Have you ever stopped to think why you find something beautiful? Sure, it's pleasant to look at, but why? Cultural norms play a big role in the way we perceive the world around us, but when it comes right down to it some things are just innately pleasing. For centuries many scientists and artists alike have been researching and implementing Phi, a curious quantity that appears in the proportions of the human body, plants, DNA and the solar system, to name but a few.

Derived from the Fibonacci Sequence, Phi is valued at 1.618 (approximately) and also known as the Golden Ratio or Devine Proportion. In its most basic form Phi results when a line is divided in such a way that the ratio of the length of the entire line to the length of larger line segment is the same as the ratio of the length of the larger line segment to the length of the smaller line segment. Quite a mouth full, hey? Buildings like the Parthenon, the pyramids and the Notre Dame Cathedral all have elements of Phi in their design, which explains why these structures appear naturally graceful despite their massive bulk.

According to Dr. Stephen Marquardt, a former plastic surgeon, beauty can be construed as an archaic survival mechanism that ensures humans recognize and are attracted to one another. This hypothesis implies that the most beautiful faces are simply the ones that are most effortlessly recognizable as human.

Dr Marquardt has constructed a template that, when digitally fitted over a give set of facial features, determines how closely those features resemble the idea of ?perfect beauty?. Comprising of decagons and pentagons, the mask embodies Phi in all of its dimensions and a different template exists for Asian, African and Caucasian features. Some celebrity faces that fit the mask include the likes of Jessica Simpson, George Clooney and Tom Cruise.

When confronted with patients who seek to balance out real/perceived imbalances in their facial features through affordable cosmetic surgery, many plastic surgeons turn to the principle of Phi for help. An excellent example of the occurrence of Phi in the human face can be found in the composition of the human smile. The front two incisor teeth form a golden rectangle, with a phi ratio in the height to the width. The ratio of the width of the first tooth to the second tooth from the center is also phi. Women whose breast-to-hip ration complies with Phi seem to be in balance even if their actual measurements are larger than the norm. Both Marilyn Monroe and Kate Moss? measurements comply to Phi and no-one can dispute the fact that these two beauties are like chalk and cheese. Yet their beauty is legendary. Knowing this, plastic surgeons can endeavour to rectify imbalances with the help of this established set of ?rules?.

The theory is not accepted in its entirety by all professionals, although its relevance is not directly disputed. Some may argue that beauty, as the age-old saying goes, lies in the eye of the beholder. Quirky beauties like Kirsten Dunst and Maggie Gyllenhaal have a unique kind of charm despite the fact that their facial dimensions do not conform to Phi and all its pesky particulars.

I guess it's up to each person to decide for themselves. In a world increasingly obsessed with cosmetic surgery and achieving physical perfection it is frighteningly easy to lose sight of the fact that flawlessness does not necessarily equate to true beauty.