ISP205, Section 3, Hufnagel & Stein
Random Walk, 13 March 1997
Name: ________________________
Student Number: ______________
We are going to turn the classroom into a model of the Sun, using
balloons to represent photons. The center of the room will represent the
core of the Sun, and the rest of the room the outer parts of the Sun. The
last seats at the edge of the room are the surface of the Sun where
photons escape (the photosphere). You are a particle the photon bounces
off. Balloons will be given to students in the "core" of the classroom to
start their motion, as this is where the Sun generates its energy. Everyone
will then tap the balloons gently to each other to simulate the "random walk"
of photons through the Sun. Don't try to direct their motion! Any photons
hitting the walls or getting to the last persons at the edge of the room (i.e.,
arriving at the Solar surface), will "escape" and be taken out of the game.
- Predict how long it will take half the balloons to reach the edge of
the room. Guesses are completely acceptable.
__________
- The instructors will stop the game after about half of the
balloons (photons) have reached the edges of the room (escaped
from the Sun). Record how long this took.
__________
- Compare your initial guess to the final time.
SHORTER ____ or LONGER ___
- How many times longer does it take for a balloon to randomly walk from the
center to the edge of the room, compared to the time it takes for it to travel
that distance directly?
__________
- Explain how this game relates to how photons carry energy from
the core to the surface of the sun.
This page has been accessed
times.
Visions of the Universe
Beth Hufnagel's home page, email:
hufnage4@pilot.msu.edu
Bob Stein's home page, email:
steinr@pilot.msu.edu