Sacred geometry · Measured
Is the golden ratio in art and architecture?
Sometimes, on purpose: Salvador Dalí painted The Sacrament of the Last Supper (1955) on a canvas of 267 × 166.7 cm, a ratio of 1.6017, and Le Corbusier built his Modulor measuring system on it between 1943 and 1950. The most famous claims, the Parthenon, the Great Pyramid and the Mona Lisa, either do not measure up or have no record behind them. Pick a building or a painting below and measure it against φ = 1.618 yourself.
The test
A fair way to check a golden ratio claim
Divide the long side by the short side and see how close you get to 1.618. That is all a golden ratio claim says. A golden rectangle is one whose sides are in the ratio 1 to φ, where φ = (1 + √5) ÷ 2 = 1.6180339887...
How close is close enough? The mathematician George Markowsky set a rule in 1992: “I will consider a claim for the presence of Φ to be at least reasonable if the computed ratio is within about 2% of Φ.” That gives his acceptance range, “the range 1.58 to 1.66.” It is the copper band on the number line above.
Why a band and not one exact number? No building or canvas is measured to the millimetre, and you can choose where to put your ruler. Markowsky called hunting for φ among many possible measurements “the Pyramidology Fallacy”: measure enough lengths of anything and some pair will land near 1.618. A claim is strong when the ratio is close, the measurement is the obvious one, and the maker left a record saying they meant it.
History
Euclid, Pacioli and Leonardo
The ratio was first written down as geometry, not as a rule for beauty. Euclid’s Elements defines it as cutting a line “in extreme and mean ratio”:
“A straight line is said to have been cut in extreme and mean ratio when, as the whole line is to the greater segment, so is the greater to the less.”Euclid, Elements, Book VI, Definition 3 · translated by T. L. Heath
Euclid used it to build the pentagon faces of the dodecahedron. He never called it golden or divine.
The art link starts with a friar and a painter. Around 1496 the mathematician Luca Pacioli went to Milan, where he worked on a book about the ratio. MacTutor: “Pacioli began work on ... Divina proportione and the figures for the text were drawn by Leonardo.” It was printed in Venice in 1509.
That meeting came late in Leonardo’s career. Markowsky points out that Leonardo’s “acquaintance with the divine proportion dates from his meeting with Luca Pacioli, which occurred 13 years after he painted St. Jerome.” So a golden rectangle drawn over the earlier St. Jerome cannot be something Leonardo learned from Pacioli.
“Golden” came last of all. The German name goldener Schnitt, golden section, first appears in print in 1835, in a textbook by Martin Ohm. The letter φ was suggested in the early 1900s by Mark Barr.
Measured · Egypt
The Great Pyramid: φ fits, and so does π
The pyramid passes the test, but it passes a second one too. Markowsky used a base of 755.79 feet and a height of 481.4 feet. Cut the pyramid down the middle and the sloping face, the slant height, is 612.0 feet, while half the base is 377.9 feet. In his words: “612.01/377.90 ≈ 1.62 which differs from Φ by only 0.1%.”
Now try π with the same numbers. Four times the base divided by the height is 4 × 755.79 ÷ 481.4 = 6.28, and 2π = 6.283. Markowsky: it is “well within ±2% of 2π.” Both fits come from one slope, so the measurements alone cannot tell you which, if either, the builders meant.
No record ties φ to Egypt. The popular story that Herodotus described the golden ratio in the pyramid traces back to John Taylor’s 1859 pyramid book, and Markowsky found that Herodotus’s text “does not support the story.” His conclusion: “It does not appear that the Egyptians even knew of the existence of Φ much less incorporated it in their buildings.” Press Great Pyramid above to see the slant swung down onto the base.
Measured · Athens
The Parthenon: 2.25, not 1.618
The Parthenon’s front is much wider than a golden rectangle. With a width of 101 feet 3.75 inches and a height of 45 feet 1 inch, Markowsky found: “width/height ≈ 2.25 = 9/4 and length/width ≈ 2.25 which are well outside the acceptance range.”
Measuring to the roof peak does not rescue it. Up to the top of the triangular pediment, 59 feet: “101/59 ≈ 1.71 which also falls outside the acceptance range.” A golden rectangle as wide as the front would have to be 62.6 feet tall, higher than the peak.
Look closely at the famous diagrams. Most draw a golden rectangle over a photo of the front. Markowsky: “None of these authors is bothered by the fact that parts of the Parthenon are outside the golden rectangle.” Press Parthenon above: the dashed golden rectangle and the building do not line up.
