Chapter one and two book and class notes for Kalamazoo Central High School Astronomy Tri3

1. • ASTRONOMY PRE ASSESSMENT
• 3/20/2012 5th

2. ASTRONOMY
“Star” “Nam i n g”

3. Modern Astronomy
• Study of the known Universe
beyond our Atmosphere
• UNIVERSE
– “O n e ” “R o t a t e d ”
–The totality of everything that
exists.

4. God Virtu Plane m Pro s
o al tariu gram
• Stellarium
• Cartes Du Ciel

5. A study in
• We aPERSPECTIVEe
r e liv in g t h in g s o n t h
p la n e t E A R T H 24 hours
365 days
– Which Rotates about its axis every
S OL
– Which Revolves around our star every
• O u r s ta r,
– Is an average sized / powered star.
– With M a n yMilky Way Core
satellites revolving around it.
– Revolves around the every 240
million years
• M ilk y W a y G a la x y
– Member of a local cluster of galaxies

6. Picture 4
Difficulties of
Teaching/Learning
Astronomy
Incorrect Prior Knowledge
Topics are of magnitudes that
most students have difficulty
grasping cognitively
Topics are sometimes VERY
theoretical and difficult to see

7. Video Notes
• N a rra te d
B y:
– T im o t h y
TOPICS TO WATCH FOR: F e r r is
WHAT ARE THE BIG IDEAS?

8. COSMOLOGY
•“Order” – “Study of”
• S tu o the natu o the
dy f re f
U niv rse
e
–Including history,
function and future

9. COSMOLOGY
•Difficult, due to
limitations of
evidence.
•Borders on religious
study
•Myths/ Legends /

10. HOMEWORK
• WR I TE A
S U M M A R Y OF
YOU R
CR EA TI ON
M YTH

11. IN THE
BEGINNING...
• Humankind tried to explain the world in a
manner that they could understand.
• They made up explanations based on
their experiences
• The stories for the explanations often
used stars in the sky
• COSMOS: 7 – 9:00 – 15:00

12. COMPARING MYTHS
• MAKE A VENN DIAGRAM
• 2 or 3 myths
• Show SHARED TRAITS of the Myths
& Unique aspects of the Myth

13. Astrology
• “S tu o the stars”
dy f
• B e f that the astro m o rre s
lie no ical ccu nce
hav a dire im o H u an e e
e ct pact n m v nts.
• Zodiac
• “Circle o A nim
f als”
• CON S TEL L A TI ON S :
• “S tars To the
ge r”

14. At5 lg. I GB
sr oy
o
• Studied the Heavens for a
PURPOSE.
– Telling stories
– Telling Time
• Main objects of Study:
– Sun
– Moon
– Stars
– ?Earth?

15. Ancient Astronomy
• Ancient Greece
– 500 BC – Height o Classical Grek
f e
S cie .
nce
–Pythago
ras –
• Deduced Earth was a SPHERE
• Earth is a Perfect place,
requiring a Perfect Shape.
–A risto –
tle
• Interpreted Earth was a SPHERE
• Shadow of a eclipse is always a
spherical Arc
• Travelers south saw new
constellations

16. Ancient Astronomy
• Alexandria – Grek-fo nde city in
e u d
Egypt
– Great Library – Center of
Learning for the ancient
world.
–Erato ne
sthe s –
• Found an account of a well
to the south that had NO
shadow on the summer
solstice.
• He knew that on the same
day, there WAS a shadow in
elexandria.

20. θ = tan (A/O)
-1
360
=
Circumf erence
Angul ar Dis tance Between
Dis tance Between val ue) −
( experimental
( true val ue)
% error = ――――――――― × 1 00
true val ue

21. Angle of Sun at Kalamazoo (θ) =
Angular Distance between Overhead & Kalamazoo = 42.32 - θ
Circumference of the Earth
% ERROR (find true value from Mr. K)

22. ACTUAL
Circumference
• TRUE VALUE =
• 24,901miles
• 40,074,274 m
• COMPUTE % ERROR
• On the Back, Write an explanation
of what you believe your sources
of Error might be

