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Emergency braking and bird anatomy [was: Re: DVD copying and CSS]



On Sun, Feb 22, 2004 at 08:07:07AM +0000, stephen parkinson wrote:
> Nano Nano wrote:
> >I'm a grown adult who in various small ways makes a conscious choice to 
> >violate certain laws, in a non-harmful way.  This occurs at many levels 
> >in society (5 miles over the speed limit).  The distinction is: DO YOU 
> >HARM ANYBODY.
> >
> >Dig?
>
> not until the following occurs......
> 
> current driving advert in the uk, suggests that travelling 5mph over the 
> 30mph limit, moves your stopping point about 20ft on, and the kid 
> doesn't bounce very well.

That's a stupid advert. What it actually demonstrates is that the
driver in the advert doesn't know how to brake in an emergency
situation - the car slides to a halt with its front wheels locked. If
the driver had avoided locking the wheels the car would have stopped
in time.

It also demonstrates that you shouldn't run out into the road without
looking, and that parents whose kids lack road sense should keep them
under control near roads.

Mind you, it took me a long time to even realise what the advert was
supposed to be about - because it also demonstrates a significant fact
about bird anatomy. In most animals, the muscle to raise the forelimbs
is connected between the limb and some point on the back. In birds,
the muscle to raise the wings is located in the main mass of breast
muscle; it comprises a quarter of the mass of the breast musculature,
shares in its internal air-duct cooling system, and runs up between
the shoulder joints to pull the wings up by a sort of sheave (pulley
with non-rotating wheel) to convert the downward pull of the muscle
into an upward pull on the wings. The reason for having such a massive
muscle is clearly shown by the beautiful slow-motion shot of a pigeon,
in the foreground, taking off almost vertically, and generating thrust
on the upstroke as well as on the downstroke.

-- 
Pigeon

Be kind to pigeons
Get my GPG key here: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x21C61F7F

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