Boerhaave Kaleido-fidget: turn one disc and remake the picture

How can a few mirrored shapes create what seems like an endless set of patterns? Rijksmuseum Boerhaave turns that question into a Kaleido-fidget a child can take home. Participants choose colours and forms, then assemble several rotating layers. A push of the finger makes the pieces overlap, separate and return to symmetry while the eye keeps trying to turn moving fragments into a complete picture. It has the instant satisfaction of a fidget toy and the repeatability of a science experiment: change the angle, order or speed and the result changes with it.

Boerhaave tells five centuries of Dutch science and medicine, from microscopes to astronomical instruments, with a recurring idea: tools change how people see the world. This workshop shrinks that theme into the palm of a hand. It is aimed at children aged six and over, with adult supervision required. One same-day workshop ticket covers up to two adults and four children, so a family can work as a small team. Places are issued only on the day rather than through online advance booking, which rewards an early, flexible start.

• Available daily from 10:30 to 16:30 until 30 August.
• Recommended for age 6+; an adult must accompany children and English speakers can participate.
• The workshop is free with museum admission; one activity ticket covers up to two adults and four children.
• Address: Lange Sint Agnietenstraat 10, 2312 WC Leiden; collect the workshop ticket on the day.

Hokimi field note: ask the service desk about the day’s workshop tickets immediately after arrival, then plan the permanent galleries around the allocated time. The object contains moving components, so adults should help younger makers assemble it and keep small parts secure later.