In which I kvetch about fluorescents

[zdashamber]

Homer: Come on, Flanders, there's gotta be something you hate. What about mosquito bites?
Ned: Mmm mmm! Sure are fun to scratch! Mmm! Satisfying!
Homer: What about, uhhhhh, fluorescent lights?
Ned: Oooh, they hum like angels! You're never lonely if you've got a fluorescent light!

I want to like fluorescent lights. Really, I mean, there's the living-lightly thing, and there's the not-burning-out-suddenly thing, and there's the freeging-politicians-jamming-'em-in-our-face thing. But they just suck. They create crappy light.

I've mentioned this to my friends some, and they're like "Oh, but those are bulbs you got from Ikea years ago! Things are advancing really fast!" But I've been doing a lot of research about light sources lately for an idea I have on backlit mouldings, and I can tell you that the trouble is: every single way to make light today that doesn't involve "heating something up" (ie, incandescents or fire) involves quantized light. We excite this thing electrically, and then it drops back down an energy level, releasing a packet of photons at a certain wavelength. Fluorescents have a vapor in them that glows at high UV energy, and coatings on the glass that are excited by that energy and then put out visible light droppings. EL, neon, LEDs, directly drop photon packets.

Here's a typical "cool white" modern fluorescent bulb's spectrum, from wikipedia. Then, a typical "soft white" incandescent bulb's spectrum from this page of many spectra. Then, sunlight. (I tried to find a directly comparable chart of sunlight with "counts" on the y-axis, but no love. However, the sunlight spectum image I have comes from a really neat page about researching (at Berkeley!) roofing tiles that reflect more light to reduce heat and energy use.)




It's just obvious that the incandescent has the fluorescent beat all to hell. At every wavelength the incandescent has more light. Fluorescents put on several coatings of different stuff to try to get a wider variety of light spikes, but after about three the coatings get too thick to be efficient anymore.

Light doesn't just matter to how an organism sees. Just a week ago at the work retreat someone mentioned that 70% of the light that a human brain concerns itself with doesn't go to the visual centers. There have been studies that found mutations in clock genes in people who get up at ridiculously early hours: normally, the first bright light you see in the morning re-sets your brain and that ticks down over the course of the day, counting out when you should sleep and wake again.

To me, it makes a lot of sense that the brain expects to get light on all the sun's wavelengths, and gets all screwed up if it's only getting 10 of them. Studies have found that people are more depressed and prone to act out under fluorescent lights. LCD screens are filters over fluorescent lights, and screw a lot of people up. Mice die faster. In looking through spectrum/lighting webpages, you'll find tons that talk about bird breeding, or snake thriving. Few seem to discuss that lighting bad for a mouse or a bird or a snake is bad for a human, too. Fluorescents are cheap.

So, going back a couple months, I thought I'd give compact fluorescents another try, just to see if they really had gotten better like my friends claimed. I stopped by Home Depot and got some brand-spanking-new compact fluorescents, in three different light flavors (based on "warmth", the degree-Kelvin measure of how blue the light is). I started with the lowest, "warm." Took those out after a day of use... Don't think you can slip sodium by me, assholes. If I wanted that "living under a bridge" look I could graffiti all the walls and pee in the corners, and it'd still be comfier. Orange! Grah!

Tried "cool white" next, and I've been there for a couple months. I can run 180 watt-equivalents of light instead of the pitiful 120 watts I could run before, and it's diffuse so that I have a better chance of reading stuff without shadows everywhere blocking, and it only costs 45 watts of energy so I can run the electric kettle at the same time without worrying about overloading circuits. And truly, the fluorescents have gotten better at not humming and not flickering. And yet...

The light is ashy.

I can feel my brain arguing with itself. "It's dark," say 95% of my light receptors. "No, seriously, there's light," says my visual cortex. "WTF pitch fucking black" say everything set up for light colors I'm just not getting... It's hard to tell whether my mood and pattern of living are affected, but I suspect they are.

I dunno. 120 watts really is pathetic.

Maybe if I try all three types of compact fluorescents at once, one in each bracket of the central fixture... Maybe I can finally get around to hanging the white Christmas lights all along the wall by my bed, and that would make up the difference in spectrum...

Upshot: politicians trying to ban incandescent bulbs are fucking smoking crack and oughtta be booted the fuck out of office. This is a health choice people need to be free to make for themselves.

