Cerenkov light

[Helmut Wabnig <.... .-- .- -... -. .. --. @ .- --- -. DOT .- ->]

There are not so many Cerenkov light fotos around,
while cleaning up my mess here I found an old picture.
If you are interested look at
http://www.members.aon.at/hwabnig/SeibersdorfReactor1967.jpg
That photograph dates back  1967, quality is not overwhelming.
There were about 10 meters of water downwards and on the surface
they had a small yellow rubber duck swimming because the water
is absolutely clear, surface almost invisible.
Unfortunately the duck had left the nest at the time of the photo.
Seibersdorf is near Vienna, Austria. The reactor is history.
w.