Frans Maes of the Netherland Sundial Society writes: "We deeply regret to inform you that Hans de Rijk, founding member in 1978 and honorary member of the Netherlands' Sundial Society, passed away on November 23, at the age of 95. He served in the Board of the Society for many years and wrote some 150 articles in its Bulletin. Among these were important contributions, such as a latitude independent sundial, and the family of equator projection dials. A more playful result of his creativity were 'postcard dials', which he used to design while waiting for his Chinese take-away dinner."
"Hans was a popularizer of mathematics and astronomy and wrote many books about these subjects, under the pseudonym Bruno Ernst. His motto was: "Nescius omnium curiosus sum", I don't know anything but I am anxious to know everything. His eagerness to learn was equalled by his striving and ability to teach. He has been a teacher of mathematics and physics, founded the mathematics magazine 'Pythagoras' and the physics magazine 'Archimedes', aimed at secondary school students. He founded the first public astronomical observatory in the Netherlands. He also founded the organization 'Ars et mathesis', where art and mathematics meet, and its magazine with the same name. He became friends with the famous Dutch artist Maurits Cornelis Escher and wrote several books about Escher's work. Later on, he wrote extensively about impossible figures."
"Planetoid 11245 bears his name.".
"We lose a generous, inspiring, modest and productive diallist and friend."
The Netherland Sundial Society web pages is available in English at: https://www.dezonnewijzerkring.nl/pages/en/welcome.php?lang=EN