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ASTRONOMY AND ASTROPHYSICS: Activity & Lab Book
by Dr. Sarah Salviander
Published by Castalia House
Kouvola, Finland
www.castaliahouse.com
This book or parts thereof may not be reproduced in any form, stored in a retrieval system, or transmitted in any form by any
means—electronic, mechanical, photocopy, recording, or otherwise—without prior written permission of the publisher, except
as provided by Finnish copyright law.
Copyright ©2014 by Dr. Sarah Salviander.
All rights reserved
Data from SOHO, the Solar and Helioispheric Observatory, is courtesy of SOHO consortium. SOHO is a project of international
cooperation between ESA and NASA. http://soho.nascom.nasa.gov.
Planetary images are courtesy of the Planets app from QContinuum Freeware. http://qcontinuum.org/.
Sloan Digital Sky Survey (SDSS) data and images are courtesy of Sloan Digital Sky Survey (SDSS) Collaboration,
http://www.sdss3.org.
Screen capture from the Sky & Telescope Jupiter Moons interactive observing tool ©Sky & Telescope. All rights reserved. Used
with permission
ISBN 978-952-7065-31-0
Version 001
PERMISSIONS
Castalia House is committed to making high-quality curricula affordable for everyone. Therefore:
1. Homeschooling parents are permitted to use a single purchased copy of the Instructor’s Guide, the Activity & Lab Book,
and the Biblical Supplement for their family. A copy of the Exam Book must be purchased for each individual child.
2. Homeschool cooperatives are permitted to use a single purchased copy of the Instructor’s Guide and the Biblical Supplement for their meetings. One copy of the Activity & Lab Book must be purchased for each family participating and a copy
of the Exam Book must be purchased for each individual child.
3. Public and Private Schools are permitted to use a single purchased copy of the Instructor’s Guide and the Biblical
Supplement for each teacher. One copy of the Activity & Lab Book and one copy of the Exam Book must be purchased for
every individual student in the class.
2
Contents
1
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4
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12
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2
Chapter 2: Method for Finding Scientific Truth
2.1 Angles and Distance (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Plato and Aristotle (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
20
29
3
Chapter 3: Astronomy Without a Telescope
3.1 Planisphere (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Motion of the Sky (Evening/Outdoor Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
31
32
4
Chapter 4: History and Philosophy of Western Astronomy
4.1 Galileo and the Inquisition (Activity) . . . . . . . . . . . . . . . .
4.2 Drawing Ellipses (Activity) . . . . . . . . . . . . . . . . . . . . . .
4.3 Ancient Astronomy and Constellations (Evening/Outdoor Lab)
4.4 Kepler’s Third Law (Activity) . . . . . . . . . . . . . . . . . . . . .
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43
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50
Chapter 5: Newton’s Law of Gravity
5.1 Understanding the Gravitational Constant . . .
5.2 Acceleration and Mass (Activity) . . . . . . . . .
5.3 Orbital Formulas (Activity) . . . . . . . . . . . . .
5.4 Measuring Earth’s Gravity (Lab) . . . . . . . . . .
5.5 The Mass of Jupiter (Lab) . . . . . . . . . . . . . .
5.6 The Fount of Genius: Great Questions (Activity)
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52
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6
Chapter 6: Einstein’s Relativity
6.1 Special Relativity (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2 Lorentz-Fitzgerald Contraction Formula (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
77
78
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7
Chapter 7: Electromagnetic Radiation (Light)
