most of it before his 24th birthday…

  49. Isaac Newton (1642 – 1727)was - Polish Danish Italian German British

More Related