for “What We Learn from Hubble”
•Make a time
line of the journey of a photon from a quasar.
•Here is an
interesting activity to show how light is affected by the mass of a star
or planet it travels by.
To demonstrate general relativity, get a large sheet, a marble, tennis
ball, softball and basketball. Have about 8 friends hold the sheet around
the edge so that it is flat and taut. Have another friend roll the marble
across the middle of the sheet and observe the motion. It should travel
in a straight path.
Now place the tennis ball in the middle of the sheet and repeat the experiment.
The marble should curve slightly. Repeat with the softball and basketball.
As the mass of the ball in the center goes up, the "fabric of space"
is warped more, so the marble begins to curve more and more toward the
center. If the curve is great enough, it will even "orbit" the
central ball. If you were to use a bowling ball, chances are the marble
would fall right in. As mass increases, so does the curvature of space
resulting in more gravity. That's why ultra massive objects like black
holes pull everything towards them.