GK-12 Sensors!
Portable Module
Title: Black Holes
Author: Stephanie Pitcher
Discipline: Earth Science/ Integrated Science – Freshman level
Introduction:
This module includes a powerpoint presentation about black holes. It shows some good
pictures produced by NASA instruments/spacecrafts - (sensors). The presentation
discusses how black holes are formed, how you can see black holes if they are black, and
some of the “signature” data that indicates a black hole is present. How technology
allows observations and research/data to be obtained from such phenomenom as black
holes. After the presentation, a simple demonstration is done to emphasize the effects of
gravity and the behavior of black hole spirals. Then an activity can be done modeling a
star and its collapse into a black hole. This activity focuses on density relating to black
holes.
Learning Results:
Science Standards:
Standard A: Science as Inquiry
Standard D: Structure and Evolution of the Universe
Also touch in topics:
Motions and forces, conservation of engery and increase in disorder, and
interactions of matter and energy
Math Standards:
Process Standards
Number and Operations
Algebra
Measurement
Required Equipment:
For the Demo:
-pie dish (8” x 1 1/2”) foil or glass
-8oz. bottle of light corn syrup
-1 large Super Ball
-food coloring (2 colors)
-rainbow colored confection cake decoration stars
-marker and ruler to mark pie pan in 1/8ths
For Star-Black Hole Activity:
-three 30-35 cm sheets of aluminum foil
-1 balloon
-1 tape measure
-1 scale (that weighs to a tenth of a gram)
-1 graphics calculator
Procedure:
Demonstration:
Setup Directions:
1. Using a ruler and a marker, draw lines to segment the pie dish into 8 equal
sections
2. Pour ½ a bottle (8oz.) of light corn syrup to cover the bottom of the dish
3. Place the super ball in the center of the pie dish in the light corn syrup
4. Place 4 confection stars of different colors in a line to the left of the super ball
5. Place 4 confection stars of different colors in a line directly below the super ball
6. Place 1 drop of blue food coloring close, about ½ in., but not touching the right
side of the super ball
7. Place 1 drop of green food coloring in front of first and last star on left side of the
super ball
**The experiement should start immediately after setup so the corn syrup does not
stiffen**
Procedure for Demo:
Take turns slowly spinning the super ball (black hole) in a circle, always spinning it in
the same direction and observe how space (corn syrup) and matter (stars, gases, particles)
are affected by the black hole. Observe the twisting of space, formation of an accretion
disk, as well as the orbiting and capture of matter. Also notice that the star(s) furthest
away from the black hole remain stable.
Procedure for Black Hole Activity:
Procedure:
1. Blow up the balloon until the diameter is about 15 cm. Tie off the end. Cover
the inflated balloon with the sheets of aluminum foil. This will be your “Model
Star”.
2. Measure the circumference of the aluminum foil star. Repeat this 3 times using 3
different paths around the star. Calculated the mean of these 3 measurements. In
your data table, record this average value as Trial 1 Circumference.
3. Place the “Model Star” on the scale. Record the mass (grams) under Trial 1
Mass.
4. Now Supernova! Break your balloon by squeezing it. Gently shape the
aluminum foil back into a “sphere”. Measure the circumference of the now
collapsed “Model Star” three times. Average these 3 measurements. Record the
value as the Trial 2 Circumference.
5. Obtain the mass of the collapsed “Model Star” and record the value as Trial 2
Mass.
6. Squeeze the collapsed star a little more. Repeat the procedure for determining the
new average circumference and record your data as Trial 3.
7. Repeat the mass measurement and record your value appropriately.
8. Squeeze the collapsed star so that you make it as small as you possibly can.
Repeat the circumference and mass measurements and record the data. For each
circumference, calculate the radius of the sphere. Remember, this is done by
dividing the circumference by 2*. Record the results appropriately in your data
table.
9. Now calculate the volume [(4/3)* *r3] of the sphere for each radius.
10. Calculate the density. Remember that density is defined as mass/volume.
Expected results:
Demonstration:
While demonstrating, a description in detail will be given on the effects black holes have
on nearby space.
1. What happened to space near the black hole?
2. What happened to the stars near the black hole?
3. What happened to the star furthest away from the black hole? Why?
These concepts should be grasped, now that a visual demostration and discussion were
performed.
Activity:
The outcome of this activity will allow students to understand the concept of density.
How black holes form and the calculations and differences between circumference,
radius, volume, mass, and density. They will learn that the density increases as the
volume decreases, and the mass stays approximately the same.
Troubleshooting:
Demo:
This can be really messy, therefore, I use it as a demonstration rather than an activity. But
it could just as well be an activity for students.
Activity:
The biggest problem I’ve encountered is that the freshman get bogged down in the
calculation part and not understand the overall outcome of what is happening as their
model stars collapse and become more dense, and eventually turn into a black hole. To
overcome this issue, just make sure there is enough time at the end to compare answers
and ask them what they see happening according to their answers/calculations.
Resources: NASA/GSFC workshop, summer 2003
http://imagine.gsfc.nasa.gov/docs/teachers/blackholes/blackholes.html