The moon does not reflect light

Is Edward Munch mindless when he forgets the moon's reflection in many of his paintings? No, he followed the optical rules.

Edward Munch (1863-1944), the pioneer painter of the school of expression in painting, right from the start of the business in the late nineteenth century, has left many pictures printed with sadness and nostalgia such as: sick children, Screams, Night . These are quite famous paintings and get certain attention.

However, in the twentieth century, he reached his 'golden age' . During this period, his paintings were more vivid and powerful, typically the Young Girl on the embankment . He painted this scene in the summer of 1901 in Asgardstrand, a beach on the West Bank of Oslo Bay. In 1933, the director of the Oslo National Center for Fine Arts Exhibition considered the Young Lady on the bank to be the "biggest and most famous painting in Munch's paintings".

The painting poses difficult questions for astronomers . The celestial body drawn to the left of the painting is the Moon or the Sun? At the beginning of growing or diving? Or is it the Midnight Sun? And why don't people see the reflected light of this celestial body on the water? Donald Olson and his colleagues at the University of Texas found the answer.

The picture " Young woman on the dike " was painted by Edward Munch in 1901
(Photo: Allposters.com)

The midnight sunrise was eliminated from the beginning, because Asgardstrand was located south of the Arctic. In this area, at the time of summer solstice, the Sun does not appear. As for the question of whether the Moon or Sun, some say it is the Moon, but some claim it to be the Sun. So there is only way to go where the painter once painted the picture.

Astronomers easily found the place where Munch set the price, and they gave a lot of parameters. They proved that Munch drew a celestial body he saw in a 63-degree azimuth. The visible objects in this sky, seen from Asgardstrand, have a deviation (the angle between an object and the equator of the Sun) about -18 to -20 degrees. As a result, celestial bodies cannot be the Sun (because the Sun is always north of the Sun equator in the summer, meaning there is a positive deviation). The celestial body is drawn so it must be the Moon.

Now we need to explain why the Moon does not shine light on the surface of Oslo Bay? Some people have come up with an explanation that the Moon that the painter paints is symbolic. The fact completely not the case. When he drew this picture, Munch sat 3.4 meters from the water and his vision fell below the white wall surrounding the girls' heads. The house under the moon is 100 meters away from the artist and 15 meters above sea level.

The illustration shows that the straight line connecting the artist and the roof forms a 6.6 degree angle to the horizon. The image of such a roof is seen below the sea level of 15 meters, ie 18.4 meters (15 + 3,4) ' under ' the painter's horizon (ie, at an angle of 10.4 degrees) . By calculation one can determine that the Moon is viewed at an angle of 8 degrees above the horizon, ie above the house. The Moon's reflection will also have to be seen at the same angle, but this view has been reflected by the lost house. Thus, the moon shadow cannot appear. This phenomenon also explains why the roof and its reflections are not the same.

Although Munch's life goes through a lot of tragedies, as we have just seen, he has not lost his ability to think.

Annotation: The laws of reflection explain why there is no moon shadow on the water. The painter sat 3.4 meters above sea level. Because the Moon is located at a distance (almost) infinitely, the reflection angle in the water is equal to the horizon (red) of the observer. However, the reflected image of the house, viewed from a different angle from the corner of the real house, made the artist not see the Moon shine in the water.

According to Ngo Vu - Tia Sang (Translated from Pour la Science, No. 351, January 2007)