PURPOSE: To demonstrate the concept of the expansion of the universe occurs in all directions.
DESCRIPTION: A large, 8 foot diameter deflated weather balloon is shown in the above photo at left. The inflated balloon is seen at right. The balloon is marked with an equilateral triangle of black spots, and also some additional spots that are both close together and far apart. The spots represent galaxies. The balloon is inflated using the compressed airline. Flexible measuring tape can be used to show that the expansion bewteen the spots is uniform in all directions. The inflation rate between two closely spaced spots can be compared to the inflation rate of two widely seperated spots.
Note that inflation is slow. It takes about five minutes. Slow inflation is done so that the hissing of the airline does not become loud. It will takes 10 minutes to deflate. The deflating is performed by disconnecting the airline valve.
A smaller balloon is available for use in the 1st floor classrooms.
EQUIPMENT: Balloon.
SETUP NOTES: Use either a blower, an air line. Flexible measuring tape.
Updated by Jun Qi in 3/20/2000