Re: [Phys-l] Good Questions

[Brian Whatcott <betwys1@sbcglobal.net>]

At 08:30 PM 10/7/2006, John D.,  you wrote:
>  [Cliff Parker ]
> > I am looking for good questions
>
> Here's a simple one:
>
> Suppose you are sitting on the bottom of an ordinary swimming pool, several
> feet below the surface.  You have an ordinary hose that leads to open air at
> the surface.  You breathe in through the hose, and breathe out bubbles (to
> ensure that the hose doesn't fill up with exhaled air).
>
> This scheme is not widely used.  Why not?

This question is of surprizingly immediate concern to blue-water sailers.
Their hulls attract fauna, despite hull coating intended to dissuade
barnacles from staying - and it is their desire to fare their hulls
 by jumping in and scraping off.   They DO use air pipes as an
alternative to sub-aqua gear,but not for the lower hull.

I recall that Humphry Davy of the Royal Institution investigated
means to prevent the corrosion of the copper cladding of the timber
 hulls of the Royal Navy's ships. He came up with cathodic protection,
which the RN enthusuastically adopted - for just a few months:
the copper cladding no longer dissolved, and the marine life no
longer stayed away.


Brian Whatcott    Altus OK    Eureka!