OddThinking

In hindsight, the clock was hideous. Royal blue and white perspex, with a brass pendulum, it was probably the height of fashion when it was purchased in the mid-seventies.

But by the mid-nineties, when it was finally retired from its central position on the dining room wall, it appearance had fallen out of favour.

It had character – not so much its appearance, as its random noises. Every now and again its regular tick-tock beat would be accompanied by a peculiar whirrrrrrrrrr-click!

I am guessing that some of its cogs had worn down outside their tolerances or some pin had become bent, and under just the right conditions, a cog would no longer be constrained by beat of the pendulum. A spring would drive mechanism backwards and forwards at a high rate, causing the whir, until the pieces meshed together again with a click, and the regular beat would resume.

The hands didn’t budge noticeably during this process, and any disruption to the timekeeping was hidden by the fact that the pendulum had been adjusted to keep moderately good time.

The noise wasn’t irritating; my family had become used to it, and it didn’t impinge on our consciousness any more.

Until the PhD students came to visit.

My father, Joe, had invited a few biology students around for a drink, and as they sat in the living room, they heard the noise from the clock and became interested.

We explained that it occurred randomly, about once every hour or two, sometimes shorter, sometimes longer.

Later, it occurred again, and the students became more interested. They wanted to know exactly when it occurred.

We had heard the noise thousands of times over the two decades of the clock’s life and had never noticed any rhythm to it. This was before Chaos Theory had become a household word, but even then I understood that it didn’t take the full complexity of a clock mechanism and the randomness of mechanical tolerances for the noise to become unpredictable without hundreds of measurements. We tried to explain that they would never be able to tell.

That didn’t phase them – someone grabbed some paper and jotted down the time.

It was only about eight minutes later before they exclaimed suddenly. The clock had whirred again, but I hadn’t noticed. They recorded the time to within a few seconds.

This just reinforced to my father and I how random it was. Normally, it would be at least 45 minutes between whirrs, but that time it was only eight minutes. It probably wouldn’t occur for another two hours now.

Eight minutes and 23 seconds later, they shouted with glee. The clock had whirred again. Weird. It didn’t normally happen so frequently.

Eight minutes and 22 seconds later, one of the students pointed dramatically at the clock. On cue, one second later, the clock went whirrrrrrrrrr-click!

My father and I were both incredulous – in just over 30 minutes, they had found a regular pattern that we had never noticed. The main reason seemed to be we just didn’t even sense the noise any more, only hearing it once every hour rather than once every eight minutes and 23 seconds.

Their sampling continued during the afternoon, reinforcing the precise regularity of the fault. (Although, there was more than one one measurement of 16 minutes and 46 seconds, suggesting that they, too, slowly grew oblivious to it.)

I don’t really have a conclusion to this story. I could probably make some philosophical point here about the power of having a fresh set of eyes, the analytical abilities of scientists with a new puzzle, how we ignore the familiar, but that wasn’t why I wrote this. I just remembered the ugly old clock today, that’s all.