Nuxx:4e2ee563$0$2540$da0feed9@news.zen.co.uk

Path: num2.nntp.dca.giganews.com!num1.nntp.dca.giganews.com!number.nntp.dca.giganews.com!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!goblin2!goblin.stu.neva.ru!news.stack.nl!dedekind.zen.co.uk!zen.net.uk!hamilton.zen.co.uk!shaftesbury.zen.co.uk.POSTED!not-for-mail Message-ID: <4e2ee563$0$2540$da0feed9@news.zen.co.uk> From: Nuxx Bar  Newsgroups: uk.rec.cycling Subject: Re: Saved by her helmet Date: Tue, 26 Jul 2011 17:03:45 +0100 References:       <595fa591-a35d-4e56-81b2-0d1978629521@b19g2000yqj.googlegroups.com> <1FjXp.110517$fl.45522@newsfe23.ams2> Lines: 26 User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.7; en-US; rv:1.9.2.18) Gecko/20110616 Thunderbird/3.1.11 MIME-Version: 1.0 In-Reply-To: <1FjXp.110517$fl.45522@newsfe23.ams2> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Organization: Zen Internet NNTP-Posting-Host: d25c6ad3.news.zen.co.uk X-Trace: DXC=;\9=DUH;jk916I<3@m2[j=nok4Z\ On 25/07/2011 20:37, Simon Mason wrote: >> On Jul 25, 8:21 pm, "Just zis Guy, you know?" >>  wrote: >>> -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 >>> >>> On 25/07/2011 12:26, Greentable wrote: >>> >>>> Please can you explain how the helmet hit a hard surface, it >>>> was cracked in three places, and yet it absorbed no energy >>>> whatsoever. >>> >>> It's made of polystyrene foam, which absorbs little or no energy >>> in brittle fracture. A helmet that has broken has failed, they are >>> designed to absorb energy by crushing. > >> That's right. Since it did not crumple and thus absorb the energy of >> impact, it failed in its primary design. > > Well, we don't know without seeing it - there may be some evidence of > crushing - but it would be unusual if it did show any such evidence, the > pictures of failed helmets on the intertubes generally don't. > > I suspect the former medical students involved are unaware of these things.

Why do you wear a helmet then, Guy?