Date: Wed, 8 Oct 1997 13:03:11 -0500 (EST) From: jcavanau@indyunix.iupui.edu (john e. cavanaugh) To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3904$foo@default> Subject: Re: lights
>I believe the concept of hot and cold colours arose when primitive
>man discovered that things glowed red when hot, and that ice
>looked blueish when reflecting the sky. Now some of us are a bit
>less primitive and know that white hot is hotter than red hot etc,
>the terms hot, warm, cool and cold are a ubiquitous relic.
Your guess is as good as mine. All I know is that when you buy
color-balanced film, you need to check the Temperature in Degrees Kelvin
between the light source and the film. I have heard anecdotal stories about
this relating to the actual absolute temperature (degrees Kelvin is an
absolute version of centigrade) of a standard glowing tungsten filament -
Kodak pamphlets indicate this but don't go into details. Anyway, the lights
themselves come labeled as to temperature in degrees Kelvin, and if you use
a mismatch of film-to-lights your photos get too red-yellow or too
green-blue.
I do not claim credit for this terminology, it's there in the pamphlets and
proprietary textbooks. If anyone has a problem with this, take it up with
Kodak and the lighting industry. Save your flames for those who actually
deserve them.
On a different matter,
although this is again late, a few comments on safety precations when
working with sand, peat, etc. OSHA regulation require those with
occupational exposures to these and other particulate compounds to were
airway filters of some sort. Yes, it's true one can get serious lung
infections from sand (but not peat). The more serious of these are
cryptococcosis and the ornithoses. Both of these can lead to chronic and
potetially debilitating lung infections which are often missed by
clinicians searching for more usual entities. Both of these diseases are
related to spores which are found in bird droppings in the sand, and have
somewhat of a restricted natural distribution - but bags of sand could come
from anywhere. However, infections are not the only problem or the most
common. A second health risk found with sand particulates is that of
heavy-metals such as berylium, nickel, barium sulfate, or tin oxide. All of
these can cause serious, debillitating chronic lung disease, and would of
course not be prevented by any sterilization techniques. The third health
risk, which would be equally tru for milled peat as for sand (and would
include wood chips, saw dust, bark mutch, or anything with dust) is that of
an allergic reaction. These can become chronic and when they do can often
lead to severe lung diseases. All of the above can range in severity from
nothing at all (over 99% of all cases) to minor temporary respiratory
complaints all the way to severe pulmonary fibrosis (scarring) and even
death. Black lung (coalminer's lung)is a close relative or variant of these
diseases.
So wear a mask when dealing with particulate material, even if it's been
sterilized.
Enjoy,
jec
John E. Cavanaugh, MD, MS, DABP
Fellow of Forensic Pathology
Indiana University Medical Center
Department of Pathology & Laboratory Medicine
Division of Forensic Pathology
Room 157 Van Nuys Medical Science Building,
635 Barnhill Drive, Indianapolis IN 46202-5120
Phone (317) 274-2973 Fax (317) 278-0221
Direct line (317) 278-0462
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