8B30.95 - Forward, Backward, and Side Scattering - Zodiacal Light

Code Number:
8B30.95
Demo Title:
Forward, Backward, and Side Scattering - Zodiacal Light
Condition:
Excellent
Principle:
Scattering
Area of Study:
Stellar Astronomy
Equipment:
Laser and Tank with Fluorescein dye, small water tank, coffee creamer, green laser pointer with mounting apparatus, Lazy Susan.
Procedure:

Aim the laser into one of the ends of the large fish tank containing the fluorescein dye or a small amount of Pine-Sol.  Then, you can either turn the table or walk around the table, while observing the different amounts of scattering.  There will be a pronounced amount of forward scattering in this demonstration. 

Attach the laser assembly to the small tank, fill it to approximately 2/3 full and place this onto the Lazy Suzan.  Add powdered coffee creamer to the water until the laser beam looks to be completely scattered about 1/2 way through its travel through the tank.  The laser beam is quite visible when viewed behind the laser or in the backscattered orientation, seems to travel about 1/2 way through the tank before being completely scattered when observed from the side, and seems to be completely scattered with no clear laser beam source when viewed from the forward scattered orientation.

References:
  • Jearl Walker, "6.149, Zodiacal Light, Gegenschein and Other Nocturnal Lights", The Flying Circus of Physics Ed. 2, p. 302.


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