When lights whirl over the clear winter night sky north of the Arctic Circle, everyone raves about the fascinating spectacle. The polar lights are nature’s mystical show and appear when electrically-charged particles are transported over the earth’s atmosphere via a solar wind, thus activating a celestial extravaganza of light.
The typical colour of this celestial phenomenon – also called the Northern Lights – is a bright green – which, like the “Saléve Vert” on the BMW Concept M8 Gran Coupé, can change to a greyish blue. Polar lights also appear in red, violet, white and yellow.
What many people don’t know: The Northern Lights can also be admired at the earth’s South Pole: the so-called Southern Lights.
What looks like a scene from the movie “Avatar” is in reality one of nature’s wonders. Microscopic algae fluorescently light up the water at night. Biologists call this light phenomenon bioluminescence. It can be observed, for example, on the beach of Mosquito Bay on the Caribbean island of Puerto Rico.
Algae can produce glow through biochemical processes in special organs. But other living beings also have this ability. Fireflies, for example, communicate this way.
In 2017, researchers actually succeeded in using enzymes to transform plants into natural light sources, which could replace conventional lamps in the future.
Polar stratospheric clouds
The world-famous painting “The Scream” by the Norwegian painter Edvard Munch is said to be inspired by the breath-taking glimmering of the polar stratospheric clouds. The phenomenon – called “mother-of-pearl clouds” – arises from tiny ice crystals in the stratosphere, which are illuminated by the setting sun in the dark night sky. The rare colourful clouds form at temperatures of -78 degrees Celsius and can therefore only be admired near polar regions such as Alaska, Siberia and Norway.
Ice Crystal Halos
What looks to us like a supernatural halo in the sky is the fascinating light phenomenon of the ice crystal halos. Halos are formed by the reflection and refraction of light on tiny floating ice crystals in the air. The mysterious light-circles form in various shapes around the sun and moon and can be admired all over the world at any time of the year.
Everyone has seen a colourful rainbow before. Much less common is a fog arch or white rainbow, whose light band is twice as wide. The fog arch is created when a fog wall of fine water droplets is illuminated by sunlight and the light is reflected when entering and leaving.
The fog arch can only be observed when the observer stands in front of the fog wall with his back to the sun. It can be found in a wide variety of places, but it is particularly frequent in peat bogs, mountainous regions or near the sea.
What is flip-flop paint finish?
A flip-flop paint finish is a special-effect varnish that changes its colour depending on the viewing angle and is usually used for car paint. To achieve the optical effect, the normal varnish is mixed with effect pigments. The pigments responsible for the colour change are called interference pigments. Depending on the viewing angle, these interference pigments amplify some wavelengths, while other wavelengths are eliminated by superimposing them.
In the BMW Concept M8 Gran Coupé, the luxurious flip-flop paint finish “Saléve Vert” gives the vehicle an unusual appearance. The colour changes from green to greyish blue depending on the changing light, emphasising the expressive surfaces and contours of the vehicle, as well as underscoring its sporty and elegant look.
By the way: there are also flip-flop paint finishes where not only the colour changes, but also the brightness. In addition to the automotive industry, flip-flop finishes are also used in the printing and cosmetics industry.