Re: [Plib-users] Shadow

[Wolfram K. <w_...@rz...>]

Randall wrote:

>Real empirical science ... I can provide a few (old) references for
>those that are interested.

Yes, please do. I haven't heard of the effect. However, the opposite
is true: Just outside of the shadow, it is a bit darker. Ok, let me do
a Gedanken-experiment as well ;-):

You have a perfect, directed lightsource (parallel light), not a sun.
You have Steves metal plate a bit above the ground.=20

In first approximation, no direct light from the light source hits the
shadow and outside the sahdow the light intensity is 100%, that is,
its as high as it would be without the plate.=20

But if you are accurate, the light can slightly bend around objects
since it is a wave. You can see this effect on water waves and perhaps
remeber Huygens principle from school. This means, the parts of the
shadow close to the rim are light a bit. This light of course has to
come from somewhere, so just outside of the shadow you have less than
100%.=20

But, of course the physiolgical effect Steve spoke about (that
differences are exegarated by your eyes/brain) is much larger.

>Randall

Bye bye,
Wolfram.