lOMoARcP SD| 69 29 841 0
Astronomy 101 Notes
, lOMoARcP SD| 69 29 841 0
Astronomy 101
Week 1
● Astronomy is the first and oldest science (arguably)Vast cultural & historical
interpretations
○ Some cultures used written records (Mayan codices, Korean &
Chinese court records), while others used oral tradition, art,
and/or architecture
● Ex 1 The Pleiades (equatorial star grouping, visible from north to south)
○ Interpreted differently across all cultures ● Ex 2 The Great Bear
○ Both Native Americans and Greeks share the connection of this constellation
through the “bear” the name in greek roughly translates to bear ● Ex 3 Polaris
○ Directly above the North Pole
■ Doesn’t move in the night sky
○ The Phoenicians used this to navigate, is sung about by native americans
● Many interpretations and findings have been lost to colonialism
Stonehenge
● Many stone circles in the UK alone not just the Stonehenge
● You can find various arrays of stones all over the world
● Huge stones, shaped, and brought across the country indicating a large significance to
the site
● Construction took many centuries
● Not connected to the druids
Giza Pyramids
● Evidence of development over 2000 years
● Were actually not built by slaves
● From the queen’s chamber, there are alignments to Sirius and Kochab
● From the kings, Orion’s Belt and Alpha Draco
Petroglyphs
● Modest representations
● E.g. Emu in Ku rin gai National Park
Why Study Astronomy?
1. Tracking the passage of time
a. Sundial
b. Moon phases
2
, lOMoARcP SD| 69 29 841 0
c. Seasonal change
d. One full moon to the next is aprox. 29.5 days (7yrs out of every 19) about 13
full moons in a year
e. Commemorated by Native Americans’ “Turtle’s Back”, the 13 panels on their
shell help tell Natives the time of year and what to do
f. 88 official constellations
g. You can use the constellations or rather which ones you can see to tell what
time of the year it is (the zodiac)
h. Northern constellations are different
i. Since they lie above, its view is not restricted by the Sun
2. Navigation
3. Religious Significance
a. Constant & Unchanging stars were looked at like the heavens
4. Others include
a. Search for Extraterrestrial Intelligence SETI
b. Pursuit of knowledge
c. Pushing the limits of physics
Ideals of a Science
● In a “Western Paradigm” science should be:
○ Testable, Rational, Ready to Challenge authority, Seeks cause ‘n’ effect,
Quantitative, Productive, Minimalist in its assumptions
● Only one apparatus (“the universe”)
● No experimentation
● Requires large extrapolations and other fundamental assumptions about physical laws
● Note that big numbers are NOT a problem they appear all the time in our lives
○ Use sensible units to deal with this
Interpolation vs Extrapolation
● Interpolation: Making an estimation in between two points/observation
● Extrapolation: A riskier guess beyond the point of observation
We assume that the nature of light and matter, and the fundamental laws of physics are the
same from place to place within the universe as time passes indefinitely
The sizes of limbs correspond to the amount of force needed to counteract Earth's gravity.
Larger animals like elephants need thicker, stronger legs to hold themselves up, compared to
ants with twig-like limbs.
Self-Gravity: Influence of parts of an object by the rest of the same object.
- No practicality for bodies of little mass
, lOMoARcP SD| 69 29 841 0
- Tall structures are difficult to build because of this effect. The structures that lead
higher into the sky situates pressure on the lower areas of said structure. Basically, the
taller the structure is, the harder it is to keep the structure upright without deformities.
- Larger celestial objects are more round in shape, smaller objects are less likely to be
round
- Asteroids look like poop because it doesn't have enough force to pull all parts of itself
evenly toward the center.
- Mountains
- Mountains on mars, and smaller astronomical bodies, can be larger than that of larger
ones, because of the effect of self gravity.
- Smaller bodies ‘tug’ at other parts of itself less, enabling the ability for larger
structures to exist naturally
- Thanks to self gravity, big things remain round
- Tend to retain their interior heat for longer times
- Earth molten core vs moon solid core Gravitational vs ElectroMagnetic force
- Gravity is the weakest of the 4 fundamental forces
- Electromagnetic wins in smaller scales
- Gravity wins in much larger scales because the forces of gravity are cumulative.
Electromagnetism has positive and negative charges. Mass by contrast has no
negative counterpart.
Losing Internal Heat
- Conduction, Convection, and Radiation are ways of transferring heat - Every
object has an inside and an outside
- Size matters in heat loss; larger objects have a harder time losing energy (interior
heat)
- Shape matters; larger surface area loses heat energy easily
Why are stars born hot
- Gravity and Conservation of Energy
- Particles attract each other forming a large gaseous body .
- As atoms get closer together they speed up and gain temperature
Week 1 Reading
North America: Charting Celestial Symmetry
● Native Americans had devised a variety of unwritten forms of expression about
the sky well before Columbus
● How did NA’s first astronomers interpret the sky?
