I just ran across this cgs unit, the Rayleigh, and wonder if there is a
corresponding SI unit.
Also, is the given equivalence correct?
The article notes that the Rayleigh is equal to a given number of photons per
square metre per steradian. It does't seem to be correct to me.
If one of the two units includes "per unit time" (per second) mustn't the other
also involve "per unit time"?
Similarly, if one unit involves "per unit solid angle" (per steradian), mustn't
the other also include "per unit solid angle"?
Otherwise, the two measures do not have dimensional consistency.
Am I right, or am I overlooking something.
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Here is the definition I found:
Rayleighs
a CGS unit of light intensity used in astronomy and physics to measure the
brightness of the night sky, auroras, etc. One rayleigh represents the light
intensity of one million photons of light emitted in all directions per square
centimeter of receiver per second, or, in SI units, 795.775 x 106 per square
meter per steradian (m-2·sr-1).
From the web site:
> http://www.scribd.com/doc/32965079/A-Dictionary-of-Units-of-Measurement
(Click on R and scroll down to find the Rayleigh.)
