A tricky start to the New Year

An unstable stable beginning…

The other day I was looking for an unfinished project of mine, and I came across one of my experiments in it. I had forgotten about it, but I don’t know why, since I still find it intriguing. Take a look for yourself. Let your eyes move up and down the image.


Catenary Illusion

©2020 Chris Culy

catenary illusion

For me, there is a perception of depth, with the lines giving the impression of either a tunnel (convex, with the curve on top) or a basket (concave, with the curve on the bottom). What is intriguing is that the perspective shifts between the two interpretations, often as I am scanning the image up and down — it might start out concave at the top and shift to convex at the bottom, or vice versa. It’s also more likely to happen for me on the left side than on the right.

This is an example of a multistable illusion (a term I just learned), though unlike the other examples on that Wikipedia page, this one isn’t very stable for me. While I’ve enjoyed optical illusions since I was kid, it was fun to create my own, even if only accidentally, as with the Cyclartcy examples.

In any case, a shape shifting image seems an appropriate start for 2021 as we cope with the various changes in the world.


Technical note

The curves are all the same catenary, a shape which I became especially intrigued by after seeing an exhibit in Casa Milà designed (and lived in) by Antonio Gaudì in Barcelona.

Posted in FMOA