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78 Cards in this Set
- Front
- Back
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Cave paintings |
cave painting sights are aligned to be illuminated by the setting sun during winter solstice |
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constellations |
connect bright points or dark regions into pics tell stories of how they are related useful today to refer to parts in the sky |
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constellations are not |
real physical groupings of stars are not same all around most astronomers don't know them |
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predicting the future |
-Chinese started keeping records of the sky in 400 BCE -they were interested in guest stars (comets) -They saw that it was visible even in the day for multiple months -Supernova that caused the Crab Nebula |
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Eclipses |
-=sun moon and earth have to be lined up -moons orbit tilted from earths- has to be at a node -suns gravity makes the plane of moon's orbit rotate- node keeps moving -babylonians knew about this in BCE |
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Demonstrate or claim power |
-Incan- sun will rise between two towers on summer solstice -spirng and fall exquinox snake will go down the Mayan Temple of Kukulkan -Chinese had the circumpolar stars wheel behind emperors throne |
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Navigation |
-height of the North star = latitude -polynesian navigators used latitude hooks |
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Calendars and time keeping |
-stone hedge- summer solstice sunrise vise versa for winter solstice sunset -Chaco canyon- shaft of light through two stone slabs on a carved rock on summer solstice |
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Saanich Moons |
-local Saanich people (WSANEC) different name for each moon of the year -traditions associated with each |
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Australian aboriginal astronomy |
-myths, navigation, calendars, tides etc... -astronomy project: elders and astronomers work together |
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written accounts |
-Dresdan Codex: mayan book -tables of lunar eclipses and movements of Venus -records from conquistadores (Mayan) |
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Antikythera Mechanism |
-greek artifact -30+ interlocking gears with inscriptions -analogue computer to calculate positions of the sun, moon, moon phases etc... -didnt really work |
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statistics |
-Great Britain has 100+ stone circles -distribution is not random -lined up on purpose for a reason -the sky changes |
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precession |
-direction of earths axis changes from gravitational twisting forces from the sun and moon -full cycle every 26,000yrs -pole star changes |
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proper motion |
stars move sun orbits the centre of the galaxy |
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Why do we care? |
astronomy:historical records (comets, supernova) social sciences:date historical events education:common misconceptions |
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geocentric universe (wrong) |
earth (geo) is the centre of the uni common model in ancient times |
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Why isnt there a strong wind if Earth is moving |
atmosphere is held in place b/c of gravity and moves with it |
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Why doesn't out view of the stars change |
it does but they are far away so we dont notice |
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ancient greek astronomy |
700 BC constellations in writings flat earth surrounded by Ocean River cylindrical earth and rings of fire anti earth |
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classical greek astronomy |
-four mathematical arts: astro, music, geo, math -plato basis of philosophical education |
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Eudoxan Model |
-Eudoxus:27 concentric spheres rotating in various directions -Callippus- 7+ spheres to account for more data -Aristotle: unrolling spheres - wouldn't transfer their motion to eachother |
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outer planets are brightest when |
they're closest to us and fainter when further away |
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When are inner planets brightest |
combination of distance and phase |
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other planets move in their orbits |
we overtake and are overtaken by them -cars on a highway |
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Aristarchus of Samos |
-First known heliocentric model -proposed the stars were other suns |
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Deferents and Epicycles- Apollonius of Perga |
-planets travel on small circles and carried about the Earth on bigger circles |
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Deferents and Epicycles- Hipparchus |
had access to amazing observations of the Babylonians |
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Claudius Ptolemy |
-equant point to explain why planets speed up and slow down -wrote most influential scientific text -put the universe in order |
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fall of rome |
-Roman Empire reached its max extent 117 CE -fewer people spoke --> could read greek -dark ages not much history recorded |
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Medieval islamic astronomy |
-Islamic golden age:cultural, economic and scientific advances -Improvements to sundials, astrolabes and quadrants -practical use-time and direction of prayers |
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Geocentric refinements |
-Ptolemy's Great Treatise translated into almagest -books written to improve model -Tusi-couple to replace the equant |
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nicolaus coperniucus- celestial spheres |
earth is not special all planets go around the sun stars are very far away earth is spinning earth's motion accounts for other things rising setting etc.. |
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copernican model |
circular orbits- epicycles didnt match data better couldn't prove it |
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Copernicus' impact |
little published in the yr of his death wrote latin- not many could read mild disapproval from church |
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Tycho Brahe model |
pre telescopic thought distances to stars would be absurd geoheliocentric system- sun goes around the earth but everything else goes around the sun |
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Galileo Galilei |
built his improved model of the telescope |
