I preface the above with ‘I believe’, as I cannot confirm it in any dictionary I possess or can find online. It is, however, known as a ‘Caltrop’ and that is in my dictionary. However, I still prefer ‘Tiswas’ as a contraction of ‘It is as it was’.
All the above has some relevance to the carving as it does not have any designated base and can be placed on any of its four sides. Also it does not have a front or back. I have had a prototype of this that has been sitting on the mantle shelf for thirty years. I look at it every day and still have not got tired of it. The outside shape is deliberately simple and exactly the same from all six sides. The inside shape is similarly standardised, but move the sculpture round by as little as one degree, and the view through the work to the inside changes massively. That I have not taken the idea further in all that time says something about my thought processes, but I don't know what.
The Tiswas Pentagon also has thousands of different view points.