Last night I watched The Weakest Link and was surprised. It was not the Irish version which, of course, has proved itself infallible; it was on BBC. One question was something like: "Who is the fictitious Irishman after whom a law is named which says that if anything can go wrong, it will." A contestant answered "Murphy", and was deemed correct.
Now, I was surprised because I thought Murphy was neither Irish nor fictitious. The accepted wisdom is that the eponym was one Edward A. Murphy jun, a US Air Force engineer. In 1949, high profile and very expensive rocket tests to assess human tolerance to acceleration went wrong because a set of 16 sensors attached to various parts of a subject's body had been designed so they could be mounted wrong way round - and they were. Murphy drew his famous conclusion, it was repeated at a press conference, and has become almost an axiom in the intervening years.
Murphy's original version, reportedly, was: "If there are two or more ways to do something, and one of those ways can result in catastrophe, then someone will do it." But Edward A. Murphy, as far as we know and give or take a likely Irish ancestor or two, was as American as apple pie.
Murphy's Law, of course, does not apply to meteorology. Faulty forecasts may occur, for example, because of uncertainties in assessing the existing state of the atmosphere at any time; the picture is built up from weather observations made at places perhaps 100 miles or more part, and there may well be critical, unknown developments in between.
Moreover, the mathematical equations used in the computer to describe the behaviour of the atmosphere are not exact; they are approximations. And even if the pressure pattern and the positions of the fronts are pin-pointed by the computer with precision, there may be insufficient information from which to estimate the cloud, the gustiness of the wind, or the heaviness or persistence of the rain.
But faulty forecasts, here in Ireland anyway, are never, ever due to Murphy's Law or human error. Neither does Hanlon's Razor hold the key. The assertion of the unknown Mr Hanlon was a refinement of Occam's Razor, which makes the philosophical point that Entia non sunt multiplicanda praeter necessitatem: "No more things should be presumed to exist than are absolutely necessary." Hanlon's Razor prescribes that we should "Never attribute to malice that which can be adequately explained by stupidity." And neither quality has ever played a part in Irish meteorology. Well, hardly ever.