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A PHYSICIST WRITES . . .
(March 2010)
Mrs S and I attend a weekly French class. For reasons I won’t go into right now, I was obliged to miss a few lessons, and last week (as I write) was my first time back. I’d been too busy even to think about the homework that I knew had been set. One of the instructions was: prepare a description of an object that’s special to you, which you can read out to the others for them to guess at.
We often play this game, except that usually our teacher hands out words on cards, and then calls on us to describe or define them on the spot. I like to start enigmatically and then give more obvious clues. Not that any of us are fluent French speakers! The trick, when stuck for a French word, is to mutter the English one at the teacher who then prompts you with the French, to keep you going.
Anyway, as her eye fell on me last week, I suddenly thought of something I could describe fairly easily — my Toyota, a 1997 Corolla as you may remember from previous columns. So: “Mon objet a quatre [muttered at the teacher: wings?] ailes. L’une est d’une couleur différent que les autres.” (Yes, you may remember too that one wing is sadly faded.)
“Je suis trés content de dire que l’accélérateur de mon objet [does not stick?] ne se coince pas, et [the brakes?] les freins marchent bien, [unlike?] pas comme quelques autres objets du même nom.” At which point, of course, there was a cry of “Toyota!” from some of the others.
This suggests that the company’s recent car-recall problems were in their minds as well as in mine. I have to admit though that all along, my main rather selfish thought has been that I’m glad my car is a dozen years old and not five or less, like all the models that were subject to recall. But now, to enable me to continue with this topic, I’ve been investigating how the Toyota story developed.
It seems to have started last autumn in the US, with one or more incidents of unrestrained floor-mats interfering with the accelerator pedal in Lexus cars (the luxury end of the Toyota range). Thousands of sets of ‘all-weather’ mats were recalled first, and then whole cars — in millions — for their mats to be replaced by thinner ones.
Then it became known that in several Toyota models (but again only in rare cases) accelerator pedals were sticking down without interference from a floor mat. Here we meet a significant difference between old cars like mine with throttle cables, and modern ones with computer control: the computer requires an electrical signal, rather than a tug from a cable, to tell it the position of the pedal and hence the intentions of the driver. So the modern pedal is simply a spring-loaded lever, directly connected to a electrical sensor. However, it does need to have some added friction (previously supplied by the cable and the rest of the mechanism), otherwise you wouldn’t be able to keep the pedal in a steady position as you drive.
It was the particular friction device attached to the accelerator in these Toyota models that came unstuck — or rather, just the opposite: the friction surfaces seized together (instead of sliding ‘smoothly’ past each other), though very rarely. The result was that millions more cars were recalled worldwide. The Toyota UK website has videos showing that the ‘fix’ was a relatively simple one, though I was slightly puzzled to see, as well, a written description of the problem that referred to surface tension, which is a property of liquid surfaces rather than solid ones!
Toyota’s troubles continued with a recall of 3rd-generation Prius cars, for an upgrade to the software controlling their anti-lock braking system. The problem, apparently, was that when the vehicle hit a bump or a pothole or a “low-grip surface” (is this a euphemism for ice, or what?), there was a change in how the brake pedal felt to the foot. The actual braking ability was unaffected, according to Toyota UK.
But then as I searched further my spine shivered (for a moment) to see that owners of Corollas had complained about their power steering ... however, this was confined to a model sold only in America, and it had not even become an official concern over there, so I relaxed again. But you can imagine that people in the Toyota company are far from relaxed, still — and many of their customers must also remain a little nervous — wondering if there are more scares to come.
Let’s change the subject to a different sort of scare. I’ll explain now (as the outcome is good news) why I had to miss some French classes. Visiting my GP last autumn, I said to him: perhaps while I’m here you could check out my water-flow problem, as you’ve done a couple of times before. This time he didn’t like what he found, and within days I was called to be tested at the Royal Berks Hospital in Reading. The diagnosis was early-stage (hence usually curable) prostate cancer.
The treatment option I chose was extraction of the offending item — by robot! This was done in January, and today (as I write) I have just been given a virtually definite all-clear. But my condition had been near to borderline, and I could so easily have put off asking for another year or more, with maybe a different outcome...
PC is the commonest male cancer, killing 10,000 annually. So just as I never miss an opportunity to wave the flag for advanced driving, now I lose no chance to say to men of a certain age (50+): if you have problems down below, don’t hesitate to see your GP.
Also, be aware that you are entitled to ask in any case for an annual blood test for PSA (prostate specific antigen), which is the ‘best’ simple way of detecting PC if it’s developing. However, official advice isn’t clear yet on whether you should request the test, because it’s not 100% accurate: it can produce false-positive results, as well as false negatives. Therefore the GP will need to explain its pros and cons and risks. Anyway, à votre bonne santé! Good health to you!
Peter Soul
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