The golden ratio
The golden ratio is roughly equal to 1.618. The special nature of this ratio appealed to the Greeks, who thought that objects in this proportion were particularly aesthetically pleasing. It has been said that they used this ratio in their architecture and statues to ensure their beauty, for example the dimensions of the Parthenon. In fact, throughout history there have been a number of pieces of art that exhibit the golden ratio: Leonardo Da Vinci’s paintings or Michelangelo’s David. However, it has been debated whether Ancient or Renaissance artists consciously used this ratio, or whether it is simply a numerological coincidence.
It's believed that the Golden Ratio has been in use for at least 4,000 years in human art and design, but it may be even longer than that – some people argue that the Ancient Egyptians used the principle to build the pyramids.
In more contemporary times, the Golden Ratio can be observed in music, art, and design all around you.