Welcome Assignment
August 9 & 10, 2011
Planner: Wear covered shoes for rest of week
Type up lab report as the information comes
Get Science Notebook:
The Universe
1.Make a circle map – brainstorm all the things you
can think of in the universe (space).
2.In your lab group categorize the items you put
down into a KWL Chart.
K – What you
know
W – What you L – What you
want to know learned
How do scientist know what’s
out there?
Write some questions you have about the universe.
KWL
Complete the W part of the KWL Chart.
K – What you
know
W – What you L – What you
want to know learned
Welcome Assignment:
Get Science Notebook –
Write title:
How Far is that Star?
WEAR Covered Shoes August 10 – 12
TYPED Lab Report due August 17 = Period 1
TYPED Lab Report due August 18 = Period 2, 4, 5, 6
Science Investigation:
Research Question/Purpose
Background Information/Equations
Hypothesis
Materials
Procedure
Data/Observations
Data Analysis & Calculations
Conclusion
Research Question/Purpose
How can parallax be used to
determine distances from earth
to nearby stars?
Skills
Measure distances between two points
Calculate the distance to an object using ratios
of measured values;
Compare the calculated value to the measured
value;
Predict the parallax of an object at different
distances.
Background
Information/Equations
Write from your past experience:
What do you notice when you view a fast
moving object up close, and a fast moving
object from far away? (think about an
airplane in the sky)
Distance = Diameter X Focal Length
Parallax Shift
Hypothesis
If…Then…Because….
Materials
Masking tape
Metric Ruler
Black and red pencils
Meter Stick
Extension cord
Pen
Lamp, 100 watt Lightbulb
Paper
Copier Paper Box (no lid)
Flat Table
Paper Clips
Calculator
Procedure – Part 1
1.
Place the lamp on a table in the middle of the classroom
2.
Make a small hole in the middle of the box
3.
Place the box on a flat table so the hole points toward the
light
4.
Line the left side of the box with the table
5.
Put a small piece of tape on the table below the hole. Use
the pen to make a mark on the tape directly below the hole.
6.
Procedure
Part
2
Label sheet of copy paper “Star 1”
7.
Place it inside the box
8.
Turn off the classroom lights and turn on the lamp
9.
RED Pen – Mark the paper where you see a dot of light.
10. Move the box so the right edge of the box lines up with the right edge of the
table
11. Put another small piece of tape under the new location of the hole, and make a
mark to record the specific position (telescope 6 months later)
12. Regular Pencil – mark the second dot B. Dot B represents the image of the star
as seen 6 months later from the other side of Earth’s orbit.
13. Remove the paper.
Measurements
14. Measure and record the distance in millimeters between dots A and
B. This distance represents the parallax shift for Star 1
15. Measure and record the distance from the hole (lens) to the paper
(film) at the back of the box in millimeters. This distance
represents the focal length of our telescope.
16. Measure and record the distance in millimeters between the marks
on the two pieces of masking tape. This distance represents the
diameter of Earth’s orbit.
17. Use a meter stick to measure the actual distance from the box to
the bulb. How did your calculations for Star compare with the
actual distance
Data/Observations
Star
Parallax
Shift
(mm)
Focal
Length
(mm)
Diameter
of orbit
(mm)
Calculate
d
Distance
to Star
(mm)
Calculate
d
Distance
to Star
(m)
Actual
Distance
to Star
(m)
Data Analysis & Calculations
Use the following formula to calculate the distance from the telescope
to Star 1.
Distance = Diameter X Focal Length
Parallax Shift
What happened to the dot of light for each star when you moved to
your model telescope from one side of Earth’s orbit to the other?
What caused the apparent change in position of the dots of light for
each star? Explain.
Conclusion
Is the parallax shift greater or smaller the farther away the star is? Relate
each star’s parallax shift to its distance from Earth. Use data to support
your statement.
Validate or Refute your Hypothesis. Use data to support your statement.
Identify any errors in calculations, measurement, etc.
Think about your experience (fast moving objects) explain how it relates to
this lab?
How can parallax be used to determine distances from earth to nearby
stars? Explain how this method works.
Would this method work for objects very close?
Would this method work for objects very far?
Would this method work for all objects in the universe?