Straight lines

Straight lines

Tracy&James | Sunday, 4 October 2020

There is a saying amongst the scientific community where I work – “if you want a straight line then just make two measurements”. It is often said largely in jest, but sometimes it is used as a damning indictment of a lack of data or an extrapolation gone too far in a paper or other publication. It is also strongly linked with another trait that I’ve previously written about here, confirmation bias. It’s human nature not to seek out data that shoots down your own argument, but in science it’s vital that you leave your ego behind and search for the data that contradicts your hypothesis, because if you don’t do it, someone else most certainly will.

It doesn’t matter how complicated a mathematics function is, if you zoom in close enough it can appear as a straight line.  Hopefully everyone can see that any forecasts based on such a ‘straight line’ are completely erroneous.  

Many years back someone must have been musing over fly casting by pulling the line back from the tip of the rod and watching as it fired forward.  I suspect they did this over and over again until they came up with the thought that the rod is acting as a big spring – we must bend it and the unloading of that induced elastic potential will propel the line forward.  In fact with most casts you see the rod bend first and then straighten as the line overtakes the tip, so it’s obvious isn’t it? I guess this concept was discussed amongst the fly casting community and no one objected massively.  The rest is history, and for the next thirty years (I guess, perhaps ‘big-spring’ is much older?) we are told at various demonstrations etc. that a deep rod loading is the key to a good fly cast.  However, I suspect we all now know that ‘big spring’ works for the bow and arrow cast but not a lot else.  It’s an extrapolation too far based on flawed observations.

The ‘wave’ hypothesis for fly line propagation is exactly the same.  Sure, there are obvious waves in certain fly casts, however a blinkered ‘all fly-casting must therefore be a wave’ approach will eventually go the same way as ‘big spring’.  I have no issue with using the concept of waves to help instruct – I’m sure done in the right way it could produce excellent results, but then so can ‘big spring’.  But please don’t present it as ‘physics’ because ultimately it’s a zoomed in view of things where the bigger picture simply does not fit.

Today I have been decorating.  I completed a room in our southern house, Tracy and I agreed it looks ok, certainly better than it was.  However, to a professional decorator I suspect it looks like a dog’s dinner, a real bodge, poorly executed and amateurish.  That’s the thing with professionals, they see things others don’t.

Have a great week, James.