Where the circles converge to a point (like at a star), imagine that this is a point of tangency of two spheres, one in front of the picture and the other behind it. (unlv.edu)
Similar to the stock diversification example in Article 7.1, there is a «tangency portfolio» of about 20 % stocks and 80 % bonds that historically has moderately boosted portfolio returns while adding little additional volatility. (mindfullyinvesting.com)
Contemporary sensibilities will relish the diaristic nature of Albers's works - on - paper and, in the case of the lush tangencies of Variant / Adobe, Study for Four Central Warm Colors Surrounded by 2 Blues (ca. 1948), swoon to them. (mnaves.wordpress.com)