Observations:

2. 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.

3. Astronomy

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...

5. 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.

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. Jupiter’s Moons

7. Galileo also observed the "phases of Venus" which demonstrated that Venus orbited around the sun. • Let’s 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. The Columbia

11. 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 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 The value of the space program

12. Rotation - to spin around an axis. • 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

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

14. 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

15. Revolution- to orbit around an object • The Earth revolves around the sun in 365 ¼ days. • Sidereal Day vs solar day

16. 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.

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.

18. 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

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

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

21. 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.

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

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

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

25. Zenith Summer Solstice June 21 Equinoxen March 21/Sept 23 WinterSolstice Dec 21

26. HW on Seasons & Day/Night

27. Discussion of a more or less tilted world

28. An Encarta Animation OK, Girls & Boys, time for an activity on seasons and the tilt of the Earth!

30. Note: • The seasons are NOT caused by the distance from the sun.

31. See what the Earth looks like RIGHT NOW

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

33. Time for a lab • Take out lab 8-3: Ellipses

34. Lets see some ellipses

35. 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

36. Kepler’s 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. Keppler’s Second Law

38. March 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 “AU’s”

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

42. Two videos • The Powers of Ten • Bill Nye: The Moon

43. The 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.

44. Phases of the moon handout Sun: way the heck to the left

46. R L

47. R L Last Half/ Last Quarter Waning Crescent Waning Gibbous New Full Waxing Crescent Waxing Gibbous First Half/ First Quarter

49. 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.

50. 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 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