Astronomy

WinterDec 21SummerJune 21SpringMarch 21FallSept. 23Observations:Sun rises & sets every daySun rises in East & sets in WestSuns path in the sky is an arcSun is at different angular altitudes in the sky at different times.The sun is never directly above (at zenith) in NY.AstronomyThe Geocentric theory explains all of these phenomena. Since movement of the Earth cannot be felt early scientists thought that the Earth was stationary and everything else moved around us.The geocentric theory says that the Earth is at the center of the solar system/ universe.Lets draw a little...The Geocentric Theory does not explain this:Foucault Pendulum: The first good evidence of the Earth's rotation was provided by a swinging pendulum. The pendulum would continue to swing in the same direction while the Earth rotated beneath it. A more recent source of evidence of rotation is the swirling pattern of weather systems seen by satellites. The Coriolis Effect makes the Foucault Pendulum work. The rotation of the Earth puts a "spin" on the air movement which causes a curve in the travel direction. In the Northern Hemisphere the turn is towards the objects right.

Galileo disproved the geocentric theory. He was the first to turn the telescope to the sky (he did not invent the telescope) for the purposes of Scientific observations. The moons of Jupiter orbit an object other than Earth. Galileo noticed that the four visible moons of Jupiter appeared to orbit around Jupiter and therefore did not revolve around the Earth. Jupiters MoonsGalileo also observed the "phases of Venus" which demonstrated that Venus orbited around the sun.Lets draw some more.The Heliocentric Theory explains all observations made from Earth. Heliocentric makes the sun the center of attention rather than the earth.And more drawing.Here's an article written by Benjamin Franklin about how much sense the Heliocentric Theory makes:

The Whimsical Cook

The Columbia

The value of the space programPersonal ComputersColorization of black and white moviesSolar powered calculatorsAluminized bags for snack foodWeather satellitesHalogen lights for carsSports domesMicrowave OvensPocket calculatorsPhone calls by satelliteLaser guided missiles"Mylar" balloons"Blue Blocker" sunglasses Digital watches and thermometers"DirecTV", "Dish Network", etc"Kevlar" for bullet proof vests"Mini Mag" flashlightsFishing lineFiber optics for phone calls "Vortec" engines in GM cars"Ovation" guitars and helicopter blades

Medical scannersElectronic ignition in automobilesLaser scanners in stores"Bulb Miser" devices for long life light bulbsWeather Maps on televisionJuice boxes for "Hawaiian Punch", etc"The Patch" medical deviceBreathing systems for Mt. Everest climbers, Scuba divers and firefightersFlexon" eyeglasses and dental bracesCellular phones and beepersCable Television, H B O, Showtime, etcPens that write upside down and under waterAnti corrosive paint for bridges, boats & Statue of Liberty Scratch resistant coatings on sunglassesFootball helmets for the NFLPacemaker batteries that last 20 years and can be recharged through the skin. Compact DisksGPS Navigation Systems

Rotation - to spin around an axis.How long does it take the Earth to spin once?How many degrees is a full spin?36024hours= 15/hrEarth spins at 15 degrees per hrTime zonesHow to figure out what the time difference is and are you E or W.At the equator, rotation is 40,074 km/day or 1670 km/hrAt NY31,200 km/day or 1300 km/hrAt the poles0 km/day or 0 km/hrThe Earths Rotation does not have the same speed all over

Revolution- to orbit around an objectThe Earth revolves around the sun in 365 days.Sidereal Day vs solar day

As the Earth revolves around the sun, different constellations are visible in the night sky.As viewed from Earth, the sun is passing through Leo (even though you cant see the stars during the day.The Axis of Rotation is the imaginary line that the Earth turns about.The axis always points to the North Star. This is called Parallelism of the Earth's axis. The imaginary surface of the Earth's yearly trip around the sun is the Plane of Earth's Orbit.Warning! The following statement sounds crazy but you'll understand it if you read it slowly!"The axis is tilted by 23.5 from the perpendicular to the plane of its orbit." Demonstration

SeasonsNot drawn to scale.The orbit is not shaped like this.Lets make a chart of the 4 key dates and what they each mean.DateNameKey pointsSummer SolsticeJune 21N. Pole is tilted towards the sunSun is highest in the sky in NYLongest day, shortest nightSun is directly over the Tropic of Cancer.Fall (autumnal) EquinoxSeptember 23Equal day and nightSun is directly over the equator

Winter SolsticeDecember 21N. Pole is tilted away from the sunShortest day, longest nightSun is directly over the Tropic of Capricorn

Spring (vernal) EquinoxMarch 21Sun is directly over the EquatorEqual day and night

Winter SolsticeDec 21EquinoxenMarch 21/Sept 23Summer SolsticeJune 21ZenithHW on Seasons& Day/NightDiscussion of a more or less tilted worldAn Encarta AnimationOK, Girls & Boys, time for an activity on seasons and the tilt of the Earth!

