Monday, May 24, 2004

Had to blog this [assuming the link works - you might need a free log-on).

Teachers' exam boredom: the ugly truth. Hmm, maybe I went to a boring school, but I don't remember noticing the teachers doing half of this. Admittedly a fair number of invigilators take books or marking in with them - though technically such distractions were not allowed. But it's not like any of us would cheat [much].

They definitely played the paper game though. I think the maths department also came up with a version of battleships. And there was some Fox and Geese or pacman-esque game, whereby the invigilators moved one step at a time round the grid of desks (the catchers had to response to pupils, the target didn't).

Ok, so this sounds like quite a poor exam environment now, but as long as it kept the invigilators from coming up behind you, reading your answers and tutting over your shoulder, it was good. The worst one, was an English teacher who spent the entirety of a 3 hour exam switching lights on and off. I think she was trying to adapt the lighting to cope with the rapidly changing weather and light levels outside. However this noble sentiment goes somewhat awry when the lights in question are aged fluorescent tubes. Turn them on, and they blink, flicker, strobe, hum, plink, buzz, and occasionally go bang. Most of the circuits were in parallel, so one tube flickering caused the others in that circuit to pulse in antiphase[1]. It didn't help the woman couldn't remember which switch controlled which lights. So just as one set had settled she decides she needs to turn on another set, and turns the first off and back on again in the process. Basically, due to the overhead cacophony, and erratic lighting, the exam felt like there was a lightsaber[2] duel going on above us.

[1] Apparently that's not a word. I meant the light's activities were synchronised so that as one dimmed the others brightened, and vice versa [so that's 180o from the original for those used to putting it like that, in which case you'll already have guessed that]. Which when the resistance of, and current flowing through each is erratic leads to massive interference patterns on the other bulbs, resulting in an apparently chaotic lighting of each bulb.

[2] Is that lightsaber or lightsabre? Word claims sabre, I say saber. According to Google, 10 times more references to the –er spelling than –re.

Congratulations by the way, to whoever it was at the Max Planck Society who managed to be the 1,500th hit here. Even if all he wanted was a certain Keane song. And I'm carefully not noticing the stats on various other blogs, though in one case he's probably got his parents to thank for half of them [and he started later than I did, though in fairness, he can write better than I can]. Whereas the only distinctive bit of the name here seems to a Texasism [and only a Texasism. Maybe I should have used my real name, but it's even less distinctive, and my only namesake of which I know is a obscure television presenter].

Looking at the Max Planck site: what's a boson? [particle physics, not the guy in charge of rigging]. But "fermions" sound like it ought to be "we are shutting" in French.

Apparently a boson is a gregarious particle, the particles in question ranging from photons to alpha particles. Am I allowed to admit I'm lost? I know what photons and alpha particles are, and I can cope with the concept of that some particles are more likely to cluster than others. But how do they do it, and to a lesser extent, why do they do it? I don't know, I can't see why, and the press release doesn't enlighten me [and the fact that under certain conditions the states can switch doesn't help].

But then the phrase "...which is a measure of how fast they spin around themselves" makes me think of a dog chasing its own tail, so I'm obviously not on the right wavelength.

So a boson has quantised spin, and groups of otherwise identical bosons have uniform spin at a certain level? Right. Fermions have a spin "equal to an integer plus an extra half". Er...? If it's 0.5 more then surely it's still quantised, and it's just the quanta are on the wrong scale? 0.5, 1.5, 2.5 is no less uniform than 1, 2, 3. Except apparently the plus-a-half ones cannot occupy the same quantum state as otherwise identical fermions [why? remind me to annoy my brother by asking him].

Apparently they managed to make bosons act like fermions in two out of three planes. Which is great, if only I could figure out why they need to [3], and how they did it.

[3] Other than the "because it's there" answer.

Sorry for the crap writing of that bit, but it was me making notes as I try to figure out something I didn't understand, and still don't quite get.

Oh and to the person searching for mispelt versus misspelled - "Misspelled" is the American spelling. "Misspelt" is apparently the correct English spelling. And "mispelt" looks better [languages evolve, so why can't a superfluous "s" be lost along the way? Because MS Word, with UK spelling switched on, only recognises the longest version].

Sorry, I'm a bit distracted at the mo, hence the bittiness, so I'll stop now.


PS. Sheesh, Word is abysmal at scientific words. Most of the time I have to check which variant gives more results in Google [I was sure the word was "quantitised" not "quantised", but with only 17 results versus 14k, I'm obviously wrong (600 to 228k for the respective "z" versions)].

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