We investigate if a period of time feels longer or shorter when people are bored compared to when they are not bored. Using independent samples, we obtain these estimates of the time period (in minutes):
Sample 1 (bored): = 14.5, s = 10.22, n = 28
Sample 2 (not bored): = 9.0, s = 14.6, n = 34
a) What are the null and alternative hypothesis in terms of Ha and Ho
b) Compute t obt
c) With alpha = .05, what is t crit
d) What should we conclude about this relationship?
e) Using our two approaches, how important is boredom in determining how quickly time seems to pass?
HR Diagram Activity (30 points)
Brief Overview of Activity: Use an HR diagram to learn about the differences between the stars in our stellar neighborhood and the brightest stars in the sky.
Required Items:this HR diagram, red & black ink pens.
Procedure:
On the HR diagram, plot each star from the "Brightest Stars Group" in black ink and then plot each star from the "Nearest Stars Group" in red ink.
Data for both groups of stars can be found below.
Describe any differences between the two groups of stars - such as their location on the diagram, color, mass, and the types of stars in each group.
Which of the two groups of stars is most representative of the vast majority stars in the universe?
Data
Brightest Stars Group
Name
Spectral Type
Absolute Mag
Sirius
A1
1.45
Canopus
F0
-5.63
Rigel Kentaurus
G2
4.39
Arcturus
K2
-0.32
Vega
A0
0.61
Capella
G8
-0.52
Rigel
B8
-7.01
Procyon
F5
2.66
Betelgeuse
M2
-5.48
Achernar
B3
-2.71
Hadar
B1
-4.78
Altair
A7
2.22
Aldebaran
K5
-0.63
Acrux
B0.5
-4.18
Spica
B1
-3.44
Antares
M1
-5.12
Fomalhaut
A3
1.75
Pollux
K0
1.07
Deneb
A2
-6.90
Mimosa
B0.5
-3.90
Nearest Stars Group
Name
Spectral Type
Absolute Mag
Sun
G2
4.83
Proxima Centauri
M5.5
15.48
Alpha Centauri A
G2
4.38
Alpha Centauri B
K0
5.71
Barnard's Star
M3.5
13.25
Wolf 359
M5.5
16.64
Lalande 21185
M2
10.44
Sirius A
A1
1.44
Sirius B
A2
11.34
Epsilon Eridani
K2
6.20
Lacaille 9352
M1
9.76
Ross 128
M4
13.53
61 Cygni A
K5
7.48
61 Cygni B
K7
8.31
Procyon A
F5
2.65
Procyon B
A0
12.98
Struve 2398
M3
11.17
Groombridge 34
M1.5
10.31
Epsilon Indi
K4
6.98
Tau Ceti
G8.5
5.68
Radioactive Dating Activity (due at Stage 2) (30 points)
Brief Overview of Activity: Radioactive decay is one of the sources of the heat that drive the Earth's geologic activity. Radioactive decay also allows us to date rocks and determine the age of the Earth and other solar system bodies.
Required Items: 36 coins, a calculator, pencil & paper.
Procedure:
In this activity you will simulate the radioactive decay of 36 atoms of a rare isotope of uranium, U-235. Uranium-235 has a half-life of 700 million years. Gather 36 coins and arrange them in a 6 x 6 grid with all of the coins facing heads up.
Flip each coin into the air and then place it back in its original location on the grid. This represents the passage of 1 half-life (700 million years for this example). The coins that came up heads represent atoms that have not .
We investigate if a period of time feels longer or shorter when pe.docx
1. We investigate if a period of time feels longer or shorter when
people are bored compared to when they are not bored. Using
independent samples, we obtain these estimates of the time
period (in minutes):
Sample 1 (bored): = 14.5, s = 10.22, n = 28
Sample 2 (not bored): = 9.0, s = 14.6, n = 34
a) What are the null and alternative hypothesis in terms of Ha
and Ho
b) Compute t obt
c) With alpha = .05, what is t crit
d) What should we conclude about this relationship?
e) Using our two approaches, how important is boredom in
determining how quickly time seems to pass?
HR Diagram Activity (30 points)
Brief Overview of Activity: Use an HR diagram to learn about
the differences between the stars in our stellar neighborhood
and the brightest stars in the sky.
Required Items:this HR diagram, red & black ink pens.
Procedure:
On the HR diagram, plot each star from the "Brightest Stars
Group" in black ink and then plot each star from the "Nearest
Stars Group" in red ink.
Data for both groups of stars can be found below.
Describe any differences between the two groups of stars - such
as their location on the diagram, color, mass, and the types of
stars in each group.
2. Which of the two groups of stars is most representative of the
vast majority stars in the universe?
