= 27d567bc2d48d9f40e9ccc20ea370b15)
jswan comments on Wear a Helmet While Driving a Car - Less Wrong Discussion
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (116)
There are so many variables here. I think most people underestimate the violence involved in a high speed motor vehicle crash. Years ago, I was involved in EMS and responded to a lot of crashes. If we eliminate a) crashes without seatbelts worn (1), and b) crashes without frontal airbags (cars without frontal airbags are relatively uncommon these days, I'd say that most survivable TBIs were caused by either a) side impacts, with the head hitting the window glass, or b) the airbag itself (2). Of those two, the low-to-intermediate-speed side impact is the only one where a helmet would make much difference. Some cars now come with side-curtain airbags, which would help a lot with this.
No doubt, many other crashes result in TBIs, but the forces are so extreme that a small helmet isn't going to help. It's really stunning to see what happens in high-speed impacts.
(1) Without seatbelts, even intermediate-speed impacts result in so much chaotic movement that people tend to fly around inside (or outside) the car and airbags don't help that much. You don't want to be in an ejected-from-vehicle event.
(2) Airbags can definitely cause TBIs by themselves, especially if you're seated very close to them. It's basically a small explosion going off in your face. It's better than hitting the steering wheel or windshield, though.
That seems reasonable.
For saving a life, but it still might help with preserving more of the brain for cryonics.
I wonder if a helmet would reduce the damage caused by an airbag.
I doubt it.
Ordinary helmets are thick. That isn't to make them stronger. Bicycle helmets are made of something like expanded polystyrene: you can push a fingernail into them. I've never worn a motorbike helmet, but they have thick padding inside.
The reason is to make space between your head and the impacting object, so that the impact forces are spread over a longer time as the helmet material deforms. Acceleration = force/time, so increasing the time reduces the acceleration.
A hard shell spreads the force of the blow over a larger area, but does nothing to reduce the acceleration.
An airbag already hits with a large area, so I don't think the Crasche would have any effect in that situation. It's a hard shell with thin padding, so I expect it is of some value against sharp objects and abrasions, but won't alleviate impact forces much. I wonder what their patent claims are.
To answer my own question, here are some of the patents. The claims consist of the design and method of making the protective inserts, not the sort or amount of protection it gives.