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what did Galileo see? |
moon has mountains like Earth jupiter has moons orbiting it Venus goes through phases Sun has spots and is rotating |
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Galileo results |
Sidereus Nuncius wrote in Italian so people could read it heliocentric model support explains why bible conflicts |
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Catholic church reaction to Galileo |
-still not proof -he doesnt have enough proof -protestants didnt like it and were scheming |
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Dialogue concerning the two chief world systems |
Pope's ideas- character simplicio popular passed Inquisition's censors but then banned |
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Copernican revolution |
1686- conversations of the plurality of worlds was popular 1758:Heliocentric books were unbanned 1992: Pope apologized |
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refracting telescope |
-one lens -lens gathers rays -chromatic abberation -both lens and interior must be perfect -outside lens support |
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reflecting telescope |
-two mirrors -lens to produce magnified image -no chromatic aberration -light doesnt pass through |
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types of reflecting telescopes |
Prime focus Newtonian focus Cassegrain focus Nasmyth focus |
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Modern reflectors |
CFTH Gran Telescopio Canarias |
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CCDs |
-astronomers don't look through telescopes -charge coupled devise- like digital camera -read charge to find how many photons |
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Bigger mirror is better |
-more light you can collect- see fainter things -less its opening bends incoming light waves-better resolution -segmented to reduce weight |
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Uraniborg and Stjenrneborg |
-Tycho Brahe got an island -research complex was built -complete records of stars and planets- very accurate |
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angular measurements |
-width of pinky is about 1 degree -1/60th of that is 1 arcminute -1/60th of that is 1 arcsecond |
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Kepler |
weak vision and crippled hands astronomy theorist |
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Kepler and Tycho |
-tycho fallen out of favour with the new Kind of Denmark- Roman Emperor took him in -Kepler visited and left after a fight -Tycho died and kepler inherited his position and data |
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archival data |
time on telescopes is hard to get and $$$ data goes into common domain after 1yr |
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Kepler's data |
-figured out diff distances from Earth and other planets at diff times -Earth and other planets must be moving -published tables |
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paralax |
-how Kepler found his data -more distance between to objects originally -means less movement -closer distance between objects originally means more movement |
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Kepler's first law |
planets more in ellipses not circles with sun at one focus |
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Ellipses |
twi foci and semi major axis not a circle more oval |
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Eccentricity |
how flattened is the ellipse |
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most planets other than Mercury and Mars eccentricity |
orbits of planets have ow eccentricity- almost cirlces |
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Kepler's second law |
imaginary line connecting the Sun to any planet sweeps out equal areas of the ellipse in equal intervals of time -close to the sun they move faster vs slower further out |
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Kepler's third Law |
length of time for a planet to go around the sun once is related to distance from the sun -P2 = a2 -p= period, time for one orbit, Earth yrs -a= semi major axis, average distance to sun, AU |
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Transits of Venus |
-1761 -during 7yrs war |
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Newton's first law |
every body is in a state of being at rest or moving unless it is compelled to change its state by force |
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friction and intertia |
Friction: force that stops something Inertia: an object that is moving and will continue until it is forced to stop ie: fast car stopping suddenly and you keep moving forward until you are stopped by seatbelt |
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Speed VS Velocity |
speed: how fast you're going velocity: how fast you're going and which direction change= force acting on it |
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Newton's Second Law |
force acts on a body it produces the acceleration equal to force divided by mass acceleration = force/mass force= mass x acceleration |
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acceleration |
change in velocity |
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velocity |
speed and diraction |
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more force |
bigger change |
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more massive body |
smaller change |
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Newton's Third Law |
to every action there is and equal and opposite reaction |
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size matters- masses are diff accelerations will be too |
smaller things get bigger change
bigger things get smaller change |
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law of gravity |
Fg (infinity sign) m1m2 ______ r2 every particle of matter attracts every other particle. Is attracted by force that is proportional to product of the masses of particles |
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Newton and gravity |
1666- worked o motion and gravity during the plague got busy with other stuff he sends the Royal Society the Principa and they publish it |
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Newton's Cannonball |
Throw a ball and it will fall to Earth throw it harder and it will fall further away throw it hard enough and it will orbit |
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Newton and Kepler's Laws |
Newton backed up Kepler's laws on physics and math |
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Newton and Kepler's first law |
planets move in ellipses not circles with the centre of mass of the planet sun system at one focus |
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Newton and Kepler's third law |
Kepler: length of time for a planet to go around the sun once is related to its distance from the Sun Newton: different relationship |
