Series "Sky Events" - Mirage of the sun, self-adhesive - Germany / Federal Republic of Germany 2019 - 70 Euro Cent

Every now and then we are lucky enough to witness an extraordinary natural spectacle. Above all, heavenly phenomena, which are often based on the refraction of light, cause great astonishment. For example, if hot and cold layers of air meet, they affect the rays emanating from the sun differently. This is how the phenomenon of mirages arises. Probably every one of us thought before, the road would be wet, even though it is not. What we really see is a reflection of the sky. If the road is heavily heated, the air temperature rises directly above it. The air at eye level of the observer, however, is colder. With a correspondingly large angle of incidence, the light above the road is reflected upwards, so we look at a reverse image of the sky. As a mirage, the so-called lower mirage occurs increasingly in deserts. This effect works just as well the other way round, but upper mirages are rarer. This is above a cold a warm layer of air, which is often the case over water. The light is redirected according to the same principle, but this time down. As a result, reflections in the sky are possible, depending on the atmospheric conditions and curvature on the head or mirrored several times and are accordingly upright. Incidentally, the myth of the Flying Dutchman could be based on this phenomenon. With good luck in the morning or evening, when the sun is just above the horizon and the rays pass through different layers of air, you can observe unforgettable events. Those who have not experienced it themselves can hardly believe that it can be completely distorted, severed or seen several times and mirrored upwards or downwards depending on the layer of air. As shown on one of the stamps of the series "Himmelsereignisse", it can even be square. The motif was created in southwestern France near the city of Bordeaux, overlooking the North Atlantic. Self-adhesive, smaller than the gummed version, available exclusively as a set of 20 together with "Rainbow fragment"