Re: Avian Magneto-vision

Michael Ash schrieb:
> Remus Shepherd <remus@[EMAIL PROTECTED]
> wrote:
>>   So birds see magnetic north.  Possibly only at dusk, when the
cryptochromes
>> in their eyes are activated by the deep blue of the sky.

> I imagine such people would make great navigators. Would it be possible
to 
> construct some sort of filter which would allow the ability to be useful

> at all times of the day, and what sort of technology level would be
needed 
> for it?

Creating tinted glass and fixing it to the persons head in a way it 
blocks all unwanted light - nothing to fancy.
To get the magentic sense alone, without the benefit of more traditional 
perception, a blindfold made from translucent blue fabric would do the 
trick.
In both cases you want to figure in a few minutes of accomodation time.

Robert