Abacus Clock

The Technical University of Munich is a highly praised school for all forms of engineering. This is very clear when entering the building, which is full of bizarre mathematical art ranging in various levels of absurdity.

The most notable examples are the two giant parabolic slides that go from the fourth floor down into the canteen. But this is not the only mathematical wonder that is worth seeing here, and there are many interesting geometric shapes and drawings all over the building.

One of the more curious pieces is a large abacus, about 3 square feet in size, that seems to move on its own every minute. Many passersby get slightly confused by its design, not immediately noticing that it is actually a clock. And those that do recognize this abacus is a timepiece often don’t understand how to read it, as it uses an interesting counting mechanic. 

The abacus clock (abakus uhr) has four columns of beads divided over two rows. A single bead in the top row and four in the row below. Every minute one bead will move up on the fourth column until all four are in the up position. One minute later the top bead will come down, signifying that five minutes have passed. Repeat the process again and the bead will move back up and one bead on the third column will move to signify 10 minutes. This third row shows the tens and the two rows left of that show the hours. 

So for example, the time 2:07  would look something like this:

0 0 0 *

* * * 0

-------

* 0 * 0

0 0 0 0

0 * 0 *

0 0 0 0

0 0 0 0

It’s little wonder that the time of day isn’t the first thing that comes to mind!