○ Calendar sticks and star maps made on hides naming the constellations
4
Astronomy 101 Notes
, lOMoARcP SD| 69 29 841 0
Astronomy 101
Week 1
● Astronomy is the first and oldest science (arguably)Vast cultural & historical
interpretations
○ Some cultures used written records (Mayan codices, Korean &
Chinese court records), while others used oral tradition, art,
and/or architecture
● Ex 1 The Pleiades (equatorial star grouping, visible from north to south)
○ Interpreted differently across all cultures ● Ex 2 The Great Bear
○ Both Native Americans and Greeks share the connection of this constellation
through the “bear” the name in greek roughly translates to bear ● Ex 3 Polaris
○ Directly above the North Pole
■ Doesn’t move in the night sky
○ The Phoenicians used this to navigate, is sung about by native americans
● Many interpretations and findings have been lost to colonialism
Stonehenge
● Many stone circles in the UK alone not just the Stonehenge
● You can find various arrays of stones all over the world
● Huge stones, shaped, and brought across the country indicating a large significance to
the site
● Construction took many centuries
● Not connected to the druids
Giza Pyramids
● Evidence of development over 2000 years
● Were actually not built by slaves
● From the queen’s chamber, there are alignments to Sirius and Kochab
● From the kings, Orion’s Belt and Alpha Draco
Petroglyphs
● Modest representations
● E.g. Emu in Ku rin gai National Park
Why Study Astronomy?
1. Tracking the passage of time
a. Sundial
b. Moon phases
2
, lOMoARcP SD| 69 29 841 0
c. Seasonal change
d. One full moon to the next is aprox. 29.5 days (7yrs out of every 19) about 13
full moons in a year
e. Commemorated by Native Americans’ “Turtle’s Back”, the 13 panels on their
shell help tell Natives the time of year and what to do
f. 88 official constellations
g. You can use the constellations or rather which ones you can see to tell what
time of the year it is (the zodiac)
h. Northern constellations are different
i. Since they lie above, its view is not restricted by the Sun
2. Navigation
3. Religious Significance
a. Constant & Unchanging stars were looked at like the heavens
4. Others include
a. Search for Extraterrestrial Intelligence SETI
b. Pursuit of knowledge
c. Pushing the limits of physics
Ideals of a Science
● In a “Western Paradigm” science should be:
○ Testable, Rational, Ready to Challenge authority, Seeks cause ‘n’ effect,
Quantitative, Productive, Minimalist in its assumptions
● Only one apparatus (“the universe”)
● No experimentation
● Requires large extrapolations and other fundamental assumptions about physical laws
● Note that big numbers are NOT a problem they appear all the time in our lives
○ Use sensible units to deal with this
Interpolation vs Extrapolation
● Interpolation: Making an estimation in between two points/observation
● Extrapolation: A riskier guess beyond the point of observation
We assume that the nature of light and matter, and the fundamental laws of physics are the
same from place to place within the universe as time passes indefinitely
The sizes of limbs correspond to the amount of force needed to counteract Earth's gravity.
Larger animals like elephants need thicker, stronger legs to hold themselves up, compared to
ants with twig-like limbs.
Self-Gravity: Influence of parts of an object by the rest of the same object.
- No practicality for bodies of little mass
, lOMoARcP SD| 69 29 841 0
- Tall structures are difficult to build because of this effect. The structures that lead
higher into the sky situates pressure on the lower areas of said structure. Basically, the
taller the structure is, the harder it is to keep the structure upright without deformities.
- Larger celestial objects are more round in shape, smaller objects are less likely to be
round
- Asteroids look like poop because it doesn't have enough force to pull all parts of itself
evenly toward the center.
- Mountains
- Mountains on mars, and smaller astronomical bodies, can be larger than that of larger
ones, because of the effect of self gravity.
- Smaller bodies ‘tug’ at other parts of itself less, enabling the ability for larger
structures to exist naturally
- Thanks to self gravity, big things remain round
- Tend to retain their interior heat for longer times
- Earth molten core vs moon solid core Gravitational vs ElectroMagnetic force
- Gravity is the weakest of the 4 fundamental forces
- Electromagnetic wins in smaller scales
- Gravity wins in much larger scales because the forces of gravity are cumulative.
Electromagnetism has positive and negative charges. Mass by contrast has no
negative counterpart.
Losing Internal Heat
- Conduction, Convection, and Radiation are ways of transferring heat - Every
object has an inside and an outside
- Size matters in heat loss; larger objects have a harder time losing energy (interior
heat)
- Shape matters; larger surface area loses heat energy easily
Why are stars born hot
- Gravity and Conservation of Energy
- Particles attract each other forming a large gaseous body .
- As atoms get closer together they speed up and gain temperature
Week 1 Reading
North America: Charting Celestial Symmetry
● Native Americans had devised a variety of unwritten forms of expression about
the sky well before Columbus
● How did NA’s first astronomers interpret the sky?
○ Calendar sticks and star maps made on hides naming the constellations
4
