Additional optical principles in Moonrise over Willoughby Lake:
- Diffuse reflection
from the middle of lake. There is a small breeze in the middle of
the lake. Look carefully and see another reflection of the moon,
but this one is much more diffuse. The wind creates small waves,
which make much more varied angles of the water surface. Each
tiny ripple reflects light in a different direction causing the diffuse
reflection - like the reflection on a frosted mirror.
- Earth's shadow.
Look at the brightness of the sky above the base of Willoughby
Notch. Notice that the sky is much darker the closer the sky is
to the horizon. This is caused by the earth's shadow in the
atmosphere soon after
sunset. The upper part of the air in the sky is still illuminated
by the direct sun's rays. This photograph was taken exactly 3
lunar cycles before the expected total lunar eclipse of Oct. 27,
2004.
- Additional phenomena.
There are several other physical phenomena illustrated in
the photograph. If you see any other effects, please feel free to
discuss them with the author: Donald Collins at Warren Wilson College
Physics Department. E-mails are welcome, but the e-mail address
is not
published on this page.
