On 8/15/2007, Arno Wagner posted this:
In comp.sys.ibm.pc.hardware.misc William Sommerwerck
wrote:
I use a few of them around the house, driven by standard
wall-plate residential dimmers.

Rheostats? Triacs? I'm not familiar with the current technology. (X-10 is
triac-controlled, I believe.)


As you say, the color temperature is very constant over a
usable range of intensities compared to incadescent PAR bulbs.

Actually, I didn't say that, but you'd expect it to be so, given that a
fluorescent lamp is a quantum device.

Very much so, but mostly in the same sense that a glowing
pice of metal is a quantum device....

Arno

No, not at all in the same *sense*, but to the same *degree*. The
fluorescents use electron transitions in Hg to generate a line
spectrum, and then a fluorescent coating inside the bulb to convert the
lines in question into new lines and bands. This is in no way
comparable to black-body radiation, which is a continuum. This, of
course, is an *opinion* :-)

However, both are still quantum-mechanical devices at bottom. In fact,
it has been said that it was trying to solve the BB radiation problem
that led Planck to the discovery of his constant: he took the limit of
something as some differential went to zero and it didn't work. But he
got the right answer when he set the differential to a finite value,
around 6.27E-27, IIRC.

Close (sort of): Google gives me "Planck's constant = 6.626068 × 10-34
m2 kg / s", so I left out the second 6 - but I am used to it in cgs,
rather than mks, so the exponent is correct. That *would* be more
believable if I had expressed the units, erg-sec, above :-)

--
Gene E. Bloch (Gino)
letters617blochg3251
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