The Right Time

I’m quite fussy about the time.

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These are three of the clocks in my house. If you click on the image to enlarge it you’ll notice that they all show exactly the same time, to the second.

In the Cumbrian countryside there is a 17kW 60kHz radio transmitter operated by the National Physical Laboratory connected to three caesium fountain atomic clocks that constantly broadcasts the current time and date. Once a day, at night for some odd reason, each of the clocks in my house synchronises itself with the broadcast time signal, keeping them accurate to 1 second in 1000 years. My watch does the same thing.

Recently one of my other clocks fell off the wall and broke, so I took that opportunity to take it apart.

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This is the part that drives the hands, a highly accurate stepper motor.

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But this is the true heart of the clock: the radio receiver and the 60kHz antenna. The ribbon wire to the left of the image carries information from the receiver to the clock’s motors.

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You can just about make out the tiny radio crystal in the bottom right-hand corner of the circuit board.

On calculators

The Casio fx-992s is, without a doubt, my favourite calculator.

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I’ve had my fx-992s since I did my GCSEs and it’s served me very well. I own three – the original (shown on the left), the backup (shown on the right) and the backup-backup (not shown). I try to avoid having all three in the same place in case of catastrophic calculator loss.

I like the fx-992s because it doesn’t have any of the fancy, difficult to use “functions” that I see in my pupils’ calculators: it doesn’t do surds, it doesn’t give every answer as a fraction or require you to use Natural Textbook Display and it doesn’t have a weird cursor-controller joysticky thing.

Most of the pupils I teach can’t use their calculator properly – the calculator companies’ efforts to make calculators easy to use have done exactly the opposite.

Deaths from “Swine Flu” in perspective

If I had £1 for every person that died of so-called “swine flu” between 24th April and 6th May I would have £31 and would be able to buy a fairly decent meal.
My stack of coins would be just under ten centimetres tall.

If I had £1 for every person that died of tuberculosis between 24th April and 6th May I would have £63,066 and would be able to buy a fairly decent two-bedroom house in Liverpool.
My stack of coins would be just under 200 metres tall.

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