Argue all you want, but for all those espousing the benefits of/trying to dispel the inherent safety of not wearing a helmet, either on the road or off road, then fill your boots. You are doing society a favour in saving the rest of us from your stupidity
You have to ask why evidence that helmets don't work as well as people assume provoke reactions like this - ie ones devoid of rational argument and phrased in terms of utter hate. The obvious suspicion is that the person doing the reacting relies on his helmet as a security blanket and isn't interested in facts. So when people say stuff like "The guy who is the UK's main expert witness on helmets says that you're being a bit optimistic" the response is FEAR!!!! WAAAH! HATE YOU!!!
Adults otoh are always interested in facts. And if someone presents a claimed fact that they think isn't true, then they discuss it logically to say which party is mistaken. In fact, this is virtually the definition of being a functioning grown-up.
As you are so keen to quote diatribe, which you have read meticulously, and obviously fully believe, I find it rather strange that you missed the fact that I stated that the polystyrene compressed by a good 10 to 20% in the lower rear left. This is at the point of impact. Don't be fooled into just reading and regurgitating the facts which suit your argument.
Whether you wish to wear a helmet is your own decision - I care not.
However, it is interesting that one professional area that continually states that they see a marked reduction in head injuries within the helmet wearing fraternity is A&E Doctors. I will take their advice rather that some "scientist" who may or may not have been lobbied by the pro or no wear groups.
I am a material scientist, and fully understand the relationship between stress/strain, rate of such stress and strain and the elastic, plastic and brittle failure of materials. This helmet compressed, thus it provided a degree of protection to my sons head.
You are correct that it probably didn't take all the force, and I admit to not having set up accelerometers, or monitors to allow me to prepare a thesis on this. Perhaps you will accept my apologies for not having filmed the accident to provide proof of the fact that his head hit the floor first.
That is what happened, and both he and I will continue to wear helmets whilst on and off road.
2012 CannondaleSupersix Ultegra (54cm)/2014 Saracen Kili Flyer X (M)