Coincidences occur by chance far more often than we think plausible. It is very common for we mortals to overestimate the randomness of random, if you see what I mean. When people are asked to write a stream of random numbers they generally write down fewer repeating numbers (e.g. a six immediately followed by another six) than occur in a typical real random sequence. Most people too often chose the next number to be deliberately different from the previous one. This is because people think of having numbers repeating in a random sequence as a coincidence and underestimate its likelihood. Such “coincidence” groupings of numbers happen by chance far more often than people think.

It is the same with chance meetings. You are more likely to bump into someone you know at a foreign airport than you might imagine – purely by chance. The human mind tends to see patterns where none exist. Our brains evolved such a foible because pattern matching is useful when trying to discern the pattern of a predator hiding in long grass. A false alarm is much less costly than * not* spotting that sneaky beast with huge teeth and an appetite to match.

That is why we see faces in curtains and clouds and why many of us believe that coincidences are somehow supernatural when they happen to us. Once a fortnight on average someone somewhere in Britain has a dreams that their best friend died, only to learn the next day that it really did happen. This is purely by chance. There are millions of dreams dreamt each night, and many deaths each day. Combine the two and you see that such coincidences are inevitable by chance alone. But if it happened to YOU, what would be your interpretation of such a freaky happening? Would you consider it a meaningless chance happening or a tragic premonition? Someone experiences that every fortnight or so.

Back to the Digital Clock Coincidence! One morning an email landed in my metaphorical lap that contained this riddle:

“I was wondering if maybe you can give me an idea of why, every time I look at the digital clock, I always see for example 12:34 as in 1 2 3 4 , also 13:13 or 15:15 , 11:11 and so on. Is there any coincidence or are the numbers significant in anyway or am I totally just reacting over nothing!”

It’s a great question! (I remember being obsessed with the display of my digital watch when I was a kid). One possibility is that a pattern (like 11:11) is always more memorable than a non-pattern (like 14:53). So we end up cumulatively remembering the patterns and forgetting the non-patterns and over time we think to ourselves how weird it is that we tend to see patterns all the time!

There may be another effect here too. I conjecture that if you look at the clock at random then the digits are far more likely to contain a pattern then we imagine. This is because a higher proportion of possible combinations of times contain a pattern than we think. This effect is magnified because for digital time displays low digits are much more common than high numbers. (Hours digits only count up to 23 and minutes digits only count to 59). Indeed this effect is borne out by the examples in that email. Notice how in all of the examples – **12:34**, **13:13**, **15:15**, **11;11** – the digits are small: there are many 1’s but not a single 6, 7, 8 or 9. If most of the time the digital display features only small digits, then patterns are much more likely to occur.

There could be an even weirder effect at play here. We have many body clocks of different shapes and sizes, ranging from timing circuits within our brains to molecular clocks in each cell of our bodies. There is at least one autistic person known to science that can tell you the time accurate to *within a second*, let alone a minute! So it is possible the brain can decipher time better than we think, and in a few of us, the brain might subconsciously trigger a peek at a clock at exactly the “right” moment. to see a “coincidence”.

Food for thought!