7.1 Spectroscopy (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
80
81
8
Chapter 8: Telescopes
8.1 Getting to Know Your Telescope (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
90
91
9
Chapter 9: Planetary Science
95
9.1 Observing the Planets (Evening/Outdoor Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
9.2 The Moon (Evening/Outdoor Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
5
Chapter 1: Astronomy as a Science and a Sense of Scale
1.1 The Universe According to You, Part I (Activity) . . .
1.2 A Sense of Scale, Part I (Activity) . . . . . . . . . . . .
1.3 A Sense of Scale, Part II (Activity) . . . . . . . . . . .
1.4 Distance Formula (Activity) . . . . . . . . . . . . . .
1.5 Metric System (Activity) . . . . . . . . . . . . . . . .
1.6 A Sense of Time, Part I (Activity) . . . . . . . . . . . .
1.7 A Sense of Time, Part II (Activity) . . . . . . . . . . .
1.8 Astrology (Lab) . . . . . . . . . . . . . . . . . . . . . .
1.9 Good Questions (Activity) . . . . . . . . . . . . . . .
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10 Chapter 10: Solar System Fluff
113
10.1 Radioactive Dating Formula (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
11 Chapter 11: Stellar Properties
11.1 Trigonometric Parallax Formulae (Activity) . . . . . .
11.2 Trigonometric Parallax Formulae (Advanced Activity)
11.3 Inverse Square Law (Activity) . . . . . . . . . . . . . .
11.4 The Doppler Effect I: Motions of Stars (Lab) . . . . . .
11.5 Binary Stars (Evening/Outdoor Lab) . . . . . . . . . .
3
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115
116
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125
136
12 Chapter 12: The Sun and Stellar Structure
143
12.1 Solar Activity (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
13 Chapter 13: Lives and Deaths of Stars
151
13.1 The Hertzsprung - Russell Diagram (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
13.2 Black Hole Scale Model I: Stellar Remnants (Activity) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
14 Chapter 14: The Interstellar Medium and the Milky Way
164
14.1 Clusters and Nebulae (Evening/Outdoor Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
14.2 Variable Stars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
15 Chapter 15: Other Galaxies and Active Galaxies
15.1 Galaxy Classification (Lab) . . . . . . . . . . . . . . . . . . . . . .
15.2 The Doppler Effect II: The Hubble Constant (Lab) . . . . . . . .
15.3 Black Hole Scale Model II: Supermassive Black Holes (Activity)
15.4 The Doppler Effect III: Supermassive Black Holes (Lab) . . . . .
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180
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16 Chapter 16: Cosmology
211
16.1 A Rubber Band Universe (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
16.2 Dark Matter (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
17 Chapter 17: Life Beyond the Earth
229
17.1 An Interstellar Message (Lab) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
18 Chapter 18: String Theory and the Multiverse
18.1 The Elegant Universe—Review Questions . . . .
18.2 The Fabric of the Cosmos—Review Questions .
18.3 Strings and Stories (Activity) . . . . . . . . . . . .
18.4 The Universe According to You, Part II (Activity)
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234
235
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240
The cover photo shows the spiral galaxy M74 taken by the Hubble Space Telescope. Credit: NASA, ESA, and the Hubble Heritage
(STScI/AURA)-ESA/Hubble Collaboration.
4
1 Chapter 1: Astronomy as a Science and a Sense of Scale
5
1.1 The Universe According to You, Part I (Activity)
Date:
Just about every person has a concept of the universe—what he or she imagines it looks like, on small scales and
large—even in the absence of any formal knowledge of the universe. In this first activity of the course, before you
begin your formal study of the universe and its contents, you will draw your personal concept of the universe on the
scale of the solar system and on the scale of the very large. You will also write a brief statement explaining your view
of the origin of the universe. You will repeat this activity on the last day of the course, after you’ve learned a great
deal about the universe, and compare your two concepts.
Equipment
• Two blank sheets of 8.5” x 11” paper
• Pencil and eraser
• Colored pencils (optional)
Your concept of the solar system
On the first sheet of paper, draw what you think the solar system looks like. You may construct the drawing any way
you wish, as long as it conveys how you think the solar system is constructed. Include as much detail as possible. If
you like to use color, by all means do so, but it is not required.
Your concept of the large-scale universe
On the second sheet of paper, draw what you think the universe looks like on a very large scale—as large as you
can imagine. You may construct the drawing any way you wish, as long as it conveys how you think the large-scale
universe is constructed. Again, make it as detailed as possible; and, if you like to use color, do so, but it is not
required.
Origin of the universe
On the back of the large-scale drawing, write a short paragraph (2-3 sentences) explaining how you think the
universe came into being.
Sign your name and the date to both of the concept drawings and save them for the end of the course.
