Each week we do a recap for all of those who aren’t following us on Twitter and might have missed out on some of the top stories in photography that we covered. However, Twitter isn’t the only place where we’re posting interesting and beautiful things. Over on our Facebook page hardly a day goes by where we’re not sharing a photo of earth, the sky, or even the cosmos. Some of these pictures look impossible. A few look like something you’d expect to see in a movie like Avatar — but every last one of these photographs shows real phenomena that can be seen on the planet Earth.
This photo was taken by Lisa D. Walker.
Anyone who paid attention in science class knows that rainbows are formed when sunlight enters a raindrop. The beam of light is slowed down and refracted, dispersed, and reflected. When the light is bent in the raindrop, its colors will separate according to the least-to-greatest refraction. Red light refracts the least and violet the most hence the rainbow’s red-orange-yellow-green-blue-indigo-violet color scheme.
However, when a secondary rainbow appears as is seen in this photo, you can spot two things. First, the color order is reversed and the colors are not as sharp as they are in the primary rainbow. The reversal of the colors is because the light is reflected twice within the raindrop — the second reflection inverts the color order. This second reflection not only reverses the colors, it also diminishes the intensity which is why the secondary rainbow is very different looking from the primary rainbow.
Kidding! These are lenticular clouds. Stationary, these lens-shaped clouds are formed at high altitudes with a base that can be stationed anywhere between about 2,000 to 7,000 meters above sea level. Lenticular clouds form when moist air is forced to flow up around mountains and large hills. The water is supercooled and condensed from air with a temperature below the dew point. Aircraft pilots do their best to avoid these clouds as they are places of extreme turbulence. The turbulence (aka “bumpy air” for anyone who’s flown recently) is caused by rotor circulation. This kind of air circulation forms within the lee of the barriers (mountains or hills) or within a valley and is hence known as a type of lee eddy. The surface wind of the cloud, however, is flowing in the opposite direction to the gradient wind creating turbulence for airplanes.
Still, some adventurous glider and sailplane pilots like to see these kinds of clouds because the air currents around them can provide great vertical lift, allowing these smaller, more maneuverable craft, to climb to extreme altitudes for gliding.
Like a tornado, a spout can pick up and carry some rather interesting objects. They have sucked up and spit out showers of tadpoles in New York and toads in France. One spout in Providence, Rhode Island, rained fish down on people. The more intrepid amongst those individuals collected and sold the fish, giving a new twist to the phrase “when life gives you lemons…”
This photo was taken by Fred K. Smith.
It’s spectacular sight and it’s one of many spectacular sights you could see if you head over to Facebook and “Like” our page there.
— da Bird
If any of the images used in this post were captured by you, please post a comment and let us know so that we can give you proper credit.