Thursday, 25 June 2015

Note on Global Cooling

http://www.theguardian.com/environment/2015/jun/23/weak-sun-could-offset-some-global-warming-europe-us-study

and a note from a commentator on models...discussed this week..online.

Calvin Beisner completely mischaracterises the legendary Feynman's principle (which you can watch here) http://www.presentationzen.com/presentationzen/2014/04/richard-feynman-on-the-scientific-method-in-1-minute.html

 Let me explain where Calvin goes wrong 

 let's say I have a formula, maybe the formula I use for determining weapon damage for my game
in the real world

 then I actually put in some weapon data according to what I observe from martial arts forums and the like

 and I realise that, say, my composite longbow is doing far too little damage compared to what I observe in actual tests: so what went wrong?

 the composite longbow data is incorrect

 well, I've checked it, and it seems okay. That means it's a problem with the formula itself

 2. there's a problem with the model--well, no, because analogous weapons like the crossbow and the shortbow are working fine

 so that leaves 3. the specific interaction between the longbow and the formula is creating a specific problem

 I realise then that the problem was that the formula was not taking into account the fact that the longbow has additional penetrative power vs armour owing to its unusually large power stroke

 now, my formula doesn't take into account the power strokes of various weapons, because it's much simpler than that

 but I can solve the formula by changing how the formula computes the longbow data. 

In the end, I simply change one integer from positive to negative and tell my players "now you have to roll UNDER this value, not above it" and everything works

 the difficulties with climate change are analogous

 A) there is no comprehensive model of weather data. It's far too complex.

 B) the predictive models of the early 90s were, by and large, wrong, because they overestimated the direct influence of carbon dioxide on ambient temperatures

C) IF YOU CORRECT the predictive models of the early late 80s/ 90s by changing ONE INTEGER (ie the precise degree of warming owed to a doubling of carbon dioxide) the formula still works