Merry Christmas Eve

I really did want not to be grumpy over Christmas but on Christmas Eve morning I read that Ofqual, the ‘examination watchdog’ (some watchdog), are going to drop the requirement for a practical examination for science A-levels. They have the support, apparently, of our scientifically illiterate government. Will they never learn?
Things got better after that. We went for a walk along the Avon into Bristol and had lunch at the Nova Scotia, including a sausage and egg sandwich (keep it up, you statins). Back home and H beat me at dominoes (threes and fives) yet again, then an email and pictures from my son and family in Australia – they are camping over Christmas. Finally, we watched Professor Branestawm on TV. I wonder what he would have thought about getting rid of practical examinations?
A Merry Christmas to all.

I Don’t Believe It!

A hero of any grumpy old person in the UK is Victor Meldrew, a character in the BBC TV series “One Foot in the Grave”. Victor was recently retired and was having trouble dealing with modern, ‘efficient’ ways of doing things. His usual response when thwarted was “I don’t believe it!”. I had my own ‘I don’t believe it’ moment the other day when confronted by a computer program containing a feature which, although useful in some cases, could not be turned off through the user interface.

Adobe Acrobat (the full program, not Acrobat Reader) is a very useful program. I have to deal with PDF files often and find it indispensable for manipulating, commenting on and joining PDF files. The latest versions have a useful feature: the ability to recognise text on a scanned image. But you don’t always want to do that. I am currently reviewing a large technical document which contains a lot of figures. When I try to scroll through the document, it keeps on locking up while it tries to extract text from the figures. So I decided to turn off that feature temporarily.

Having spent ages exploring every nook and cranny of the user interface I still could not find how to do it. I tried the usual search engine – lots of information on how to use the feature but nothing on how to turn it off until the second page of search results, in a link to a user forum. It appears that the recognition feature is the result of US legislation on accessibility, and that legislation requires that the feature cannot be turned off (why?). There is a solution: shut down Acrobat, go into the program files and dig down until you find a file called Accessibility.api in the plug-ins folder. Rename that file to something like Accessibility.api.off, restart Acrobat and the recognition feature is no longer there until you restore the name of the accessibility file. At least I hope so, I haven’t tried that yet.

I just don’t believe that it is acceptable to include a feature which, while useful, you might just want to turn off and then not provide a means to achieve that in the user interface. It’s things like that which make me shout at the screen, thereby adding to everyone’s view of me as a grumpy old man.

PS Actually, there are some very positive things about being grumpy. I may return to them in a later post

Stretching the Analogy

I really like the image created by the American theoretical physicist John Archibald Wheeler (1911-2008) when he said “As our island of knowledge grows, so does the shore of our ignorance“. Being a physicist, I suspect he had in mind Newton “like a boy playing on the sea-shore … whilst the great ocean of truth lay all undiscovered before me“. It is a good image because it reminds us that, however much we discover about the universe, we are still confronted by further ignorance.

It’s not quite as bad as that because, pushing the analogy a bit, at least that “shore of ignorance” does help us to define the scope of that ignorance. Maybe the ‘known unknowns’ lie just off that shore, although I am sure that Donald Rumsfeld did not have science in mind when he used that expression.

It occurs to me that, if the island of knowledge is roughly circular, then the shoreline will increase in direct proportion to the size, while the area increases as the square of the size. So our knowledge will increase faster than the shoreline of our ignorance. Mind you, that only works if the island is roughly circular. If it is long and thin and we are extending it only at its thin ends, then area and perimeter both increase in the same proportion. Maybe that is a warning not to pursue just one line of investigation; we need to look in all directions.

Frankly, this is stretching an analogy to breaking point. But, like all analogies, stretching it a little bit does make you think.

Lessons from a Door Bell

My wireless activated, electronic door bell stopped working recently. I changed the battery in the bell push, tried to clean up contacts, scratched my head and gave up. It had died. So I bought a new one. When installed, the new one went bing-bong. I read the instructions and found I could get other tunes but I couldn’t be arsed so I gave up and decided to live with bing-bong.

That reminded me of a time many (say 50+) years ago when my parents got a man in to install a bing-bong door bell. It was a box on the wall with two tubular chimes hanging down. Being a curious (or irritating) child I took the front off the box to see how it worked. It was a simple electro-mechanical device. There was a striker which could move horizontally but which was held off the two chimes by a spring. The striker was inside a solenoid on one side and when the bell button was pushed the striker was pulled into the solenoid and hit the ‘bing’ chime. When the bell button was released the striker was pulled back by the spring, overshot and hit the ‘bong’ chime.

Why am I bothering to write all this? Well, I learnt a lot from taking the cover off that door bell. I could see how it worked. I learnt a bit about how a solenoid works. I began to appreciate something about spring rates: the spring has to be weak enough to let the striker be pulled into the solenoid and hit the ‘bing’ chime but strong enough to pull it off the chime so as not to deaden the sound, and weak enough so the striker can overshoot and hit the ‘bong’ chime before returning to its rest position.

That’s a lot of learning from a simple device and remember that was all obvious from a simple inspection. I’ve got a rough idea how my new electronic door bell works but that’s not obvious, and I could not mend it when it went wrong.

Here’s the grumpy bit: the new door bell is fine and does what it supposed to do. But have we lost something in moving away from a simple electro-mechanical device?