A mathematical sculpture
These are the Borromean rings:
In between these rings a (minimal) surface may be spanned that is not orientable. Hence it actually has only one side and its double cover is connected.
Here I have made this double cover from clay. The idea is the same as with this sculpture available from Shapeways, but mine is hand work. If I ever get to make a second such thing, I shall document the process and publish a making-of.
The tree no longer has leaves, but in its life it has borne many fruits. Although, they aren't too many actually. Pauca sed matura!
This wireframe model of a Klein Bottle should not be used to store fluids.
Container for all kinds of things
This structure currently serves to store my little collection of nice stones. I used to keep a few salt-stalactites in it which I had grown on a radiator and for which the long recesses in the bottom are intended. Sadly, the stalactites have been destroyed.