Beauty fads come and go, and eyebrow shaping is no exception. But what if there were a mathematical rule we could cite as hands-down the perfect shape? That’s the idea behind the patent recently awarded to inventor Anastasia Soare of Beverly Hills, California, for a “brow mapping technique” that hews closely to the so-called “golden ratio.”

The golden ratio is sometimes called the “divine proportion,” or in mathematical terminology, simply *phi*. Its value is usually given as 1.618, although in reality, it’s an irrational number with infinite decimal places, like *pi*. *Phi* describes an intriguing geometrical anomaly. If a line is divided into two unequal lengths, such that the ratio of the longer segment to the shorter segment is the same as the ratio of the whole line to the longer segment, then the resulting number will be something close to 1.618.

*Phi* was first mentioned in Euclid’s *Elements* around 300 BC. Geometric shapes are said to be in “divine proportion” if the ratios of their various sides closely resemble *phi*. The most common are the golden rectangle, the golden triangle, and the pretty spiral observed in a chambered nautilus shell.

Hardcore fans of *phi* often see the golden ratio in art, music, poetry, architecture, even the stock market. In fact, the east and west facades of the Parthenon are said to form golden rectangles (that is, they exhibit length-to-width ratios of *phi),* although some buzzkill mathematicians counter that the ratio is not exactly 1:1.618, but 1:1.71.

Whatever. The point is, *phi* is associated with aesthetic perfection. So why not follow that proportion when it comes to shaping one’s eyebrows? As Soare argues in her patent application:

Many great artists have proportioned their works according to the Golden Ratio, as it is believed to be aesthetically pleasing. Hence, a ‘perfect’ face would display Golden Ratio proportions such as these: Distance from Top-of-the-head to Chin divided by Width-of-head equals .phi.; Length-of-Lips divided by Width-of-Nose equals .phi.; Outside distance between Eyes divided by Length-of-Lips equals .phi.; etc. It follows that, on a ‘perfect’ face, the high point (HP) of the eyebrow would divide the eyebrow arch at precisely the Golden Ratio point between the starting point of the eyebrow (SP) and the ending point of the eyebrow (EP) (SP-HP divided by HP-EP=.phi.).

Thanks to Soare’s ingenuity, soon we’ll all be walking around with perfectly shaped “*phi*-brows.”

[via Improbable Research]

*Images: (top) US Patent #9,204,602. (bottom) The golden ratio in a spiral. Credit: User:Dicklyon/Wikimedia. Public domain.*