Sep 10

What’s Up in the Sky

What’s Up in the Sky – September, 2020

Astronomy as an Art Form

There’s way more to astronomy than just “what’s up in the sky”. Sometimes the intersection of several branches of science or the combination of science and art can lead to some fascinating discoveries or the confirmation of existing theories.

Such is the case with the Dutch artist Johannes Vermeer’s 1696 masterpiece, View of Delft, the painting that has been hailed as Vermeer’s greatest work. Vincent van Gogh described it as “incredible”. French writer Marcel Proust thought it was “the most beautiful painting in the world”.

However, there has never been total agreement about the actual date the work was created. The appearance of the trees and boats and the various lighting effects created on the canvas led to all sorts of conclusions regarding the date and time of day depicted.

A recent article by Donald W. Olson and others in the September issue of Sky and Telescope magazine describes how astronomers answered the question of when the piece was actually painted. According to the authors, “The dark town wall and entrance gates make a dramatic contrast with brilliant sunlight that illuminates Delft’s tiled roofs and the tower of the Nieuwe Kerk (New Church).” This octagonal tower was crucial in determining the time of the painting.

First, the exact direction of the main face of the tower (which is still standing) was determined using Google Earth. Simple geometry then determines the orientation of all eight faces of the octagonal tower. The apparent size of the tower in the painting is another critical factor so the authors actually travelled to Delft and used their tape measures to find out for themselves.

Knowing the exact orientation and dimensions of the tower, the team was able to narrow down the date of the painting to two possibilities, one in April and one in September. The dates were based on the pattern of sunlight on the many facets and architectural features of the tower. Knowing the dimension and orientation of each detail, they were able to determine the exact location of the Sun in the sky. Factoring in the time of day from the image of a clock face in the painting enabled them to determine the two possible dates. Because the painting depicts trees in full foliage, the April date was rejected and it was determined that the piece was done at 8 a.m. on a date near September 3.

The exact year took a little more detective work. In 1660, a clock and bells were installed in the octagonal tower, but these are not shown in Vermeer’s painting. Therefore, the date of the work is thought to be September 3, 1659.

I found this to be a fascinating example of how our endeavors here on Earth are intrinsically linked to what’s up in the sky.

This month in history:
Sept 1 Pioneer 11 is first spacecraft to fly past Saturn – 1979
Sept 3 Last two Apollo Moon landings canceled by NASA – 1970
Sept 8 Voyager 1 launched – 1977
Sept 10 Surveyor 5 lands on Moon – 1967
Sept 23 Premier of “The Jetsons” – 1962
Sept 25 59 – day Skylab 3 mission ends – 1973