Second scientific mural in Utrecht: Ornstein on the Oosterkade
Since last Tuesday, tram passengers passing through station Vaartsche Rijn will be able to enjoy a mural honouring Prof. Leonard Ornstein. The mural depicts the Ornstein-Uhlenbeck process: a random movement that bears a resemblance to the path of a drunken walker. The mural was initiated by physicists Sander Kempkes and Ingmar Swart, in collaboration with Utrecht artist collective De Strakke Hand. The final touches were added to this second formula mural on Tuesday, 5 May.
How many Utrechters are aware of the ground-breaking discoveries that have been made in their city, by people who walked the very same streets? In order to raise awareness for Utrecht’s scientific discoveries, several murals of scientific formulas are appearing on walls around the city.
Following the first painting, which was dedicated to Prof. Buys Ballot, the new mural honours Prof. Leonard Ornstein (1880-1941). Together with Prof. George Uhlenbeck, Ornstein described the Ornstein-Uhlenbeck process, a ‘random walk’ in which an object makes a series of random movements. The mural can be found on the facade of Oosterkade 30.
A specific example of these random movements is when a drunk tries to walk home from the bar. Several random steps can follow as the person tries to walk forwards, stumbles backwards or steps to the left and right to maintain his balance. A single random movement is usually not very interesting, as it is completely random, but when one examines the statistical average of 100 drunken walks, it can be entertaining to ask whether the average drunk will ever reach their home, or if they can even leave the bar.
Random movements are extremely common in the real world. One example in nature is how an albatross searches for food. It begins by circling above a point in the water for some time, but when no food can be found there, the albatross will fly to a random new location. Other examples are fat globules moving through milk, the elasticity of rubber and even the movements of stock exchange prices are described using these kinds of random movements today.
Physics laboratory in Utrecht
In addition to his scientific work, Ornstein made many contributions to the field of physics in the Netherlands. He supervised a record number of 94 PhD candidates, engaged in many partnerships with industrial enterprises, and served as one of the founders of the Netherlands Physical Society, which is still very active today. Ornstein was also the Director of the Physics Laboratory from 1920 to 1940. The laboratory was located in the Bijlhouwerstraat, near the new mural.
Five artists from De Strakke Hand completed the mural in only 12 days: Stefan van den Heuvel, Ort Willems, Roosmarijn ten Hoopen, Astrid Oud and Michiel Meulemans.