Astronomy

Observations: Sun rises & sets every day  Sun rises in East & sets in West  Sun’s path in the sky is an arc  Sun is at different angular altitudes in the sky at different times.  The sun is never directly above (at zenith) in NY. 

Astronomy

The 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: 

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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. 

Jupiter’s Moons

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Galileo also observed the "phases of Venus" which demonstrated that Venus orbited around the sun.

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Let’s 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. 

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Here's an article written by Benjamin Franklin about how much sense the Heliocentric Theory makes: The Whimsical Cook

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The Columbia

The value of the space program           

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Personal Computers Colorization of black and white movies Solar powered calculators Aluminized bags for snack food Weather satellites Halogen lights for cars Sports domes Microwave Ovens Pocket calculators Phone calls by satellite Laser guided missiles "Mylar" balloons "Blue Blocker" sunglasses Digital watches and thermometers "DirecTV", "Dish Network", etc "Kevlar" for bullet proof vests "Mini Mag" flashlights Fishing line Fiber optics for phone calls "Vortec" engines in GM cars "Ovation" guitars and helicopter blades

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Medical scanners Electronic ignition in automobiles Laser scanners in stores "Bulb Miser" devices for long life light bulbs Weather Maps on television Juice boxes for "Hawaiian Punch", etc "The Patch" medical device Breathing systems for Mt. Everest climbers, Scuba divers and firefighters “Flexon" eyeglasses and dental braces Cellular phones and beepers Cable Television, H B O, Showtime, etc Pens that write upside down and under water Anti corrosive paint for bridges, boats & Statue of Liberty Scratch resistant coatings on sunglasses Football helmets for the NFL Pacemaker batteries that last 20 years and can be recharged through the skin. Compact Disks GPS Navigation Systems

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Rotation - to spin around an axis.

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How long does it take the Earth to spin once? How many degrees is a full spin? 360°÷24hours= 15°/hr Earth spins at 15 degrees per hr

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Time zones 

How to figure out what the time difference is and are you E or W.

The Earth’s Rotation does not have the same speed all over At the equator, rotation is

40,074 km/day or 1670 km/hr

At NY

31,200 km/day or 1300 km/hr

At the poles

0 km/day or 0 km/hr

Revolution- to orbit around an object  The Earth revolves around the sun in 365 ¼ days. 

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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 can’t 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. 

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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

Seasons Not drawn to scale. The orbit is not shaped like this.

Let’s make a chart of the 4 key dates and what they each mean. Date

Name

Key points

Summer Solstice June 21  N. Pole is tilted towards the sun  Sun is highest in the sky in NY  Longest day, shortest night  Sun is directly over the Tropic of Cancer. 

Fall (autumnal) Equinox September 23  Equal day and night  Sun is directly over the equator 

Winter Solstice December 21  N. Pole is tilted away from the sun  Shortest day, longest night  Sun is directly over the Tropic of Capricorn 

Spring (vernal) Equinox March 21  Sun is directly over the Equator  Equal day and night 

Zenith Summer Solstice June 21 Equinoxen March 21/Sept 23

Winter Solstice Dec 21

HW on Seasons & Day/Night

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Discussion of a more or less tilted world

An Encarta Animation

OK, 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 NOW

Let’s see how the sun’s position changes throughout the year

Time for a lab 

Take out lab 8-3: Ellipses

Lets see some ellipses

Perihelion Jan 3 93,000,000 miles

Aphelion July 4 95,000,000 miles

Not drawn to scale! The shape is more like a circle

Kepler’s Laws 

1) All planets travel in elliptical orbits with the sun at one focus.

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Note: The Earth's orbit is so close to a perfect circle that it can't be distinguished with the human eye. See for yourself

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2) Each planet travels in such a way that a line joining the planet and the sun sweeps equal areas in equal times.

Keppler’s Second Law

April

March February

May

June January

July

August

September

December October November

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3) Relationship between distance and period: P2 = D3

Where P is the Period in Earth Years And D is the distance in “AU’s”

An “AU” is an astronomical unit, which is the average distance from the sun to the Earth.

Two videos The Powers of Ten  Bill Nye: The Moon 

The Moon The moon revolves around the Earth once a month (moonth).  Moon rises 50 minutes later every day. 

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It can be seen during the day just about as much as the night.

Phases of the moon handout

Sun: way the heck to the left

L

R

Full

L

New

Waning Gibbous R

Waning Crescent

Last Half/ Last Quarter

Waxing Crescent

Waxing Gibbous First Half/ First Quarter

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 (eastwest) rocking is due to the changing orbital velocity of the moon.

The Names of the Full Moons Here are the traditional names given to each month's full moon from the "Old Farmer's Almanac": January February March April May June

Wolf Moon Snow Moon Worm Moon Pink Moon Flower Moon Strawberry Moon

July August September October November December

Buck Moon Sturgeon Moon Harvest Moon Hunter's Moon Beaver Moon Cold Moon

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A 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.

Earth

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penumbra umbra moon

Eclipses

sun

Earth

sun

umbra

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penumbra

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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. moon

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A view of a Solar Eclipse as Seen from Space 

http://www.stormcenter.com/media/06033 1/

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Angular size of the moon activity

Tides 

The strength of gravity depends on how close two objects are and their masses.

m1m2 F 2 d

m1 and m2 are masses of the objects d is the distance

Let’s 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 Planets 

Take out Lab 8-5: The Planets

The Solar System

Time for a sing-a-long

Comets 

Chunk of ice and dirt following an elongated elliptical orbit.

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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.

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Encarta Solar System: Great Comets!

Meteors Meteor 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

Stars 

Circumpolar and star trails Circumpolar Constallations

Stellar Fusion

Hydrogen nucleus (Proton) Helium

2.016 Mass=1.008

Mass=4.0026

Mass=1.008

1.008 x 4 = 4.032 4.032 – 4.0026 = .0294

E=mc2 E = energy m = mass c2 = speed of light squared .0294 x 186,000 x 186,000 = a lot from a little

Lab: Stellar Classification

Short video on the formation of the Earth

The Life of a Star Cloud of gas Contracts

Heats up Fusion

If the star is 7x the sun or smaller: Swell up to a red giant Shrink to a white dwarf Slowly cool and die

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova

If the star is 7x the sun or larger: Swell up to a red giant Shrink collapse and explode as a supernova Dies as a rapidly spinning core…

Or better yet! A black hole!

Time for a sing-a-long

DVD:

The Right Stuff

The Doppler Shift

Lab: Spectral Analysis

Deep Space

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If asked- Travel @ speed of light: Encarta animation (mind warping!)

Spring March 21

Summer June 21

Winter

Dec 21 Fall Sept. 23

North Pole

NP 24hr LI 16hr

Summer June 21

Eq 12hr SP 0hr

South Pole

North Pole

NP 12hr LI 12hr

Equinoxes

Eq 12hr

March 21/

SP 12hr

Sept23 South Pole

North Pole

NP 0hr LI 8hr

Winter Solstice

Eq 12hr

Dec 21

SP 24hr

South Pole