Getting the facts straight

On Saturday night my wife and I went down to Te Awamutu to watch ‘Sherlock Holmes’   – there being no cinema in Cambridge 🙁   It was a moderately naff piece of film – more James Bond than Sherlock Holmes – though quite suitable for some mindless Saturday night entertainment so long as you were prepared to put Sir Arthur’s original creation to the back of your mind for a couple of hours.

Anyway, it inspired me to read again some of the stories, so I picked up the ‘Complete Sherlock Holmes’ from the shelf and, not wishing to drudge through A Study in Scarlet or The Sign of Four, I started with the first of the short stories, A Scandal in Bohemia.  N.B. I have read every one of the stories and novels – and could recount the plot lines for many of them – but A Scandal in Bohemia is one that escaped my memory.

There’s a place in it that Holmes makes a fantastic comment on his methods. It’s pretty well known – google it and lots comes up. Watson asks if Holmes has any theory about the case, and Holmes explains that he can’t possibly have a theory, because he doesn’t yet have any data.

 It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories instead of theories to suit facts.

 It’s a great explanation of doing science. Let’s start with what we know (the data) before coming up with an explanation. It’s all too easy to have an explanation (something we’d like to be true – perhaps because it will bring in a nice big piece of industry funding if it is) and then go fishing for the data that supports it (and if we catch something else just through it back in the lake and wait until something more suitable turns up).  Not the way to go.

Kind of related to this, I too have been reading some of the ‘alternative therapies’ that have been reviewed recently by the NZ Herald. There’s plenty of other blog comment on them, for example Alison’s one here.  I loved Saturday’s on Ganbanyoku – Japanese hot rocks. I’m sure lying on a hot rock can be very relaxing (so long as it’s not too hot), but let’s stick to what we know, rather than reporting total rubbish, shall we?

Unlike the sauna, stone bed [sic] heats through your body evenly and gently and not through the skin

says the hot rock expert. Let’s think about that one. Doesn’t heat you through the skin? Now, the last time I looked, most of my body was covered in skin. Are we meant to believe that somehow the heat gets in exclusively through our eyes, mouth and other unmentionable parts? Maybe a clue to the thinking comes later on in the article, with the journalist writing

As you lie on the stone bed, it gently heats you from the inside, gently spreading the heat around your body…

 Aha! So it’s the old microwave ‘heating from the inside out’ myth, is it? The mysterious heat of the rocks somehow gets to your inside without first having travelled through your outside? Now, there’s three ways heat moves – conduction, convection and radiation. Given the subject is lying blissfully in direct contact with the rocks, and there’s not a great deal of air inside the human body, we can rule out convection. While the hot rocks will happily emit infra-red radiation, the chance of it getting inside you without being absorbed by the skin and other tissue on your periphery is pretty low. How do I know this? If it were otherwise, one could ‘see’ inside you using an infra-red camera. And I know from my use of them, as fun as imaging the human body is, you don’t get to see inside, X-ray or MRI style. (At least, not directly. One can look for hot or cold patches, that may be related to tumors beneath the surface, but it isn’t SEEING inside you.)  So, that leaves conduction. And, unfortunately conduction of heat from A to B involves going through all places in between. That means your skin.

So I think there has been a bit of twisting the facts to suit the old heat-from-the-inside myth. And I’m sure there are plenty more where that one came from.



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