Beside the partial eclipse on the 14th of
October 2004, Martin could photographed another atmospheric light phenomena.
The
‚green
flash'
or the
green jet
results from wavelength dependence. Because the
bending
of the sunlight is in the blue range
stronger
than in the red range, the red portion sinks under the sun disk whereby
the green and the blue portion rather can bee seen over the sun
disk.
Our sphere-shaped atmosphere
acts as a lens to lift the sun’s image. The blue and green 'suns' are
lifted more than the red one, but we rarely see the blue rim because blue
light is mostly scattered away to form the sky color above us.
 |
 |
 |
|
green flash |
blue flash
|
blue flash |
The short-wave
(green, blue) part is could be seen after ‚the actual'
sunset. The so-called
“green flash”
or
“green jet”
can be visible for a fraction of seconds and in the rarest case you
recognise a
“blue flash”
With these absolute photo rarities Martin
was successful
to take up even
the
"blue
flash“.
I have to admitt that I never saw a ‚blue flash' photo before.
A picture of
the sun of the
McMath-Pierce Solar Telescope at Kitt Peak,
and a scetch map
clarifies a little this light
physics.
in
deutsch
