Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: white

Larry Woolf responds to the "what makes clouds white?"
request with subject line "Re: hoaxes".

So as keep the subject line appropriately named, I
repeat his quote from Hewitt here and refer readers to
<http://lists.nau.edu/cgi-bin/wa?A2=ind0304&L=phys-l&F=&S=&P=12386>
although I suspect the link won't survive (even with
the brackets).

Hewitt: "A cloud is composed of a variety of droplet sizes.
The tiniest
scatter blue, slightly larger scatter green, and still larger
scatter reds.
The overall result is a white cloud."

This is mistake, not a hoax.

Rather than repeat what has already been written,
I suggest the following thought experiment.

The question is whether...

#1: Do small cloud drops preferentially scatter shorter
wavelengths and large cloud drops preferentially
scatter long wavelengths?

...or...

#2: Are all cloud drops so large as to scatter both short
and long wavelengths equally well?

Both would produce white light. However, theory #1
predicts that clouds with uniform cloud droplet size
(if they exist; a common charge of those who explain
corona phenomena) would be a specific color while
theory #2 predicts those clouds would still be white.

____________________________________________
Robert Cohen; rcohen@po-box.esu.edu; 570-422-3428; http://www.esu.edu/~bbq
Physics, East Stroudsburg Univ., E. Stroudsburg, PA 18301