Data
Brightest Stars Group
Name
Spectral Type
Absolute Mag
Sirius
A1
1.45
Canopus
F0
-5.63
Rigel Kentaurus
G2
4.39
Arcturus
K2
-0.32
Vega
A0
0.61
Capella
G8
-0.52
Rigel
B8
-7.01
Procyon
F5
2.66
Betelgeuse
M2
-5.48
Achernar
4. Absolute Mag
Sun
G2
4.83
Proxima Centauri
M5.5
15.48
Alpha Centauri A
G2
4.38
Alpha Centauri B
K0
5.71
Barnard's Star
M3.5
13.25
Wolf 359
M5.5
16.64
Lalande 21185
M2
10.44
Sirius A
A1
1.44
Sirius B
A2
11.34
Epsilon Eridani
K2
6.20
Lacaille 9352
M1
9.76
Ross 128
M4
5. 13.53
61 Cygni A
K5
7.48
61 Cygni B
K7
8.31
Procyon A
F5
2.65
Procyon B
A0
12.98
Struve 2398
M3
11.17
Groombridge 34
M1.5
10.31
Epsilon Indi
K4
6.98
Tau Ceti
G8.5
5.68
Radioactive Dating Activity (due at Stage 2) (30 points)
Brief Overview of Activity: Radioactive decay is one of the
sources of the heat that drive the Earth's geologic activity.
Radioactive decay also allows us to date rocks and determine
the age of the Earth and other solar system bodies.
Required Items: 36 coins, a calculator, pencil & paper.
Procedure:
In this activity you will simulate the radioactive decay of 36
6. atoms of a rare isotope of uranium, U-235. Uranium-235 has a
half-life of 700 million years. Gather 36 coins and arrange them
in a 6 x 6 grid with all of the coins facing heads up.
Flip each coin into the air and then place it back in its original
location on the grid. This represents the passage of 1 half-life
(700 million years for this example). The coins that came up
heads represent atoms that have not yet decayed; the coins that
came up tails represent atoms that have decayed. Record the
number of heads below.
Next flip each one of the remaining heads-up coins once and
place it back in its original location. 1.4 billion years have now
passed by (2 x 700 million). Record the number of remaining
heads below. Repeat this process until all coins are tails up.
_______ Original number of U-235 atoms
_______ Remaining number of U-235 atoms after 1st flip
_______ Remaining number of U-235 atoms after 2nd flip
Add additional lines as needed.
Questions:
How many half-lives did it take for all of the atoms to decay?
How many years does that equate to?
Do you think everyone in class will get the same answer? Why?
Stage 3 - Actual Observations (8% of course grade)
Diameter of the Sun Activity (25 points)
Brief Overview of Activity: A pinhole can form an image in
much the same way as a lens. Measuring the size of the Sun's
projected image and the distance between the pinhole and the
image, you will be able to calculate the diameter of the Sun.
Required Items: a friend to help you, a broom handle (or mop
handle or long straight piece of wood of similar dimensions), a
ruler (marked in centimeters), two envelopes (or two 5 x 7
index cards), a pencil, masking tape, one stickpin.
Number of Observations needed: 1
Timing of Observations: near noon on a bright sunny day
7. Procedure:
Preparation: Use the stickpin to poke a small hole near the
center of one of the envelopes. Mark a location near the top of
the broom handle with masking tape (this is where your friend
will hold the envelope with the pin-hole). Mark another location
near the end of the broom handle with masking tape (this is
where you will observe and mark the image). Carefully measure
the distance between your two marked locations on your broom
handle. Make your measurement to the nearest 0.1 centimeter
and record here: ___________ cm.
Observation: Caution: never stare directly at the Sun. Gather
your friend, marked broom handle, two envelopes, pencil, and
then head outside. With your friend holding the envelope with
the pinhole at the upper marked position and you holding the
other envelope at the lower marked location, align the broom
handle such that a small faint image of the Sun's disk is seen on
the lower envelope. You may find it convenient to actually sit
on the ground for this procedure. With a pencil, carefully mark
the location of opposite sides of the Sun's disk. Here is a link
showing a diagram of the setup.
Calculation: From your marked envelope, carefully measure the
size of the projected image of the Sun's disk to the nearest 0.1
centimeter and record here: __________ cm.
Next, use the relationship below to calculate the Sun's diameter
in kilometers. Note that the distance to the Sun is 1.5 x
10 8 km.
Sun's diameter in kilometers image diameter in
centimeters
------------------------------------- = -----------------------------------
-------
Distance to the Sun in kilometers distance between image
and pinhole in cm
Record your calculated value for the diameter of the Sun
______________________ km
8. SetupDiagram
Moon Position Activity (25 points)
Brief Overview of Activity: Over a period of at least three
consecutive evenings, you will make careful observation of the
Moon's changes in appearance and position.
Required Items: a notebook to take notes or make a sketch
(bring your red flashlight), you may take digital photos if you
wish.
Number of Observations needed: 3
Timing of Observations: 3 consecutive nights, around (and
after) sunset, a few days after the Moon is new. Your instructor
will inform you what the appropriate viewing days are in the
term.
Procedure:
Choose a location with a good view of the western horizon from
which you can clearly observe the Sun at sunset. Since we will
be timing our observations a few days after the Moon is new,
the Moon should be visible in the sky at (and for a while after)
sunset. It is important that you make all of your observations
from the same location and at the same time. You may want to
mark the location with a piece of tape to insure you are
observing from the same location each time.
