Saturday, 21 January 2012

Is 193 prime and does it matter?

Sometimes I worry about myself.  Only sometimes.

The other morning, it was just before 7am and I found myself in the changing room at a health club.  It wasn't the fact that I was at there at such a stupid hour of the day which worried me, it was what happened next.

I was standing in the third bay of lockers, with the higher numbers, and I happened to be standing in front of locker 193.  And then it occurred to me that I am usually at the lockers with lower numbers, and instinctively I always use a locker which is a prime number.  This is easy when you're standing near the first 20 lockers, but in that second, rational thought deserted me, and I realised that I could only use the locker if 193 was prime.

So there I was, standing with a pound coin in my hand trying to work out at 6.50am whether 193 is prime.  It didn't take me long to work out that it is prime, and I made it into my session on time for a 7am start.  I knew you'd be pleased.

Now - just to be clear - there may be those who think I have made up this story for comic effect.  I offer two objections to that notional.  Firstly, I assert that the story is absolutely true.  Secondly, I assert that there is no comic effect present at all.


  1. I, for one, believe you.

    My alarm clock is set at 7:09 for weekdays as I prefer to wake on a prime if it can be helped.

    I am disturbed that you were at the gym at that time though.

    1. How long is the delay on the snooze on your alarm clock? You should set it at such a time that both the original alarm time, and the time after the first snooze, are both prime...