23. Eratosthenes
• .4% Error
• Due to construction of wall or well
• Sun was not DIRECTLY overhead at the
well. A few degrees off
• Distance walked ???
• His number was lost when Library was
burned.
• Arabs saved text, rediscovered in 1500s

24. Computational Astronomy
• ANGULAR MEASURE
– Objects at great distances, we cannot
measure directly
• INDIRECT EVIDENCE
• ALGEBRA
– Ratios and comparisons between
knowns and unknowns
• GEOMETRY
– The universe has som regularity of form
– Triangulation
– Spheres, Circles, Ellipses

26. Eratosthenes pt. 2
• Compute the Circumference of
an Unknown circlegiven
Distance between 2 points and a
sun angle
• After each group has computed
for Circumference, we will
CONSTRUCT the circle and
measure TRUE Circumference.

27. Eratosthenes
• R e ne that 2 diffe nt angle o
aso d re s f
shado M U S T man that the w a
w e re as
cu e to the Earth
rv
• R e ne that the cu e co ld be that o
aso d rv u f
a S PH ER E.
• M athe atically K N EW that the
m
R A TI O o the arc distance to the
f
w le sphe M U S T be the sam as the
ho re e
R A TI O o the angu distance to 30
f lar 6
de e
gres

28. θ

29. THE PLAN
• FINISH MEASURES & COMPUTATION
• CUT OUT ARC
• Bring to front to tape together
• Compute Error
• Answer Error Analysis Question
• Hand into basket.
• Formula Manipulation discussion

30. Eratosthenes – Using the known
to determine the Unknown
• He knew the arc. Dist & Angle
• He assumed this ratio would be the same
for the full sphere.
• Could mathematically infer the
Circumference.
• OUR EXAMPLE –
– I will Measure DIAMETER, & use C= πd
– ALSO will attempt to use string to
measure TRUE Circumference

31. Using ANGULAR SIZE to determine true
size
• The closer to an object,
Larger
the ______ it appears.
• We can measure the ANGLE
• We MAY be able to find Distance
• THEN we can find the WIDTH
or DIAMETER of the object

32. The Moon Illusion
• Effect: the moon APPEARS larger when near
the Horizon

33. The Moon Illusion
• Effect: the moon APPEARS larger when near the Horizon
• Cause: Object appear larger in seen in
conjunction with a VANISHING POINT

37. Construction of a Clinometer
• Purpose: To measure angles above the
Horizon.
• Construction:
– Specialized Protractor
• Cut out
– Sight tube.
• Straw
– Gravity Indicator.
• <1 m string
• Washer or nut

38. Clinometer Lab
• Follow Lab procedures 2-6
For Object 1
• Do analysis & Conclusion
for Object 1
–(Average & %Error)
• Get Work Checked
• Follow Lab procedures 2-6
For Object 2

39. BE F O R E
S C IE N C E :
•MYSTICISM / GODS:
–Phenomena were explained
through gods and hocus-pocus

41. God,
the
G e ome
te r

42. Picture 4
Cosmology
pt 2

43. Backbone of Night-
Cosmos VII:
What explained the world
before science?
COSMOS:
CHAOS:
IONIA:
SCIENTISTS: Who & What

44. 2 C om p e ting Id e as
• CHAOS:
– Idea that the World was totally
unknowable and unpredictable.
– “ RANDOM” - Religion
• COSMOS:
– Idea that the World was Ordered and
predictable
– “ ORDER” – Science
– “TO KNOW”

45. IONIA
•IONIA: loose collection of city-states scattered
around the Aegean Sea,
•Birthplace of SCIENCE!
•Chased there, NOT an easy place to live.
•To stay alive, people had to experiment & invent
•Merchants and Tradesmen experimented and
thought of NEW THINGS!

47. THALES of Miletus: FIRST true scientist
-Well traveled Greek-
-Explained the world WITHOUT gods
-Earth Made from Piled Mud by water
Thales ANAXAMANDER: First recorded
ever to DO an
experiment
measured time
THEODORUS: Conceived of
Architect, artist, Inventor EVOLUTION
Anaxamander
ore smelting & casting.
water level,
a carpenter's square,
lock and key
turning lathe.

