Model a Black Hole
This demonstration allows for a visual depiction of the effect
of a large mass on the fabric of spacetime. In particular, what effect a
black hole does or does not have on the other stars around it and how that
effect depends on the mass of the black hole.
* large latex balloon cut open and pulled flat, or sheet of latex
* round bowl, 4"- 5" in diameter
* package of small round beads
* 1" solid ball bearing (the eraser end of a pencil can be used as
1. Tape the sheet of latex (this represents space-time) tightly across
the top of some round object...such as a bowl. The sheet should not be so
tight that it will tear if stretched further, but should be taut enough
that there are not any wrinkles!
2. Scatter a few beads on the sheet of latex (this represents matter
that is near the black hole).
Make sure they are spread out to all parts of the sheet.
3. Gently drop the ball bearing onto the sheet of latex (this
represents the black hole). Try not to let it bounce! If you don’t have a
ball bearing, gently push down on the center of the sheet with the eraser
end of a pencil.
4. Explain what happened to the matter when the black hole was put into
place. Why did this occur?
5. What would happen if the ball bearing was heavier (or if you push
harder on the pencil)? What physical analogy to the black hole may be
These Stars are Classified
Annie Jump Cannon (1863 - 1941) was known as the world’s expert
in the classification of stars. Her work laid the foundation for modern
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