6
1.2 A Sense of Scale, Part I (Activity)
Date:
The following exercise will help you comprehend the size and makeup of our solar system and the distance to the
nearest star. It will also give you practice using the metric system and scale models.
Recreate the Scaled Model of the Solar System table from the textbook using a marble to represent the Sun. In this
activity you will only calculate the scale distances from the Sun, not the scale size of the objects.
Real diameter of the Sun (km) / Diameter of the marble (m)
1,392,000 /
=
Scale factor of the model
(quantity all other numbers
will be divided by)
=
A New Scaled Model of the Solar System
Object
Real distance from the Sun
(million km)
Scaled distance
(m)
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Oort Cloud
Proxima Centauri
Optional: If possible, take the marble and some other kinds of markers to a field and attempt to create a rough scale
model of the solar system. Will you be able to include the Oort Cloud in this rough scale model? Why or why not?
You won’t be able to include Proxima Centauri in this model, so to get a sense of where it would be in the model,
look on a map to find which city or town is approximately Proxima Centauri’s scaled distance from your home.
7
1.3 A Sense of Scale, Part II (Activity)
Date:
This exercise will help you comprehend the distances between galaxies and compare the makeup of galaxy groups
to the structure of our solar system.
1. You will make a very simple scale drawing of the spatial relationship between our galaxy and its nearest
neighbors. Draw a circle 1 cm in diameter in the corner of a normal sheet of paper. This will represent the
Milky Way Galaxy. That means that the scale of this scale drawing will be:
1 cm = 100,000 light-years
Use this scale to position the nearest galaxy, Canis Major Dwarf (described in the textbook as the small
irregularly-shaped one), the Large Magellanic Cloud, the Small Magellanic Cloud, and the Andromeda Galaxy
on the sheet of paper. You will have to adjust the textbook’s scale to the new scale indicated above. It isn’t
necessary to get the relative sizes of these galaxies, just their distances from the Milky Way Galaxy.
A New Scaled Model of the Local Universe
Galaxy
Textbook scale distance
from the Milky Way
Canis Major Dwarf
13 cm
Large Magellanic Cloud
30 cm
Small Magellanic Cloud
35 cm
Andromeda
New scale distance
from the Milky Way
4.8 m = 480 cm
2. Compare this scale model with the scale model of the Solar System from Part I. What do you notice about the
relative size of the space between objects in one model compared with the other?
8
1.4 Distance Formula (Activity)
Date:
Don’t be afraid of algebra
A lot of people struggle with algebra and feel that they can never understand it. But, they can. The biggest problem
with algebra and math in general is that it is one of the worst taught subjects, and this failure of the school system
begins in elementary school and usually continues all the way through high school.
Students are usually shown what to do (do this step, then this step, and finally this step), but they are seldom helped
to understand why things are done the way they are. Math as just a set of rules to be remembered is boring and
confusing. Math should be taught as a problem-solving language. Let us show you how it works and then we’ll apply
it to your astronomy assignments.
Suppose that you want to solve an everyday problem such as how to replace the carpet in your bedroom or build a
rectangular platform for a skateboard ramp. It would help to know how many square feet of material you need so
you can estimate the cost. The problem will be written in English first, then in math, and then we’ll compare the two
different ways.
In English:
The area of a rectangle is equal to the length of the rectangle multiplied by the width of the rectangle.
Let’s focus on the key words of the solution:
The area of a rectangle is equal to the length of the rectangle multiplied by the width of the rectangle.
The words we left in black are helpful to understand the problem, but they aren’t really necessary. Let’s take the
necessary words that were underlined and make a simpler statement with them:
Area is equal to length multiplied by width.
Now let’s make the statement even simpler by using initials for some of the words and basic math symbols for others:
Area
is equal to
A
=
length
multiplied by
L
×
width
W
A=L×W
This shows the real reason for algebra. When the solution to the area problem is written in English, it takes over 80
symbols (letters and punctuation). The same solution written in the language of math takes only 5 symbols. The
math way takes far less work and makes the steps involved in the solution so much easier to understand.