48. EMPEDOCLES: Conceived the idea of invisible
matter, air, water pressure
DEMOCRITUS: First to
Describe the indivisible ATOM
Conceived of planets like ours in
the sky
Figured galaxies & Milky Way
Democritus as many small stars

49. SILENT QUESTION
• COMPARE & CONTRAST:
ROTATION to REVOLUTION
ROTATIO- VOLVERE-
Rolling To Turn
Around
Rotate: to spin on (something else)
one’s own
Axis
Revolve: turn in orbit around

50. SCIENTIFIC METHOD:
• Used in ALL Sciences
• Used to Solve Problems
&Answer Questions
• Hypotheses are QUESTIONED!!!!!
AGAINST the scientific
method:
Philosophers, who would T H I N K
about a problem until they decided
what the most Logical explanation
for something was, and assumed
they were right-
still, it WAS an attempt at Cosmos

51. Cosmology pt 2
• How is the Universe set
up?
• 2 competing ideas:
•GEOCENTRIC
– Earth is the center of the Universe
– Reasoning:
• Everything in the sky Appears to be
revolving around the Earth from
East to West.

52. • Reasoning cont... Geocentric
–The Faster an Universe
object moved,
the closer to
earth it must
be.
–“Planetia” have
their own
spheres of
movement.
–Stars are in
fixed positions
on the “CELESTIAL
SPHERE”

53. • Reasoning cont... Geocentric
Universe
• Question?
• D o all the ob jects /
sp heres revolve
around Earth?
Or
• D oes Earth Rotate in
the m id d le of the
sp heres?

54. • Reasoning cont... Geocentric Universe
–Aristotle liked this theory.
–Problem:
–Unexplained forces?
–Why are some stars
brighter / bigger?
–Why all planets/Sun
/Moon on the same plane?
–ECLIPTIC – Line showng the path of
the sun in the sky.
–Retrograde motion...

55. Heliocentric
Universe
• Aist r ofSa
r achus mos-
– Used Eaost
r t henes’ E rh Cir
at cumfer a t Sha dur L recl t
ence nd he dow ing una ipses o
det mine M Dia er
er oon’s met .
– Suggest t tt SUNis t cent ofr ol ionaymot
ed ha he he er ev ut r ion.
– Used M a E rh sizes t E imae Sun Dist nce a Size oft Sun.
oon nd at o st t a nd he
– Ws W YOF .
a A F

57. Locating Stars pt1
• “Celestial Sphere”
• An imaginary globe around the Earth.
• Used to determine star locations
• First “Model” used to
understand the universe
• We NOW understand that
they are different distances
from us, but still works for
our reference.
• Remains VIRTUALLY unchanged

58. Planispher
e
• A tool for showing
what stars will be in
the sky on any
particular day &
time.

59. Using the Planisphere
• Assumes a viewing location of 40° North
– We are close enough (42°)
• Must be held above the head and looked at
from below.
– (Notice East and west)

60. LOCAL REFERENCE MEASURES
• A LTITUDE • A ZIMUTH
– Angular inclination above – Angular distance from North
the Horizon – Measured clockwise
• HORIZON = 0 ° • N=0°
• ZE NITH = 90 ° • E =90°
• S =180°
• W=270°

61. LOOKING AT PLANETS
• C OMPA RE D TO THE
C E LE S TIA L S PHE RE
• We mus t be able to
imagine both
GE OC E NTRIC A LLY &
HE LIOC E NTRIC A LLY

62. Picture 4
S
DRAW UNIVERSE
HELIOCENTRICALLY

63. Celestial Coordinates
• DE C LINA TION • RIGHT
– Angular Difference from A S C E NS ION
Celestial Equator
– Measured in HOURS and
• E quator = 0 ° minutes
• North S tar = 90 ° • C eles tial
• Like Celestial LATITUDE
Meridian=0hr
• Like Celestial Longitude

65. HOMEWORK:
–DRAW heliocentric and
Geocentric Universe According to
this night sky

66. RIGHT ASCENSION /
DECLINATION
PRACTICE

67. E quat Zodia
Polar
orial cal
Name R.A. Dec Name R.A. Dec Name R.A. Dec

68. Pick one of Each.
Equatorial ZODIACAL CIRCUMPOLAR
• Orion • Virgo
• Cetus • Leo • Draco
• Canis Major • Cancer • Ursa Major
• Gemini
• Hydra • Ursa Minor
• Taurus
• Aquila • Aries • Perseus
• Cygnus • Pisces
• Pegasus • Cassiopeia
• Aquarius
• Andromeda • Capricornus • Cepheus
• Lepus • Sagitarius • Cameleopardu
• Hercules • Scorpius
s
• Libra

