Date: Wed, 1 Oct 1997 13:26:55 -0500 (CDT) From: Paul Burkhardt <burkhard@aries.scs.uiuc.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3806$foo@default> Subject: Artificial light
Matt Drake and others,
> Paul, I do not know why you insist on interpreting 'cool' and 'warm'
> as in reference to temperatures. 'Cool' and 'Warm' do not refer to
> temperature in this context. That is fairly obvious.
> By 'cool' and 'warm' spectrum of light I was refering to the spectrum
> of visible light on the bluish side (cool) and the reddish side (red).
> Here is a bit of information: When light manufacturers call their
> flourescent tubes COOL WHITE or WARM, it is not because the cool
> whites are cool and good for keeping drinks cold, and that the warm
> are suitable to cook turkey dinner under. They are talking about the
> COLORS, not anything to do with TEMPERATURE!!!!
You need to think about these terms a little harder. The terms cool and
warm in this context have everything to do with temperature! Why do you
think they use the terms cool and warm? Why not happy or sad, or rich
and poor?
I was *not* suggesting that these lights produce cold or heat, only the
fact that the terms cool and warm are not correct nor good descriptions
for the spectrum of electromagnetic radiation since they are too ambiguous
and subjective. Is 'white' cool or hot? How about yellow? That is why I
initially brought up the other non-visible non-color frequencies. Does a
'cool' light produce more ultravoilet radiation than a 'warm' light? This
is important to know since we are interested in *full* spectrum light!
These plants have evolved in full spectrum light, including UV, IR,
Microwaves, X-rays, gamma rays, etc. and they are all important to
molecular and sub-molecular processes. I doubt if plants can survive on a
regiment of just blue and red light.
> TOPIC, which was LIGHTS. Surely you are not arguing that because
> 'cool' and 'warm' have more than one meaning (that of temperature) and
> that using them in the context of one of their other definitions is
> MISINFORMATION?
Cool and warm only have one meaning! When I describe someone as
'cool-headed', I am not saying that his head produces coolness! It
suggests that person has a temperment which is analagous to the state of
coolness. Using these terms in the context of the *spectrum* of light
*is* misinformation! I believe I have already explained this, but if you
still don't understand, I suggest you read a few physics or chemistry texts.
> > It is the terms, 'warm and cool', which are irrelevant to the growth
> > of plants, because no plants can survive on just those 'warm and
> > 'cool' frequencies alone.
> Not true. The reddish spectrum of light has impact on flowering, and
> bluish on normal growth and compact leaf growth. Selection of
You have again failed to understand my statement. It is the terms 'cool'
and 'warm' which are irrelevant to plant growth, *not* the blue and red
frequencies of light!
> If you do not believe that different spectrums of light affect plant
> growth differently, than it is up to you to find the research. I
Again, you need to read my posts more carefully! I have been trying to
point out to you that the other frequencies of light are important and
do indeed affect growth in different extents! Other frequencies, being
more than just blue and red light or the visible region.
> time in citing references. Use of 'cool' and 'warm' by light
> manufacturers and others in general is also common language; if you
Yes, and I was trying to clarify to you and Matt Miller that in general,
common language is not always correct! Please look up the definition of
misnomers if you, again, do not understand my statement.
I will *not* continue this particular thread on the list any further. If
you or anyone would like to discuss it further, please email me
personally.
My sincere apologies to everyone else on the list who have found these
posts uninteresting.
Paul Burkhardt
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