First measurement: This measurement is important. It will be
used as a reference point for all future measurements. Arrive a
little early and try to find a suitable reference object in the
distance near the horizon. Look for a distinctive tree, building,
rock formation, or other object. Pick something you will
remember and be able to easily spot each time you come to
observe. Mark the location and description of your reference
object in your notebook.
For Each Observation: Make a note in your notebook about
appearance of the Moon and its location in the sky. You may
make a sketch if you wish. Note any changes from the previous
day's observation. Be sure to note the location, date, and time of
9. your observations.
Location of Observations:
_______________________________________________
Observation (1) Date ____________________Time __________
pm
· Horizontal angular measurement ___________ degrees
· Vertical angular measurement ___________ degrees
· Appearance
_____________________________________________
Observation (2) Date ____________________Time __________
pm
· Horizontal angular measurement ___________ degrees
· Vertical angular measurement ___________ degrees
· Appearance
_____________________________________________
Observation (3) Date ____________________Time __________
pm
· Horizontal angular measurement ___________ degrees
· Vertical angular measurement ___________ degrees
· Appearance
_____________________________________________
Angular Measurement: As shown below, you can use your
fingers (or hand) to estimate angles. Using your measured
angles, it is possible to determine the angular change in the
Moon's position from day to day. You will need to make two
angular measurements for each observation - one horizontal
angular measurement and one vertical angular measurement.
Your horizontal measurements are made from the reference
object/point to the Moon. Your vertical measurements are made
from the horizon to the Moon.
Fully extend your arm and use the finger/hand guidelines to
make your angular measurements.
10. Questions:
Describe any changes in the Moon's appearance from
observation to observation.
Describe any change in Moon's position in the sky from
observation to observation.
Using the methods laid out above, what is your estimate of the
daily amount of angular change in the Moon's position
Star Count Activity (25 points)
Brief Overview of Activity: Determine the number of stars
visible to the naked eye by collecting sample star counts over a
small area of the sky.
Required Items: a ruler (marked in centimeters), one small
cardboard tube (the center tube from a roll of toilet paper is
ideal. Note: the length of the tube must be greater than its
width.), red-light flashlight (or tape a piece of red cellophane or
plastic over a white-light flashlight). Using a regular white-
light flashlight will interfere with your night vision.
Number of Observations needed: 3, each at a different location
as detailed below.
Timing of Observations: clear, dark moonless night
Procedure:
Preparation: Carefully measure the length of your cardboard
tube. Make your measurement to the nearest 0.1 centimeter
and record here: L = _______ cm.
Next, carefully measure the diameter of your cardboard tube.
Make your measurement to the nearest 0.1 centimeter
and record here: D = _______ cm.
Observation: On a clear, dark, moonless night, allow a few
minutes for your eyes to adapt to the dark, then hold the tube up
to your eye then count and record the number of stars that you
can see through the tube. Hold the tube steady, with your eye at
the center of the tube's opening, during each star count. Do this
ten times, choosing random areas of the sky to measure. Be sure
11. to sample all directions equally.
Calculation: You can estimate the total number of naked-eye
stars visible in the night sky by using: the length (L) of the
cardboard tube, the diameter (D) of the cardboard tube, and the
number of stars in your sample (NSAMPLE). Use your
measurements and the formula below to estimate the number of
naked-eye stars visible in the night sky. For anyone interested, a
derivation of this formula can be found at the bottom of the
page.
Your answer is an estimate of the total number of stars in the
night sky that are visible to the naked eye at this particular
location.
Follow this procedure three times: once in a city, once in a rural
location away from city lights and once in another location. In
the end, you should have three different estimations of stars for
three different locations. Make sure you record the locations,
dates, and times of your three sets of observations on the next
page.
Star Count Observations and Data
Location of Observation (1):
____________________________________________
Date ____________________Time __________ pm
Total Number of Sample Stars Observed ___________
Calculated Number of Visible Stars ___________
Location of Observation (2):
____________________________________________
Date ____________________Time __________ pm
Total Number of Sample Stars Observed ___________
Calculated Number of Visible Stars ___________
Location of Observation (3):
____________________________________________
12. Date ____________________Time __________ pm
Total Number of Sample Stars Observed ___________
Calculated Number of Visible Stars _________________
Question: Discuss possible reasons why your observed number
of stars might be different at each of your observation
locations.
If you want to know where the formula comes from.... continue
reading below...
Constellation Activity (25 points)
Brief Overview of Activity: Locate five constellations.
Required Items: Night Sky Planisphere, red-light flashlight (or
tape a piece of red cellophane or plastic over a white-light
flashlight). Using a regular white-light flashlight will interfere
with your night vision.
Number of Observations needed: 1
Timing of Observations: a clear, dark night when the moon is
not prominent (ideally)
Use your Night Sky Planisphere to identify any five
constellations in the night sky. If you are in the Northern
Hemisphere, also find the Big Dipper and the North Star
(Polaris). Submit the names of the five constellations you
found, describe how you found Polaris, and comment about how
easy (or hard) it was to use the star chart to locate
constellations. Do the constellations in the sky look like the
ones on the star chart? If not, how do they differ?