Δαφνη Ευτυχια Αρθουρος

"This is adding a tax for the sake of a tax. It proves what I've been saying all along, that the Democrats want to tax the poop out of us." -- California state senator Tom McClintock, about a tax on disposable diapers

My circadian patterns have been randomized by this cold. I'm not sure whether I'll make it to rehearsal tonight -- if I do, maybe I should wear a mask, and I certainly won't be playing woodwinds, but it may be moot anyhow because the person I expected to ride with is having transportation difficulties of her own. I'm uncomfortable, annoyed and frequently sleepy. It's not a monster as colds go, partly because my "get over it faster" tactics, which don't seem to be making it faster, do seem to be helping with symptom-management, but it's still a nuisance.

I've found a new game: playing with the cat's pupils. Perrine was in a "want to pounce on things" mood, and I was sleepy, and I moved my hand under the blanket and she tracked the motion ... so far pretty normal person-playing-with-cat stuff ... but then I noticed that when I moved in certain ways, her pupils suddenly got Really Huge for a moment, and contracted again soon afterwards. So I sat there poking my finger out and hiding it again, watching her pupils dilate and contract and dilate and contract, and being disproportionately amused.

It did get me thinking about the phenomenon from a biological perspective though, as well. When something interesting happens in hunting mode, the pupils open up by several f-stops, which means much more light is entering the eye, which kindasorta makes sense ... unless the pupils were at the right size to be comfortable in the current environment to begin with, in which case her world would suddenly go way too bright, wouldn't it? And the reduced depth-of-field means fewer things are in focus ... or maybe that's the point, to isolate the thing that moved in her field of view from the background? Or maybe her pupils weren't at the "right" size for the amount of light in the room, but narrowed down for hunting mode to provide greater depth-of-field for motion detectin, and opened up to enough-light-to-see-clearly to examine the motion once it was detected? I'm going to have to start noting the size of her pupils in various moods and lighting conditions to establish "comfortable normal" as a function of brightness, compare that to what her eyes do in hunting/play mode, run some depth-of-field experiments on my own eyes ... and I'll still wonder whether differences between feline and human retinas, or differences in how our brians process visual stimuli, mean that the perceptual effects for her are completely different from what I calculate. Maybe cat eyes handle overbrightness better than human ones? (I've never seen a cat shake its head or look uncomfortable after a flash photograph, but I've seen plenty of humans complain about spots in front of their eyes.)

Hmm. It occurs to me that there's someone I might be able to ask for a layman's version of the feline visual system. In the meantime, does anyone here happen to know off the top of his or her head the distance from lens to retina in a cat's eye? (That is, the effective focal length of the lens of a cat's eye when focused at infinity? I think there was some dicussion of the optical properties of human eyes on the Pentax-Discuss Mailing List a year or so ago, if I can find it, and I'm not sure mammal eyes can be thought of as having a single focal length (because they change shape to focus instead of changing distance from the retina) ... if that half-remembered detail is right, there might be more math involved.

I'm not sure I want to figure out what to plug into a search engine to find the information I need about the feline visual system right now, or that I have the attention span to wade through the results looking for the pages I can actually understand with my lack-of-background in neurology (and I've got more urgent things to do when I feel alert enough anyhow), but it'll remain an interesting back-burner question for a while. (Explanations and URLs cheerfully accepted though. If someone has a pointer to a page that addresses exactly this phenomenon, that'd be cool-and-a-half.) Right now I think it's time for Yet Another Mug Of Decaf Earl Grey, and then I'll fall asleep watching television shows from the end of October that I'm just getting around to.

Hmm. I wonder whether I should revisit that long tangent about lenses sometime when I'm alert and focussed and better able to organize my thoughts, and put it elsewhere on the web. Then again, it's probably already been done several places by people who actually know more about the subject.

EDIT: I just read this back after I posted it and realized I am such a geek.

Grrrrrr. Today's mail brought a citation from the Baltimore Department of Public Works, for having my trash out on the wrong day. Which I didn't do.

As if it's not bad enough that I have to move my car to the other side of the street twice a week for street cleaning (which wouldn't be as much of a pain as I make it sound, if it weren't for the fact that I have to make sure to move it back again as soon as the street cleaning restriction ends, because of rush hour restrictions on the far side of the street, so I can't afford to fall asleep on Tuesday or Friday afternoons regardless of how tired I am) but they only actually drive the street cleaning machine down my side of the street about twice a month on average. And that they almost never pick up the newspapers on newspaper recycling day, and only pick up the bottle and can recycling about three fourths of the time. Now I'm getting fined for "my" trash, when I'm the only person on my side of the street who actually uses a trash can.

[pout] Life is so unfair. [sulk]