Astronomy Study of objects in space such as the Sun,stars, planets, comets, gas, & galaxies. *Also, the Earths place in the universe. Universe = everything that exists Astrology is NOT science !!!
Disclaimer: Astrology is NOT science !!! There is currently no evidence that star positions affect humanbehavior or your future. Go ahead & read your horoscope but remember that it is just entertainment! Geo-centric Helio-centric
Earth-centered view of universe Sun-centered view of solar system C. Ptolomy 90-168 N. Copernicus modern view of the solar system: the Sun is a star planets orbit the Sun Galaxies = groups of billions of stars
there are more than 100 billion galaxies they all have different shapes Spiral Elliptical Irregular Universe Galaxies Cosmic Size Solar systems Stars
Star clusters & Constellations Solar systems Stars Planets, moons Asteroids, meteors, meteorites, comets The Big Dipper constellationis a pattern made of 7 stars watch this! Powers of Ten Video Apple in the Dark Imagine you are sitting at a table with a red apple in front of you.Yourfriend turns off all the lights.It is totally dark in the room.There areno windows in the room or crack around the door.No light can enterthe room. Write the statement you believe best describes how you would see theapple in the dark & explain your answer in a short paragraph. You will not see the red apple, regardless of how long you are in theroom. You will see the red apple after your eyes have had time to adjust tothe darkness. You will see the apple after your eyes have had time to adjust to thedarkness, but you will not see the red color. You will only see the shadow of the apple after your eyes have hadtime to adjust to the darkness. You will see only a faint outline of the apple after your eyes have hadtime to adjust to the darkness. Light: Electromagnetic spectrum & Doppler Shift
spectrum on: p. 484 & 678 Light:Electromagnetic spectrum & Doppler Shift Spectrum: light separated into component wavelengths
Learning from Light What is white light? What is a prism? Is there light we cant see? What is ROY G. BIV? Spectrum:light separated into component wavelengths spectrum on: p. 484 & 678 Electromagnetic Energy energy that travels in waves
spectrum on: p. 484 & 678 Draw your wave: Gamma Rays 1 cm X Rays 2 cm Ultraviolet 3 cm
Visible Light4 cm Infrared 5 cm Microwaves6 cm Radio Waves7 cm spectrum on: p. 484 & 678 The Electromagnetic Spectrum Earths Seasons = caused by the tilted axis (23.5o)
Equinox = equal hours of daylight & darkness Solstice = longest day & shortest day Fall Sep. 21 SUN Dec. 21 Jun. 21 (shortest day) (longest day) Mar. 21 Spring How we see the universe:
this is a RADIO TELESCOPE we use this information to study galaxies Types of spectra Sunlight, light bulbs
Sunlight that has traveled through our atmosphere Hot gas Doppler Effect wavelength changes if an object is moving toward or away from you
pitch gets higher Whitney Houston !!! BASS !!! pitch gets lower Doppler shifts from stars
Doppler Effect Song by Astrocapella The Expanding Universe
1929 Edwin Hubblefound that theuniverse is expanding Estimated distances, relative brightness, Doppler red shifts Hubbles Law:galaxies are moving away from us (red-shift) at a speed that is proportional to their distance the more distant the galaxy, the greater the velocity (moving away at faster speeds) Big Bang Theory At one time, the universe was a hot, superdense ball smaller than an atom. About 13.7 billion years ago, a rapid expansionoccurred sending material in all directions. This was the beginning of the universe. Eventually, matter cooled & condensedinto galaxies, stars, & planets. Support for the Big Bang Theory
Red shifts Cosmic background radiation (CBR) Signals coming from every direction in space. Radio, microwave, infrared, & X-rays. Believed to be created by the big bang expansion. Video Cosmic Background Radiation (CBR)
The hypothesis that the universe hasalways been expanding (since the BigBang) predicted (1948) that radiationproduced from the first moment ofexpansion would permeate the universe. In 1965 this radiation was discovered In 2003 astronomers studying the CBRdetermined the universe is 13.7 billionyears old Incandescence: glowing from heat
Blue = hottestRed=coolest A cloud of space dust or gas.
Nebula A cloud of space dust or gas. Nebular Hypothesis cloud of mostly hydrogen & helium A. nebula A. B.
Started rotating & collapsing toward center because of gravity forming an accretion disk , also the Sun forms C. rocky & metallic materials form as nebula cools D. collisions of particles created asteroid-sized objects (protoplanets or planetesmals) E. Sun = most dense object, nuclear fusion Rock / Terrestrial planets= more dense, heavy material, closer orbit Gas / Jovian planets = least dense, lighter material, farther orbit B.accretion disk C.cooling D.protoplanets E.solar system Earths Motions Rotation Revolution
spinning of Earth from west to east on an axis results in day / night Earth makes one rotation in 24 hours Revolution Earth moves around the sun every 365 days Earths Motions Precession
The change in direction of the northern axis North star is different Nutation Slight wobble, or change, in Earths axis from 23.5 Very slow movement due to the gravity of the moon Earths Motions Winter closest to the sun
Summer farthest from the sun Lunar Eclipses Occurs during full moon phases
Do not see the moon because the Earth blocks light Sun, Earth, moon in a line Solar Eclipses Occurs when sun is blocked by the moon Sun, moon, Earth
If the moon is partially blocking the sun, a partialsolar eclipse will occur Equatorial Bulge The Earth is not completely round
There is a bulge at theequator because ofrotation Video Link Keplers Laws 1st Law: orbital paths are ellipses (ovals)
Sun is at one focal point Animation of Laws Keplers Laws 2nd Law: a planet sweeps out equal areas in equal times Keplers Laws 3rd Law: T2 = d3 T= time of orbit
d = distance (avg) from the sun Barycenter The point between two objects where they balance each other
The actual center ofour solar system The sun orbits aroundthis point Barycenter Video Music :) Energy Nuclear Fission Nuclear Fusion
The splitting of an atom tocreate energy Produced in nuclearreactors The fusion of two atoms tocreate energy Happens within stars Cosmic Speed Limit Speed of light = 300,000 km/s
Light-year = the distance light travels in one year (9,500,000,000,000 km) The 2nd nearest star is 4.3 light years away(Alpha Centauri = triple-star system)