Comments

[jon-leonard.livejournal.com]

There are a number of ways that the body is sensitive to light: You can feel it as heat, skin produces melanin in response to light, the pineal gland is light-sensitive, etc. But I'm not aware of any reason to suspect that these are particularly frequency-sensitive.

In other words, light-sensitive is interesting, but if the cells in question aren't known to distinguish between one spectrum and another, and there's no plausible physical mechanism why they would, then we shouldn't assume that the difference between incandescent and florescent would matter. It might be worth setting up the experiment, but I'd be shocked to find any spectrum sensitivity comparable in importance to what we see with the cones. (And that's pretty lossy.)

[zdashamber.livejournal.com]

Animals like rattlesnakes that track things thermally certainly have non-retinal cells that are sensitive to wavelength. Chlorophyll (http://en.wikipedia.org/wiki/Chlorophyll) has a distinct wavelength excitability. It is, in fact, implausible to suggest that cells receive just "light". Light exists as a group of wavelengths, and the mechanisms we're aware of for using light involve specific wavelengths inducing conformational changes in molecules within cells. Chlorophylls are from a group of similarly-shaped molecules called porphyrins (as are hemes) and both hemes and porphyrins have been found to regulate clock mechanisms (http://www-bmb.med.uth.tmc.edu/faculty/cheng-chi-lee.html) in humans.

[jon-leonard.livejournal.com]

Yes, it's different in other species. I said so in my original post...

I'm suggesting that for each of a fairly small (i.e. finite) number of significant interactions, the effect is that of an integral over frequency of the intensity times the response curve. Linear algebra then says that there's a spiky spectrum with the same effect. With a reasonably well chosen set of frequencies, they even all have positive amplitude.

A major problem with fluorescent lights is that they blatantly fail to be equivalent to a black-body when measured by the (standard) human color-vision response curves. [There are at least 8 different photoreceptor response curves in human eyes; Most are considered defective, thus the colorblind qualifier]

A significant property of the eye's color-receptors is that they have a comparatively narrow frequency response, which makes sense because they're evolved to discriminate color. The other mentioned effects (singly- and doubly- energizing chlorophyll interactions, rattlesnake thermal sense, human night vision, and for that matter all the other biological mechanisms I'm aware of) have wider response curves: They're less sensitive to the nature of the light spectrum than our vision.

My conjecture is that a spectrum with notable peaks in 4 or so places is sufficient to be indistinguishable by ordinary human mechanisms from an incandescent source. [Whether an infrared peak for warmth is useful is a separate question.]

[Non ordinary mechanisms include things like prisms, diffraction gratings, lab equipment, other species]

Do you have an experiment in mind to falsify that?

[zdashamber.livejournal.com]

Of course I have experiments in mind; they leap out at you when you consider the subject. A person could run a lab of PhDs based around tracking this stuff down... Cheng Chi Lee nearly is.

However, I'm content with having demonstrated reason to suspect that non-retinal human light responses are frequency-sensitive. I'd be interested to look at a paper or website about the frequency response of retinal cells, though, if you have one handy.

[jon-leonard.livejournal.com]

The best reference I have at hand is The Feynman Lectures on Physics, Volume 1, chapter 35 (it's about the physics of color vision). The spectral sensitivity curves are on page 35-9.

For an on-line reference, Wikipedia's article on the CIE color space (http://en.wikipedia.org/wiki/CIE_1931_color_space) looks (currently) pretty accurate, and describes the 1920 and 1931 experiments on indistinguishable color spectra.

Note the difference between sensitivity at a specific frequency and total response to different spectra; It's the latter that can be metameric. (And I still believe that non-black-body radiation can be equivalent in human response). At this point I think it's more that you don't believe me than that I'm being unclear...

[zdashamber.livejournal.com]

Dude, this is a discussion of science. Belief has no place in it. You're arguing that one spike for each of the known visual-pathway receptors should be enough to cover human response to light. I've been arguing from the original post you responded to onwards that the 70% of light information that doesn't go to the visual cortex is probably frequency-sensitive. This being scientific and all, I've provided a handful of links that back that hypothesis up.

We agree about just about everything, but I'm sad you're so stuck on the converting-light-into-vision stuff that you're blowing off the converting-light-into-timing-or-mood-or-other stuff. No doubt there is some number of spikes in the right frequencies and intensities to obviate all health effects from quantized light. The question is whether or not we consider systems of the body other than the visual system when guessing at these spikes.