Note:The seasons are NOT caused by the distance from the sun.See what the Earth looks like RIGHT NOWLets see how the suns position changes throughout the yearTime for a labTake out lab 8-3: EllipsesLets see some ellipsesAphelion July 4 95,000,000 milesPerihelion Jan 3 93,000,000 milesNot drawn to scale! The shape is more like a circle

1) All planets travel in elliptical orbits with the sun at one focus. Note: The Earth's orbit is so close to a perfect circle that it can't be distinguished with the human eye.See for yourselfKeplers Laws2) Each planet travels in such a way that a line joining the planet and the sun sweeps equal areas in equal times.Kepplers Second Law

JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember3) Relationship between distance and period: P2 = D3

Where P is the Period in Earth Years

And D is the distance in AUsAn AU is an astronomical unit, which is the average distance from the sun to the Earth.

Two videosThe Powers of TenBill Nye: The MoonThe moon revolves around the Earth once a month (moonth).Moon rises 50 minutes later every day.It can be seen during the day just about as much as the night.The MoonPhases of the moon handout

Sun: way the heck to the left

RL

RLNewWaxing CrescentFirst Half/ First QuarterWaxing GibbousFullWaning GibbousLast Half/ Last QuarterWaning Crescent

Notice the changing diameter of the Moon during the 'moonth'. As the Moon's orbit brings it closer to earth (perigee) at the New Moon, it appears larger to us. Also notice how the Moon 'rocks' up and down and back and forth. That happens because the Moon's orbit takes it above the Earth's equator (allowing us to see more of the south polar region) and below the equator revealing more of the north polar region of the Moon. The back and forth (east-west) rocking is due to the changing orbital velocity of the moon.

The Names of the Full MoonsJanuaryWolf MoonFebruarySnow MoonMarchWorm MoonAprilPink MoonMayFlower MoonJuneStrawberry MoonHere are the traditional names given to each month's full moon from the "Old Farmer's Almanac":JulyBuck MoonAugustSturgeon MoonSeptemberHarvest MoonOctoberHunter's MoonNovemberBeaver MoonDecemberCold MoonEclipsesA lunar eclipse occurs when the Earth blocks out the Moon's sunlight. The moon goes into the Earth's shadow.Lunar eclipses happen during a Full Moon.

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A solar eclipse is when the moon blocks sunlight from reaching the Earth. Solar Eclipses happen during a New Moon. Eclipses do not occur every time there is a full or new moon because the moon's orbit around the Earth is inclined.sunEarthmoonumbrapenumbraA view of a Solar Eclipse as Seen from Spacehttp://www.stormcenter.com/media/060331/

Angular size of the moon activityTidesThe strength of gravity depends on how close two objects are and their masses.

m1 and m2 are masses of the objectsd is the distance Lets draw a diagram of how the moon causes tides!

Lets draw a diagram of what the tides look like.A Spring Tide is caused by a full moon and a new moon. The water springs from its highest level to its lowest for the month.A Neap Tide is caused by the half moon phases. The high tide is not so high and the low is not so low.The PlanetsTake out Lab 8-5: The PlanetsThe Solar SystemTime for a sing-a-longCometsChunk of ice and dirt following an elongated elliptical orbit. DVD Weather- Wind Chp 9 (Solar Wind)Has a tail only when it comes close to the sun. The heat melts it and the solar wind sweeps the tail away.The tail always points away from the sun. Encarta Solar System: Great Comets!MeteorsMeteor Showers result mainly from debris from the orbit of the comet. If the Earth crosses the path, the debris will fall to Earth as a visible meteor or shooting star. If the rock is big enough it will survive the fiery entry into the atmosphere and hit the surface as a meteorite. Video on what causes a meteor shower

StarsCircumpolar and star trailsCircumpolar ConstallationsStellar FusionHydrogen nucleus (Proton)HeliumMass=1.0082.016Mass=4.00261.008 x 4 = 4.0324.032 4.0026 = .0294Mass=1.008E=mc2E = energym = massc2 = speed of light squared.0294 x 186,000 x 186,000 = a lot from a littleLab: Stellar Classification

Short video on the formation of the EarthThe Life of a StarCloud of gasContractsHeats upFusionIf the star is 7x the sun or smaller:Swell up to a red giantShrink to a white dwarfSlowly cool and dieIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernova

If the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaIf the star is 7x the sun or larger:Swell up to a red giantShrink collapse and explode as a supernovaDies as a rapidly spinning coreOr better yet!A black hole!Time for a sing-a-longThe Doppler ShiftDVD: The Right StuffLab: Spectral AnalysisDeep SpaceThe EndIf asked- Travel @ speed of light: Encarta animation (mind warping!)

Summer June 21North PoleSouth PoleNP 24hrLI 16hrEq 12hrSP 0hr

EquinoxesMarch 21/Sept23North PoleSouth PoleNP 12hrLI 12hr Eq 12hrSP 12hr

Winter SolsticeDec 21North PoleSouth PoleNP 0hrLI 8hrEq 12hrSP 24hr