1. Cooking
2. Inquiry
3. Application
You know, I’ve never really every put much thought into smoke detectors. They’re ubiquitous. They’re frequently obnoxious. But what do they do? Or: how do they work?
I. Cooking
Ms. S. was out and about; I decided to cook myself lunch while she was away … a lunch that, for the most part, would not interest her.
Last night I prepared about a third of a container (a container being about a pound) of extra firm tofu. I have reason(s) to doubt the effectiveness of “marinating” tofu, but it’s still a technique I employ, but last night I just sliced it and squeezed it, and then dry-fried it for a bit before then cooking it in a sauce/glaze (soy sauce, cider vinegar, mustard mainly), and the adding some oil toward the end for pan-frying it.
Yum.
That meant I had two more similarly sized servings, and today I decided to put one in the oven. Also last night I took the last of the button mushrooms I had — they were losing their fresh, firm, dry feeling — and marinated them in oil, vinegar, and various herbs (e.g. thyme); this afternoon I stuck them on a baking sheet and put them in the oven at about 370-400F. Then I lightly breaded the tofu — equal parts cornmeal and flour, a dash each of baking powder, salt, paprika, and cumin — and, applying a little non-stick spray, added it to the baking sheet about 20 minutes in. I flipped the slices 20-30 minutes later when I tossed the mushrooms, which were browning and shriveling nicely. On the range I caramelized the remaining half of a red onion I had and, then, when the time was right added about four ounces of turnip greens and some chicken broth.
When everything was about ready I plated the onion and greens, then de-oiled the tofu and plated it, and put the mushrooms under the broiler for a minute. That’s when, as I started to take them from the oven, that the smoke detector in the hallway a dozen or more feet away decided to go off.
It does not have a battery. It does not come off the wall easily. I pushed the button, I covered it, I closed the oven door. It stopped.
I returned to the kitchen. I turned off the oven, I turned on the fan over the range. And then the smoke detector went off again. And would not stop. Ms. S. was not home, which is good, as the smoke detector — which has gone off a few times before when I cooked steak and chicken — sends her into a bit of a fit (during which time she tries to get me to promise never to cook ‘X’ (whatever I’m cooking) again … and I decline). But there are neighbors. And my own ears and sanity. I had fans on, I had my hand over it. I applied pressure. I muffled the noise, and it would stop for a few seconds, and eventually start up again.
Eventually I got it turned more than half way around and it came away from the wall. Then I saw the wires leading into it and I pulled them out.
Silence.
II. Inquiry
And the question came to me a bit later, as I sat in the office enjoying my (a) greens, (b) caramelized onion, (c) breaded and roasted tofu, and (d) marinated and roasted mushrooms — and the smoke detector still rested impotent upon a kitchen counter — that I was not exactly sure how smoke detectors work, what they detected.
There’s never been any visible smoke when it’s gone off before; nor has there been anything that I or Ms. S. can smell. Candles do not set it off. I had also googled how to deal with a smoke detector that won’t shut off. Someone mentioned CO (carbon monoxide) detection.
Smoke detectors — so an eHow article and WikiPedia — tend to ‘detect’ one of several things one of several ways:
- ionization to pick up smoke particles: this is where radioactive isotopes come in, as they give off ionizing radiation that (a) help conduct an electric current unless (b) smoke particles bind to the radiation (alpha particles in this case), disrupting the current and causing the alarm to go on
- optical: sort of like a motion sensor in movies, a laser or such is aimed at a optical sensor, but if smoke particles get in the way they disrupt the signal and set off the alarm
- air-sampling: not dissimilar to the optical detector, but they sample over a greater area, rather than in just one location
- carbon monoxide sampling: these are better for detecting toxic levels of CO, but are less effective at sensing smoke or fires
The ionization smoke detectors were the ones — usually based on Americium-241 — that I was already sort of familiar with. The others made sense in terms of technology and science, but I wasn’t previously aware of them. And the WikiPedia article on smoke detectors further provided an interesting history of their (partially accidental) development … and eventual ubiquity. It’s sort of weird to think that early in my childhood they were not that common.
III. Application
Life is full of poetic serendipity.
The “poetic” should not be necessary; it should be redundant in a way … or at least superfluous. But I wish to counteract any implication or inference of ‘deeper meaning’ … something more akin to ‘synchronicity.’
But I digress.
Later in the afternoon I decided to visit one of my favorite blogs, Pharyngula, and what should greet me but a post (a) mocking Ken Ham, (b) featuring Bill Nye (the science guy … yay!), and considering, among other things, smoke detectors.
See also: “Hammy gets it wrong, again”
In summary: standard smoke detectors are ionization smoke detectors, which means they rely not just on radioactive isotopes, but on the accurate measurement of the half-lives of isotopes, which means they rely on an accurate-enough understanding and theory of radioactivity and matter. Smoke detectors were just an example linked to a broader understanding of (a) radioactive decay and by extension (b) radiometric dating.
Science: It works.™
IV. Appendix
- for dinner, more tofu and more turnip greens and another onion, but this time all in a skillet as Ms. S. and I watched ‘The X-Files’ (season 1, “Ghost in the Machine”).
- ‘Top Chef’ … ah, Carla, we barely knew you, and we appreciated how you got on Stefan’s nerves. Chrissy? We didn’t know you … and a soggy salad will get anyone sent home. Since I had mushrooms for lunch, as I was a bit pumped by Kirsten’s win for mushrooms. See The A.V. Club for a great review.
- I’ve stuck Ms. S. with a notion, one she cannot un-see: Emeril Lagasse is a Sontaran. See also: Emeril Lagasse: Palazzo Las Vegas Grand Opening Arrivals and The Sontaran Strategem.
- we only have a couple more episodes of ‘Oz.’ Tobias is back in prison … it was predictable but still sad. I do love how season 6 is wrapping up storylines.
- end of the month … all bills paid.
- it’s hard to type with a cat on your lap … but she refuses to sleep anywhere else, and I’m too much a softy to evict her.