69. Greek
Alphabet
OR
use
assigned
name

70. HOM W K
E OR
• R e a d in g C H 1
S e c t io n 1
• G r a b R e v ie w
S he e t
• C o o r d in a t e
A s s ig n m e n t :

71. HIPPARCHUS
• FIRST STAR CATALOGUE
• 1025 STARS

72. Retrograde Motion
• “Backward”
“Walk”
• Each planet
moves compared
to the Celestial
Sphere.
– From East to
West
• Occasionally, the
planet will stop,
move West to

73. FIRST 15 - 25 Min.
• Discuss Material Coverage
– Preview, 2-1, 1-1, 2-2, 1-2, 1-3, 1-4
• FINISH CONSTELLATION
COORDINATES
• ANSWER RETROGRADE LAB
QUESTIONS

74. Ptolemy’s Universe
• Alexandrian Greek
• To explain retrograde
motion, suggested
EPICYCLES
– Each planet orbits
around an empty point
on its sphere.
– EARTH is just OFF
center
• Better at predicting
planet locations
• For Astrology

75. Problem with Ptolemaic Universe
• It v io la t e s a k e y
s c ie n t if ic p r in c ip le :
• O c c a m 's r a z o r:
a k a l e x p a r s imo n ia e
– “ O t h e r t h in g s b e in g
e q u a l, a s im p le r
e x p la n a t io n is b e t t e r
t h a n a m o r e c o m p le x
o ne .”

76. Heliocentric explanation of Retrograde
• E a r t h R e v o lv e s
a round S un FAS T
• M a r s R e v o lv e s
a round S un S LO W
• W h e n o n p la n e t
“ L A P S ” a no the r,
o u r p e r s p e c t iv e
s h if t s .

77. Heliocentric explanation of nightly Star Shift
• Th e L O C A L s ta r s
lo c a t io n s c h a n g e a t
a d if f e r e n t r a t e t h a t
the L O C A L s un
lo c a t io n .
• Th e S U N r e tu r n s to
a s p o t in t h e s k y
– E ve ry 2 4 ho urs
• A S TA R r e tu r n s to a

78. Re t u r n t o Ge o v H e l
io

79. Rotation v. Revolution
• T h in k B IG
• ? H o w lo n g f o r E a r t h t o
R E VO L VE o nc e ?
– 3 6 5 . 2 5 D A YS
• ? H o w M a n y D e g r e e s a lo n g
t h e o r b it d o e s E a r t h s h if t
e a c h D a y?
– 3 6 0 ° ÷ 3 6 5 d a y s ≈ 1° / D a y
• ? H o w lo n g f o r E a r t h t o
R O TA TE o n c e ?
– NOT 2 4 HOUR S
– 2 4 hr = NO O N to N O O N .
– B U T, w e h a ve s h i f t e d 1° o n
t h e o r b it .
– 2 4 hours ÷ 3 6 1° ≈

80. SID ERIAL vs SYN O D IC
D AY
• S I D E RI AL D AY=
– A m o u n t o f t im e it
ta k e s fo r a s ta r to
r e t u r n t o a lo c a l
p o in t .
– 2 3 H r , 5 6 m in ,
4sec
• S YN O D I C D AY=
– A m o u n t o f t im e it

81. Another thing Rotation Explains...
• A ll r o t a t in g o b je c t s
w o b b le
• P R E C E S S IO N
• A s it p r e c e s s e s , t h e
p o in t o n t h e
c e le s t ia l s p h e r e t h e
p o le p o in t s t o c h a n g e s .
• N o rth S ta r c ha ng e s
v e r y s lo w ly

82. Heliocentrism
• WHY It NEVER TOOK OFF:
–Went against THEOLOGY
–Most scientists agreed that stars
would be at different distances
from Earth.
–If the Earth changed Position in
relation to those stars, they
SHOULD appear to change
location relative to each other.
–PARALLAX

84. PARALLAX
• When observed from 2 different
locations, a near obj shifts greater
ect
angularly than a distant one.
• Using trigonometry, we can find the
distance to that object.

