The star clock, also known as the "nocturnal", is a timepiece invented during the Renaissance.
Using the North Star and the Big Dipper to tell the time
With the help of the star clock, the local time (= solar time) can be read at night from the position of the Big Dipper constellation in relation to the North Star. The instrument consists of two rotating discs, one above the other, with a pointer and a hole in the middle. The date is set on the lower disc. Then, the North Star is sighted through the hole, while the pointer is set to the pole star of the Big Dipper. This allows the time to be read on the upper disc. If it is too dark, the time can even be found by feeling with your fingertips.
For teachers and students
The star clock is easy to build and is ideal as teaching material in secondary schools. Like all other astronomy materials, it can of course also be used for other group and project work on the subject of astronomy and physics.
