With a heavy heart we share the sad news that Dr. Koos Kortland, a long-term ESERA member and former treasurer of the ESERA executive board, has passed away on February 22, 2023.

Koos Kortland was a special man who contributed a lot to physics education. In September 1980 Koos came to work in the Utrecht physics didactics department, in a project aimed at a thorough modernization of physics education in the Netherlands (PLON project). Koos became editor-in-chief of a new method for senior physics, which built on the PLON project. Parallel to these activities, Koos worked on a PhD research on promoting student decision-making in the context of environmental issues. He wrote articles, became project leader of the mobile radiation project and modernized the physics lab for students. Koos was also editor-in-chief of a book on physics teaching methodology for teacher training.

Koos has served as treasurer on the ESERA Board for a total of 12 years. He was a welcome participant at the major biennial conferences. His favorite event was the ESERA Summer School for PhD students. He was closely involved in this, in various roles and finally as an enthusiastic organizer of last summer’s excellent Summer School in Utrecht 2022.

As ESERA treasurer, Koos was a master in the way he presented the annual financial figures at the General Meeting of Members. He turned this usually the most boring item on the agenda into the most humorous part of the meeting: in the form of a scientific presentation and accompanied by music, Koos guided the attendees through the balance sheets and settlements. Many came to the General Assembly just to hear Koos. Koos will be remembered as a striking teacher: a modest, conscientious hard worker, a pillar of teaching methodology.