In Western jewelry, the infinity-symbol-shaped knot has symbolized endless love and constancy as far back as 500AD, when it was employed in Celtic rings. The sentimental Victorians loved the knot as an emblem for undying affection: it loops around itself in an eternal twist, forever and ever, never beginning and never ending. In a time when lovers were often parted for long periods, it could be a comforting metaphor for intimacy despite being apart. Think about what would happen if you pulled both ends: the further the distance, the tighter the knot.