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Feedback: Feedback can be dangerous

Why smokers need quantum superpowers, the not-so-smart state, LEO just doesn't add up, and more

Feedback can be dangerous

FEEDBACK is grateful to Miles Maxted for the lovely photograph of an enamelled metal sign, now adorning our wall: “Beware of feed back.” Apparently, it fell from an 11,000 volt electrical line in Auckland, New Zealand.

Adding to our discussion of the many uses of the term “feedback” (24/31 December 2011), he says its purpose is to remind those working on the lines “that disconnecting a community’s set of electrical appliances opens one to experiencing the full effects of collapsing fields” – that is, to voltages generated on the apparently disconnected wire when devices such as electric motors are abruptly cut off. So that’s another reminder that “not all feedback is beneficial”.

It had to happen. Ted Webber sends a scan of page I8 of the Developer’s Reference Guide to Small Basic which contains only the words: “This page intentionally not left blank”

Airport bends to our power

THE power of Feedback manifests itself in other ways, too. On 4 July 2009, we reported a sign at that lovely gateway to London, Heathrow Airport’s Terminal 1. It read: “It is against the law to smoke either within or outside this building.” Our source fled to a wasteland of slip roads and overhead walkways – arguably, neither within nor outside the building.

Returning to London last month, he visited the spot again, only to find a shiny shelter for the devotees of the evil weed lurking beneath the same bridge. Back in the building, the sign was nowhere to be seen.

No smoking anywhere

CONGRATULATIONS to the Feedback reader who must be working on the Terminal 1 rebuild (above). We hope they will persuade colleagues at Glasgow Airport to produce instructions aimed at mere Newtonian mortals as opposed to those with quantum superpowers. Reader John Slaughter recently found a similar sign there that read: “It is an offence to smoke or permit anyone to smoke either within or outside this building.”

How to make pseudoephedrine

A COLLEAGUE with a head cold visited a London pharmacist to ask for a decongestant to ease the pressure pain he was expecting on a forthcoming transatlantic flight. He received the very direct response: “The wake-up or the go-to-sleep version?” Pseudoephedrine is the “wake-up” option and it has become hard to obtain in the US.

Organic chemists are undeterred. A recently published paper notes: “A quick search of several neighborhoods of the US revealed that while pseudoephedrine is difficult to obtain, N-methylamphetamine can be procured at almost any time on short notice and in quantities sufficient for synthesis of useful amounts of the desired material.”

The reader who alerted us to this paper wishes to remain anonymous. The paper gives credit to the method described by Julian Blagg and Stephen G. Davies (). Its authors’ intent may be deduced from pseudoephedrine’s use in the manufacture of methylamphetamine, also known as crystal meth; their names being listed as “O. Hai and I. B. Hakkenshit”; and from appearing in the Journal of Apocryphal Chemistry.

Redundant prohibition

WHILE on holiday from her native Germany, Barbara Wueringer spotted a sign in a park in Cairns, Queensland, Australia, saying: “Illegal use of the land is prohibited.” Nearby car number plates bore the words: “Queensland – the smart state.”

She finds it difficult to reconcile the two messages. “English is not my first language,” Barbara writes fluently, “but I thought that illegal use of something implied that it was prohibited.”

Feedback wonders whether her confusion might be to do with German civil law’s emphasis on the written law. The English (and Australian) common law system, depending as it does on the question “What did the judge have for breakfast?”, can involve more ambiguity.

LEO’s descendants multiply errors

FINALLY, Allan Reese sends his application for membership of the Society for the Promotion of Numerate Proofreading (6 August 2011). He supports it with a story from London’s Daily Telegraph on the 50th anniversary of the LEO I, the general-purpose business computer developed by J. Lyons & Co, which owned tea shops throughout the UK in the 1950s.

A factoid box in the article proclaims that the clock speed of the LEO was 0.5 MHz and that of an iPhone 4S model is 800 MHz. It goes on to explain that “the iPhone is faster by a factor of 16,000”.

It is possible, though, that it is not just this number that is too high. Feedback and Allan both consider a speed of 0.5 MHz rather large for a system built with thermionic valves. We find the figure repeated dozens of times in very similar phrasing in numerous internet sites, such as the . Could it be that a mistyped number has proliferated wildly thanks to LEO’s successors?

We do wonder, too, why no one at the Daily Telegraph used one of those new-fangled “electronic brain” thingies to check the arithmetic in their comparison. They may wonder the same when a sarcastic gremlin inserts an error into this very page…

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