One of the “spiral” curves, traced: a circle.
Straight, bent or tilted?
Fraser spiral
Follow the spiral into the middle with your finger. Where does it go?
Nowhere: it isn’t a spiral. Each curve is a circle that comes back to where it started.
Why? Each circle is drawn with little twisted pieces, like a twisted cord. Your brain adds all the small twists together into one big spiral.
Picture: Mysid, Public domain · Wikipedia(opens in a new tab)