Ecologic urgency : Air traffic excess

Dean wrote: Equality 7-2521 wrote: Dean wrote: The T wrote: Mr ProgFreak wrote: The T wrote: I wonder if birds also ruin our skies... For all we know, without birds in the sky the sun might be purple. Damn! Suspend all bird traffic now! Except ostriches, emus, rheas, penguins and kiwis How can we say that those birds wouldn't fly if the sky wasn't so filled with airplanes? We had best ban their flight to be safe. Stop me if I'm wrong, but I think penguins need pretty high humidity to fly.

They might need less dense bones too.

Equality 7-2521 wrote: Just to be a little technical Dean the sun is slightly yellowish (slightly very key). This and the composition of our atmosphere (and probably our eyes a little bit too but I know much less about the human side) account for a deep blue rather than a violet from the scattering. The white hazy appearance of the sky directly above us is, in addition to what you have been saying, dependent on another type of scattering which is less predominate called Mie Scattering.

Coming back to the optical science of vision for a moment - the colour response of the human eye changes with light intensity (I touched on this earlier - in very low light levels we discard colour information from the cone receptors completely and rely on the rod receptors alone). Under normal light levels we peak in the yellow/green region (M & L cones in the following graph) so are more sensitive to yellows and greens.