85. Using Parallax to find distance
θ
α
α
θ
BASELINE (b): Distance between 2 observation points
θ: Change in angle to apparent location of Star in Question
α: Other angle
d: Distance to the Star in Question

86. F in d in g
D is t a n c e
U s in g
P a r a lla x
d= .5b
tan α

87. NEED:
• NOTEBOOKS
• +
• 1 lined paper to hand in

88. Misperception and Misconceptions
• People have told you wrong information
about the universe.
• You have made stuff up to understand the
universe.
• UNLEARNING is the hardest type of
learning.

89. 3 QUESTIONS?
• WHAT CAUSES THE SEASONS?
• WHAT CAUSES THE PHASES OF THE
MOON?
• WHY IS THE SKY BLUE?

90. THE SEASONS:
• Result from a confluence of events / Factors
–
Earth’s Rotation is Tilted23.5º
to the plane of the ecliptic (Earth’s Orbital Plane)
•SO WHAT?!?!?!?!?!?
– As Earth Revolves around the Sun, The poles are
at different angles to the Solar rays
– As the Earth Rotates at different points along it’s
orbit, different parts of the Earth are exposed to
sunlight for different periods of time.

91. WHEN LOOKED AT FROM ABOVE ( NORTH POLE)
EARTH ROTATES COUNTERCLOCKWISE
EARTH REVOLVES COUNTERCLOCKWISE

92. Seasons
• “SUMMER”=
– Period of the year where the sun is most directly
overhead
• “WINTER”=
– Period of the year where sun is least overhead.
• Technically starts on the day where sun is to it’s TROPIC
LINE
– Heating up or cooling down happens slowly, so
Temperature extreme days = 2 months later
• “SPRING” & “FALL”=
– Period of time where the sun is Overhead at the

93. SUNoverhead the sun is, the
• The more directly
ANGLE
Greater the intensity energy is transferred to the
Earth.
LOW SUN ANGLE = WEAK HIGH SUN ANGLE =
HEATING STRONG HEATING

94. SUN OVERHEAD?
• DEC 21 -
– TROPIC OF CAPRICORN – 23.5º S
• MAR 21 -
– EQUATOR
• JUN 21 -
– TROPIC OF CANCER – 23.5º N
• SEPT 21 -
– EQUATOR
• KALAMAZOO:
–42.3º N
– To find our NOON SUN ANGLE
– Find How Far away are we from Overhead Sun

95. HOMEWORK
•1-18
•SKIP 7&11

96. DAY LENGTH

97. DAY LENGTH
• The Hemisphere inclined TOWARD the sun receives more
hours of DAYLIGHT.
• Greater Time lit=More time to convert sunlight to heat.
• ARCTIC / ANTARCTIC CIRCLES:
–66.5° N &S
– Above which, at LEAST ONE DAY / YEAR, the sun will not
set, & 6 months later, will not rise
– “Land of the Midnight Sun”

98. DAY LENGTH
• SOLSTICES:
– Greatest / Least amount of Solar Time
– Sun rises the Farthest North / South
• EQUINOXES:
– Equal Light & Dark: 12 & 12
– Sun Rises Due East, Sets Due West

102. • Where is the sun overhead?
• Where is observer?
• Find the difference.
• 90-difference= noon sun angle

103. • Video – Seasons / Sun Angle
• FINISH SEASONS LAB PACK
– (GRAPH)

104. PHASES OF THE MOON

105. The Cause:
• Earth Rotates 361º/ 24 hours
(Counterclockwise)
• Moon Revolves around Earth / 29.5 days
(Counterclockwise)
• NOTICE:
– Moon Rotation
• 360º Rotation / 1 Revolution
• Moon ALWAYS has the same side facing Earth.

106. VISIBLE MOON
• ONLY ½ of the moon
will be lit at any 1 time.
• Depending on WHERE
the moon is in relation
to the sun, we see
different Parts.