A = L × W is an equation (it has an equal sign in it). But it isn’t just an ordinary equation like the ones teachers often
use to try to teach algebra skills and concepts (such as X + Y = 2) it is a special kind of equation that is actually used
to solve real-life problems. We call these special equations formulas.
Think for a minute about what a formula does for you: A = L × W
First, the A to the left of the equal sign tells you what the formula is set up to do, find the area. You just have to
remember that this particular formula is designed to find the area of a rectangle. Other formulas start with A but
they are set up to find the areas of other shapes. For example A = 12 b × h is used to find the area of a triangle. The
nice thing about the Internet age is that you really don’t have to remember formulas anymore because you can find
any formula in less than a minute by searching for it online. But, you do have to know how to use them once you
find them.
Next, if you look to the right of the equal sign, the formula tells you exactly what quantities you need to know in
order to find the desired answer. In this case you need to know L (the length of the rectangle) and W (the width of
9
the rectangle). Sometimes someone will be able to tell you what they are, but most times in real life you will have to
measure them yourself.
Finally, once you have numbers for L and W, the formula tells you exactly what to do with them. In this case the
formula tells you to multiply them together (×).
Once a person gets over their fear of algebra and realizes how easy and useful it is, formulas become tremendously
useful, even empowering. All the information you need to solve problems can be gained in a glance. Let’s try an
example. Find the area of the following rectangle:
The formula is:
Substitute them in
A= L × W
0
0
A = (5 ) × (3 )
so measure the rectangle to find the length and width
and then do the indicated math operation
A = 15 sq. ft.
Distance Problems
Now we’re ready to take on some problems from Chapter 1. You were given the formula for doing distance problems:
D=v×t
The D indicates that the formula is set up to find a distance.
The v and t tell us what quantities we need to know in order to find the distance.
v stands for velocity (how fast something is going)
t stands for the amount of time an object goes that velocity
The × tells us exactly what to do with these two quantities once we know them.
Example:
Find the distance a plane travels at 620 km/h for 3.3 hours.
D=
v
×
t
D = (620 km/h) × (3.3 hours)
D = 2046 km
Trickier Example: Find the distance a rocket travels at 1620 km/hr for 20 minutes
Since the velocity of the rocket is given in km per hr, the time must be converted to hours as well: 20 minutes will be
a part of an hour found by dividing 20 by the 60 minutes in an hour:
20/60 = 1/3 hour
10
Now you can use the distance formula as before:
D=
v
×
t
D = (1620 km/hr) × (1/3 hr)
D = 540 km
Solve the following problems:
1. How far does a person walk at 4.4 km/hr for 3 hours?
2. What distance does a space rocket cover at 12,250 km/hr for 60 days?
3. How far does a projectile go at 1200 meters per second for one minute?
Readjusting Formulas to Solve Other Problems
Formulas can be rearranged to solve other problems. For example:
How long would it take for a rocket to go 500,000,000 km at 2500 km/hr?
Here’s how the formula can be rearranged to solve this problem. Our original formula is
D=v×t
This formula can actually be written in an even simpler form:
D=v t
Mathematicians are somewhat lazy people in that if they can find a way to avoid writing something, they do. In this
case, when two quantities are written next to each other in algebra with no operational sign between them, it is
understood that the two quantities are to be multiplied times each other.
Now we can do some rearranging. A basic rule of algebra is that you can do whatever you want (whatever you find
useful) to one side of an equation as long as you do the exact same thing to the other side. Watch what happens if
we divide both sides of the formula by v :
D=v t
D vt
=
v
v
Because any quantity divided by itself is 1, the v on the top on the right side and v on the bottom of the right side
cancel each other out. All that remains on the right side is the t. So the formula now reads:
D
=t
v
Better yet, we can turn the equation around:
t=
D
v
Now the formula is set up to find the time (t) if you know the distance (D) and the velocity (v).
Solve the following problems:
4. How long would it take a car to travel 840 km at an average speed of 85 km/h?
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5. How much time would it take an airplane to travel 3200 km at 500 miles per hour?
6. Rearrange the distance formula so it can be used to find velocity.
7. How fast would a person have to run (on average) to cover 500 meters in 40 seconds?
8. Express the answer for problem 4 in km/h.
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