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What is the golden ratio and what are its rules?

Published in Golden Ratio 3 mins read

The golden ratio, often called the golden number or divine proportion, is a mathematical concept representing a specific ratio between two numbers, approximately 1.618. It's deeply connected to the Fibonacci sequence.

Understanding the Golden Ratio

Definition

The golden ratio is a relationship where the ratio of the sum of two quantities to the larger quantity is the same as the ratio of the larger quantity to the smaller quantity. Mathematically, if 'a' is larger than 'b', then (a+b)/a = a/b, which equals roughly 1.618.

Symbol

The golden ratio is often represented by the Greek letter phi (φ).

Golden Ratio Formula

The formula can be expressed as:

φ = (1 + √5) / 2 ≈ 1.6180339887

Golden Ratio and Fibonacci Sequence

The golden ratio is closely linked with the Fibonacci sequence.

Fibonacci Sequence

This sequence begins with 0 and 1, and each subsequent number is the sum of the two preceding numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, and so on.

Connection

As the Fibonacci sequence progresses, the ratio of each number to the number before it gets progressively closer to the golden ratio (approximately 1.618). For instance:

  • 3/2 = 1.5
  • 5/3 = 1.666...
  • 8/5 = 1.6
  • 13/8 = 1.625
  • 21/13 = 1.615...

These ratios approach the value of 1.618 as numbers increase.

Rules and Properties

While there isn't a set of "rules" in the traditional sense, the golden ratio has significant mathematical properties and principles:

  • Mathematical Property: The defining property is that the ratio between the two segments is 1.618, which can be expressed with the equation above.
  • Ubiquity: It appears naturally in several contexts including the arrangement of leaves, spirals in pine cones and sunflowers, and the structure of shells.
  • Aesthetics: It's often used in art, design, and architecture to create visually pleasing compositions.
  • Self-Similarity: Golden rectangles (rectangles with sides in a golden ratio) can be divided into a square and another smaller golden rectangle, and this process can be repeated infinitely.

Practical Examples

  • Architecture: Many ancient and modern buildings use the golden ratio in their proportions for aesthetic purposes.
  • Art: Artists often incorporate the golden ratio in their composition to achieve balance and harmony.
  • Photography: Photographers utilize the golden ratio in composition techniques to place subjects in visually appealing positions, for instance, using the rule of thirds, which is an approximation of the golden ratio.

How the golden ratio is used in design

Here is a table that summarizes the applications of the golden ratio:

Area Use Case
Art Composition, proportions, and placement of elements in paintings and sculptures.
Architecture Design of buildings, monuments, and layouts of spaces.
Design Layouts, typography, and user interface designs in digital products.
Nature Analyzing patterns in plant growth, animal body proportions, and natural phenomena.
Finance Technical analysis of stock charts and financial ratios.

Conclusion

The golden ratio is not just a number; it's a concept that appears throughout nature and human creations. Its close connection with the Fibonacci sequence and its role in aesthetics and design make it a topic of interest for mathematicians, artists, and scientists alike. It is often used as a guide for proportions and design choices to provide pleasing results.

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