Physics Photo of the Week

  Physics Photo of the Week October 21, 2022 First Rime Ice - Fall 2022 This Wednesday morning (October 19, 2022) brought the first rime ice deposit on the Great Craggy Mountains overlooking Warren Wilson College in the midst of fall colors.  This is a sign that winter is about to descend. The whiteness on top of Craggy Gardens, which I call "Craggy", is due to the frost on the twigs and remaining leaves on the trees of the mountaintop at high elevations (higher than 5000 ft above sea-level).  What looks like frost from a distance, is frozen cloud droplets, that were below the freezing point while within a descended cloud.  The cloud droplets were super-cooled below the freezing point of water (32 deg F).  As soon as the droplets collided with a leaf or twig, they were stimulated to freeze immediately because the twigs and leaves provided nucleation sites to attract the crystallizing super-cooled water. A much more vivid color photo was made the last time Physics Photo of the

October 7, 2022 Ian's Fury - all photos courtesy of NASA GOES image viewer Last weekend's terrible hurricane was easily seen from spacecraft and made public on NASA's website: GOES image viewer (https://www.star.nesdis.noaa.gov/GOES/index.php ).  This website takes you to a whole array of images from different wavelengths of light.  This image combines nighttime images taken with infrared light that can see the tops of clouds at night as well as the city lights.  Some of the clouds are thin enough that the infrared cameras can see the city lights through the clouds for much of the southeast coastal states.  The hurricane shows its well-formed "eye" at its core as well as the tops of numerous thunderstorms formed off the coast over the Atlantic.  Click on the image for an animation and an explanation of the animation properties. Why does a hurricane rotate counter-clockwise?  This is a phenomenon called the Coriolis effect.  The Coriolis effect is a rotational f