107. WHERE ARE THE PHASES?
• NEW MOON:
• WHAT DO WE SEE?
– Dark side of the moon
• WHERE IS THE MOON COMPARED TO
SUN?
– +5º to -5º Declination from the ecliptic
– If it was ON the ecliptic=
• eCLIPSE

108. WHERE ARE THE PHASES?
• WAXING CRESCENT:
• WHAT DO WE SEE?
– RIGHT edge of the moon lit
• WHERE IS THE MOON COMPARED TO
SUN?
– ≈45º to the LEFT of the moon

109. WHERE ARE THE PHASES?
• FIRST QUARTER:
• WHAT DO WE SEE?
– Right HALF of the moon lit
– “quarter”??? Because we see ¼ of the moon
• WHERE IS THE MOON COMPARED TO
SUN?
– 90º to the LEFT of the moon

110. WHERE ARE THE PHASES?
• WAXING GIBBOUS:
• WHAT DO WE SEE?
– All but the left edge of the moon lit
• WHERE IS THE MOON COMPARED TO
SUN?
– ≈135º to the LEFT of the moon

111. WHERE ARE THE PHASES?
• FULL MOON:
• WHAT DO WE SEE?
– A full side of the moon, all that is lit
– As much of the moon we can see: ½
• WHERE IS THE MOON COMPARED TO
SUN?
– 180º , in opposition with the sun

112. WHERE ARE THE PHASES?
• WANING GIBBOUS:
• WHAT DO WE SEE?
– All but the RIGHT edge of the moon lit
• WHERE IS THE MOON COMPARED TO
SUN?
– ≈135º to the RIGHT of the moon

113. WHERE ARE THE PHASES?
• THIRD QUARTER:
• WHAT DO WE SEE?
– Left HALF of the moon lit
– “quarter”??? Because we see ¼ of the moon
• WHERE IS THE MOON COMPARED TO
SUN?
– 90º to the RIGHT of the moon

114. WHERE ARE THE PHASES?
• WANING CRESCENT:
• WHAT DO WE SEE?
– LEFT edge of the moon lit
• WHERE IS THE MOON COMPARED TO
SUN?
– ≈45º to the RIGHT of the moon

115. ECLIPSES
• Solar
– Moon Blocks Sun’s visible disk
– Can only happen during NEW MOON
– Still Visible:
• Sun’s CORONA
– Solar ATMOSPHERE
– Very Brief
• Moon’s shadow is small
• Earth Rotates Quickly

116. • Partial
– Some sun is still visible
– (in the Penumbra)
• Totality
– No part of Solar Disk is visible
– (in the Umbra)
• Annular
– Only the outer Ring of Sun is visible.

117. eclipses
• Lunar
– Earth Blocks Sunlight from reaching the Moon
– Can only happen during a FULL MOON
– Still Visible “Blood Moon”
• Sunlight passes through our atmosphere
• Blue light is scattered
• Reddish light passes through to Moon
– Lasts several Minutes
• Earth’s shadow is BIG compared to moon

118. Why Eclipses don’t happen all the time
• Moon’s Orbit is tilted 5 degrees to the Ecliptic
• The “NODE” need to be hitting a FULL or
NEW to have a chance to Eclipse
• 2x / year

119. Picture 5

120. LAST 30 min
• FINISH LAB PACK(s)
• PHASES
• SEASONS
• PARALLAX
• RETROGRADE
• RA / DEC

121. PLAN FOR THE DAY
• C H E C K / D IS C U S S P R A C T IC E
C O M P U T A T IO N
• - R E A D IN G A S S IG N M E N T
C O R R E C T IV E S
–Grade Your Homework for
CORRECTNESS
• (Every wrong answer =-1 to score.)
–CORRECT ERRORS

122. Universe
• Made of MATTER & ENERGY
• MATTER:
– Atoms of Elements made of
• Protons, Neutrons and Electrons.
• ENERGY:
– 4 known forces
• Electromagnetism
• Gravity
• Weak Nuclear Force
• Strong Nuclear Force

123. Unknown Universe
• “Dark Matter”
– “Invisible” “Sources of gravity”
– Possible Neutrino source
• “Big Bang”
– Concept that the Universe started as one
small point of reality, and is expanding.
– Expansion is speeding up
• “Dark Energy”
– Antigravity pushing galaxies apart