6B10.25 - Wien's Law - Planetary Sunlight Intensity

Code Number:
6B10.25
Demo Title:
Wien's Law - Planetary Sunlight Intensity
Condition:
Good
Principle:
Intensity vs. Distance
Area of Study:
Astronomy
Equipment:
Light bulbs (0.25 W, 100 W, 1000 W), Socket, Variac.
Procedure:

See also 6B10.25 in Astronomy.

Put the 1000 watt bulb on one Variac, the 100 watt bulb on another Variac and the 1/4th watt bulb on a 'D' cell battery.  Turn them all on and observe the relative intensities.  The scale of these intensities:

Intensity of sunlight as seen from Mercury = 1000 watts.

Intensity of sunlight as seen from Earth = 100 watts.

Intensity of sunlight as seen from Pluto = 1/4th watt.

References:
  • Chirstopher Sirola, "Stellar photometry in an introductory physics lab (or, translating flux into magnitudes)", TPT, Vol. 61, #4, Apr. 2023, p. 310.


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