Title: As the Earth revolves around the sun, differen
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2Observations
- Sun rises sets every day
- Sun rises in East sets in West
- Suns 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.
3Astronomy
4- 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...
5The 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.
6- 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 Moons
7- Galileo also observed the "phases of Venus" which
demonstrated that Venus orbited around the sun. - Lets draw some more.
8- The Heliocentric Theory explains all observations
made from Earth. - Heliocentric makes the sun the center of
attention rather than the earth. - And more drawing.
9- Here's an article written by Benjamin Franklin
about how much sense the Heliocentric Theory
makes - The Whimsical Cook
10 11The value of the space program
- 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
- 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
12- 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/hr
- Earth spins at 15 degrees per hr
13Time zones
- How to figure out what the time difference is and
are you E or W.
14The Earths 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
15- Revolution- to orbit around an object
- The Earth revolves around the sun in 365 ¼ days.
- Sidereal Day vs solar day
16As 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.
17- 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.
18Warning! 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
19Seasons
Not drawn to scale. The orbit is not shaped like
this.
20Lets make a chart of the 4 key dates and what
they each mean.
Date
Name
Key points
21Summer 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.
22Fall (autumnal) Equinox
- September 23
- Equal day and night
- Sun is directly over the equator
23Winter Solstice
- December 21
- N. Pole is tilted away from the sun
- Shortest day, longest night
- Sun is directly over the Tropic of Capricorn
24Spring (vernal) Equinox
- March 21
- Sun is directly over the Equator
- Equal day and night
25Zenith
Summer Solstice June 21
Equinoxen March 21/Sept 23
Winter Solstice Dec 21
26HW on Seasons Day/Night
27- Discussion of a more or less tilted world
28An Encarta Animation
OK, Girls Boys, time for an activity on seasons
and the tilt of the Earth!
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30Note
- The seasons are NOT caused by the distance from
the sun.
31See what the Earth looks like RIGHT NOW
32Lets see how the suns position changes
throughout the year
33Time for a lab
- Take out lab 8-3 Ellipses
34Lets see some ellipses
35Perihelion Jan 3 93,000,000 miles
Aphelion July 4 95,000,000 miles
Not drawn to scale! The shape is more like a
circle
36Keplers Laws
- 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 yourself
37- 2) 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
38March
April
February
May
June
January
July
August
September
December
October
November
39- 3) Relationship between distance and period
- P2 D3
- Where P is the Period in Earth Years
- And D is the distance in AUs
40- An AU is an astronomical unit, which is the
average distance from the sun to the Earth.
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42Two videos
- The Powers of Ten
- Bill Nye The Moon
43The Moon
- The 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.
44Phases of the moon handout
Sun way the heck to the left
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47Last Half/ Last Quarter
Waning Crescent
Waning Gibbous
New
Full
Waxing Crescent
Waxing Gibbous
First Half/ First Quarter
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49Notice 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.
50The Names of the Full Moons
Here are the traditional names given to each
month's full moon from the "Old Farmer's Almanac"
January Wolf Moon February Snow Moon March Worm
Moon April Pink Moon May Flower
Moon June Strawberry Moon
July Buck Moon August Sturgeon
Moon September Harvest Moon October Hunter's
Moon November Beaver Moon December Cold Moon
51Eclipses
- 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.
penumbra
Earth
umbra
moon
sun
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53- 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
sun
penumbra
umbra
Earth
54A view of a Solar Eclipse as Seen from Space
- http//www.stormcenter.com/media/060331/
55- Angular size of the moon activity
56Tides
- The strength of gravity depends on how close two
objects are and their masses.
m1 and m2 are masses of the objects d is the
distance
57Lets draw a diagram of how the moon causes
tides! Lets draw a diagram of what the tides
look like.
58- 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.
59The Planets
- Take out Lab 8-5 The Planets
The Solar System
60Time for a sing-a-long
61Comets
- Chunk 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!
62Meteors
- 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.
63Video on what causes a meteor shower
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69Stars
- Circumpolar and star trails
Circumpolar Constallations
70Stellar Fusion
71Hydrogen nucleus (Proton)
Helium
722.016
Mass1.008
Mass4.0026
Mass1.008
1.008 x 4 4.032
4.032 4.0026 .0294
73Emc2
E energy
m mass
c2 speed of light squared
.0294 x 186,000 x 186,000 a lot from a little
74Lab Stellar Classification
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77Short video on the formation of the Earth
78The Life of a Star
Cloud of gas Contracts Heats up Fusion
79If the star is 7x the sun or smaller Swell up to
a red giant Shrink to a white dwarf Slowly cool
and die
80If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
81If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
82If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
83If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
84If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
85If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
86If the star is 7x the sun or larger Swell up to
a red giant Shrink collapse and explode as a
supernova
87If 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
88Or better yet! A black hole!
89Time for a sing-a-long
90The Doppler Shift
91Lab Spectral Analysis
92Deep Space
93The End
94- If asked- Travel _at_ speed of light Encarta
animation (mind warping!)
95Spring March 21
Summer June 21
Winter Dec 21
Fall Sept. 23
96North Pole
NP 24hr LI 16hr Eq 12hr SP 0hr
Summer June 21
South Pole
97North Pole
NP 12hr LI 12hr Eq 12hr SP 12hr
Equinoxes March 21/ Sept23
South Pole
98North Pole
NP 0hr LI 8hr Eq 12hr SP 24hr
Winter Solstice Dec 21
South Pole