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A PHYSICIST WRITES . . .
It’s been a unusual summer! On the road, for example, I’m sure motorists have been hooting at me more, or otherwise showing annoyance, for simply keeping to the speed limit or holding the correct lane for my intended route. I put it down to the (occasional) heat, and the Lipstick Red of my old Corolla which, even though fading, must be quite distinctive now among all the fashionable silvers, greys and blacks. I’m almost looking forward to changing one day to a car that’s a less coloured rag to bullish drivers.
In August, Mrs S and I went to the cinema to see a superb performance of Mozart's The Marriage of Figaro, relayed live from Glyndebourne. By the way, did you know that many cinemas now offer selections of operas, ballets, plays and other events, coming direct from national and international stages? It’s better than being in the front row of the stalls! But unless you search the websites, you’re unlikely to find out about these screenings. Here are some links:
On with my story: before Figaro started we were shown a short film about the opera house, including a proud mention of its new wind turbine which is supposedly able to provide all the electricity needed on-site (given the wind, of course). The commentary then continued: “The Glyndebourne Festival, which runs for three and a half months, uses roughly 800,000 kilowatts of power.” I nearly fell off my seat.
Later at home I found the same film on the Glyndebourne website and checked what I had heard. I then emailed them: “Your claimed usage is equivalent to running 800,000 one-bar electric fires all summer, and must be taking all the output of the nearest power station. And I fear that the wind turbine will not make much of a dent in your electricity bill, which I estimate at £200m for the Festival ... Ah: I see from data elsewhere on your website that you should have said roughly 800,000 kilowatt-hours of energy (the traditional ‘units of electricity’), which is about 1/2500 of the energy consumption that you were implying in the film.”
OK, scientific quantities are not always easy to grasp, especially when an unnecessarily long number (800,000) is combined with a prefix (kilo) which itself represents a large number (1000). If the quantity in the script had been simplified to “800 megawatts of power”, I think someone might have queried it sooner! But we are all consumers of electricity, so it’s good to try and remember firstly that power is the rate at which we use energy, and secondly that a kilowatt-hour (kWh) is the amount of energy you consume if you do it at a power-rate of 1 kW for one hour, or at 2 kW for half an hour, and so on. (Don’t blame physicists for this kWh unit of energy: our unit is the joule, which we find much easier to deal with.)
Would you like to try a comprehension test? Go back one and a bit paragraphs (and then one more): can you see where I got my figure of 2500 from? The explanation is just below. Anyway, two weeks after my email to Glyndebourne, I received a reply: “Thank you for drawing our attention to the mistake. We have re-recorded the line, and the corrected film is on our website.” And very neatly done it was too. A minor triumph for physics!
[They had claimed a power consumption of 800,000 kW over the 3½ months. My correction was equivalent to 800,000 kW for an hour (though in reality, of course, the energy use was spread over the summer). So I worked out the number of hours in 3½ months: about 2500.]
Now for a traveller’s tale which, extraordinarily, involves all the five ladies in my (longish) life, not to mention a few teams of basket-ball players on wheels. On the last Friday of August, Mrs S and I set out for the south of France to stay with my sister. We arrived at London City Airport, and got out our passports. I opened mine – to be met by the face of my mother.
Worse: when she had the photo taken some years ago, she was told to look serious. The effect was like a parental ticking-off. I won’t bore you with an explanation of how the passports became mixed up. When I had regained composure, we discussed what to do. In the end I rebooked for Sunday evening (the next direct flight) and said goodbye to Mrs S, bravely travelling on.
As it happened, our daughter and her friend were already booked on that next flight, to join us. When I got home I phoned to tell her the story. She called back: would I now like to spend Sunday at the Paralympics with her and her mother, taking her friend’s ticket? He was happy to give it up, and anyway they had already visited the Games a few times.
I protested of course, but not hard enough. And I must say it was a thrilling day. Our tickets were for the noisy wheelchair-basketball arena, where you felt the combatants would have won any match against regular players. We also looked in on goal-ball: what a contrast! The spectators had to be completely silent during play, so that the (unsighted) players could hear the special noise-generating ball. In fact, each pause in the action ended with soothing music to quieten us all down.
It was only a short taxi ride to the airport in the evening, conveniently, and the rest of the holiday went smoothly ... except that as I eased myself on to the hammock beside the swimming-pool, one of its ropes broke. OK, you may laugh, as I suffered only a bruised coccyx and thumb. The hammock has now been fitted with stronger rope, and they are jesting about borrowing a cow from the farm next door, to test it properly.
But going back to the wheelchair basketball: the game is policed by three referees stationed around the ten players. Regularly one of the latter would topple over (staying strapped into the chair). If they couldn’t right themselves, two team-mates would help them. However, I noticed that the (male) referees never assisted, not even when the victim was upended right next to them, in a ladies’ match! Was such gallantry forbidden? I’ve just now found the Official Wheelchair Basketball Rules online, but they don’t forbid a ref from doing the decent thing – as any policeman would do, for example, if you were in similar trouble on the road.
I might mention that some of the wheelchair rules would be unacceptable in the Highway Code: “If each hand is on the wheel, it is legal to raise the rear wheels off the ground ... no steering devices, brakes or gears are allowed ... if one person legally crosses the path of another, the latter is responsible for any contact ... the distance needed to stop is proportional to the speed.” As drivers should know, stopping distance (once you’ve thought about it and started stopping) is proportional to the square of the speed.
Enough of this summer’s entertainment. I’ll just add a footnote to my footnote last time on wall-sockets in France: not only are these permitted in bathrooms (which they certainly aren’t in the UK), but also you are quite likely to find one installed right next to the light switch just inside the door. I’ve noticed this elsewhere on the continent too. You might feel safer relying on a torch instead of reaching round for the switch.
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