Big Bang Activity
Introduction: In the 1920s, astronomer Edwin
Hubble realized that light coming from galaxies is
shifted into the longer, red wavelengths. This would
indicate that they are moving away from Earth. By
carefully observing the light from galaxies at
different distances from Earth, he determined that
the farther something was from Earth, the faster it
seemed to be moving away. This relationship has
become known as Hubble's Law.
Hubble’s discovery helped lead to the current
theory of the origin of the universe. In this lab, you will make a model of what Hubble
observed and use it to draw conclusions about the nature of the universe.
Materials
Balloon
Marker
String
Measuring Tape
Procedure
1. Partially inflate the balloon.
2. Hold the balloon so the air does not escape.
3. Draw six evenly spaced dots on the balloon
with the marker.
4. Label the first dot “MW” to represent the Milky Way Galaxy”, Label the next five dots,
G1, G2, G3, G4 and G5
5. Using the string, measure the distance between the ruler, measure the distance, in
cm (1 cm=1 km), from the Milky Way to each of the other galaxies
6. Record your measurements on data table under Distance @Time=0 (column 3)
7. Inflate the balloon some more
8. Observe what happens to the dots
9. Pin the balloon closed and measure the distance from Milky Way to each of the
galaxies.
10. Record your data under 1 second
11. Repeat Steps for 2 second and 3 second
Graph on the x-axis
Column 1
Current distances of Galaxies
(in Mpc)
Mpc=mili parce
miliparsec a unit of length
used to measure large
distances to objects
outside the Solar System.
1 mpc
2 mpc
3mpc
4 mpc
5 mpc
Column 2
Column 3
Column 4
Column 5
Column 6
1 cm=1 km
Distance
@Time=0
In Km
Distance Distance Distance
@1
@2
@3
second seconds seconds
In Km
In Km
In Km
Column 7
Total
distance
from Milky
Way
(Column 7Column 3)
Galaxy 1
distance to
Milky Way
Galaxy 2
distance to
Milky Way
Galaxy 3
distance to
Milky Way
Galaxy 4
distance to
Milky Way
Galaxy 5
distance to
Milky Way
Questions:
1. In your balloon model, describe the motion of the galaxies relative to one another.
2. In your balloon model, which galaxy’s distance changed the most?
3. In your balloon model, which galaxy’s distance changed the least?
4. Based on your balloon model, is the Universe expanding, contracting, or staying the same?
5. What if you took the air out of the balloon, what would happen to the dots?
6. How does that model “going back in time”?
Graph on
the y-axis
Column 8
Average
Velocity
of galaxy
(Column
7/3
seconds)
7. What if you took more and more air out, making it smaller and smaller; for billions of years!!
What would you have?
Graph: The current distance of galaxies (column 1) vs. Velocity (column 8)
Questions
8. What is the variable on the x-axis of your graph? What is the unit?
9. What is the variable on the y-axis of your graph? What is the unit?
10. What is the relationship between the distance of
galaxies and their velocity (describe the slope of the
line)?
11. Look at Hubble’s data, does you balloon model data
look similar? How?
12. What parts of the Big Bang theory does your model allow you to verify?
13. How is your model similar to Hubble’s observations and how is your model different?
14. What part of the graph are you “going back in time”?
15. What are some of the advantages and disadvantage of using your model to study the Big Bang
Theory?
16. Does your model PROVE the Big Bang Theory? Explain.