white sunlight
red: long waves
...every colour in between
blue: short waves
Sunlight
is
every
colour
mixed
an air molecule
red mostly goes straight on
blue bounces off
in every direction
Rayleigh scattering
Air
scatters
blue
far
more
than
red
you
blue light reaches your eyes from every part of the sky
Blue
reaches
you
from
all
over
the
sky
noon: a short trip through air
sunset: a long trip through air
only reds and oranges make it through
air
At
sunset,
light
crosses
much
more
air
Why
is
the
sky
blue?