No record · Florence
The Mona Lisa: no documentation
There is nothing to measure against, because no one knows where the rectangle is supposed to go. Mario Livio, writing for the University of Cambridge’s Plus Magazine, put it plainly: “No documentation exists to indicate that Leonardo consciously used the Golden Ratio in the Mona Lisa’s composition, nor to where precisely the rectangle should be drawn.”
That is the problem with most overlays on paintings. A face, a canvas edge or a hand gives dozens of possible starting points, and a golden rectangle or golden spiral can be slid around until it touches something. Leonardo drew the figures for Pacioli’s book, which shows he knew the ratio later in life. It does not show he painted with it.
On purpose · 1955
Dalí’s Last Supper: a golden canvas
Here the golden ratio is the size of the canvas itself. The Sacrament of the Last Supper, painted by Salvador Dalí in 1955, hangs in the National Gallery of Art in Washington. Its catalogue size is 166.7 × 267 cm, and 267 ÷ 166.7 = 1.6017, about 1% below φ and well inside the pass band.
He put a second golden object in it. Livio: “Dali also incorporated in the painting a huge dodecahedron (a twelve-faced Platonic solid in which each side is a pentagon) engulfing the supper table.” In a regular pentagon, each diagonal is φ times the side. Livio calls Dalí a painter “about whom there is very little doubt that he actually did deliberately include the Golden Ratio.”
On purpose · Architecture
Le Corbusier’s Modulor
The clearest case in architecture is a measuring system made for the purpose. The Fondation Le Corbusier says the architect “developed the Modulor between 1943 and 1950, with the help of his workshop (mainly Gerald Hanning).”
It is a scale of sizes built from the human body. “After being designed for a stature of 1.75 m (Le Corbusier’s own height), it was finally based on a man’s height of 1.83 m or 6 feet, inspired by the Fibonacci sequence and the golden section.” He published it in two books, Le Modulor (1950) and Modulor 2 (1955). Unlike the Parthenon, nobody has to guess here: the architect wrote it down.
Tested on people
Do people prefer golden rectangles?
Mostly not, when it is tested. Markowsky quotes a review by Schiffman and Bobko: “Research on the golden section proportion as an empirically demonstrable preference has most often been applied to the rectangle where the results, on the whole, are negative.”
In his own informal tests, the favourite was 1.83. When people picked the rectangle they liked best, “the most commonly selected rectangle is one with a ratio of 1.83”, outside the pass band. His verdict: “The various claims made about the esthetic importance of the golden ratio seem to be without foundation.” Press Favourite above to see how much longer 1.83 is than φ.
You can still use it as a guide. Nothing stops you using φ as a composition guide, the way photographers use the rule of thirds; it is a choice, not a law the eye obeys. To try it on your own pictures, load one into the Golden Ratio Lens; the photo stays on your device.
What is proven
Fact and tradition, sorted
| Claim | Status |
|---|---|
| Dalí’s Sacrament of the Last Supper is a golden rectangle. | Real · 267 ÷ 166.7 = 1.6017, on purpose |
| Le Corbusier’s Modulor uses the golden section. | Real · his own system, 1943 to 1950 |
| Leonardo drew the figures for Pacioli’s Divina proportione. | Real · printed 1509 |
| The Great Pyramid was built on φ. | Fits · 1.62, but 2π fits too; no record |
| The Parthenon’s front is a golden rectangle. | No · 2.25, or 1.71 to the peak |
| Leonardo used φ in the Mona Lisa. | No record · nothing documents it |
| The nautilus shell is a golden spiral. | No · measured about 1.33 |
| People prefer golden rectangles. | Mostly no · favourite in tests 1.83 |
Questions
The golden ratio in art and buildings
Is the Mona Lisa based on the golden ratio?
There is no evidence it is. Mario Livio: “No documentation exists to indicate that Leonardo consciously used the Golden Ratio” in it, nor where the rectangle should be drawn. Leonardo met Luca Pacioli, the writer of the 1509 book on the ratio, late in his career.
Is the Parthenon a golden rectangle?
No. Its front measures about 101 feet wide by 45 feet high, a ratio of 2.25. Even measured to the top of the roof peak, 59 feet, it is 1.71. Both are outside the 1.58 to 1.66 range that counts as close to φ.
Do the pyramids use the golden ratio?
The Great Pyramid’s slant height divided by half its base is about 1.62, within 0.1% of φ. But the same measurements also give 2π, and there is no record that the Egyptians knew of φ. The numbers fit; the intent is unproven.
What famous paintings use the golden ratio?
The clearest case is Salvador Dalí’s The Sacrament of the Last Supper (1955): its canvas is 267 × 166.7 cm, a ratio of 1.6017, and it shows a huge dodecahedron. Mario Livio says there is very little doubt Dalí used it deliberately.
How do you use the golden ratio in your art?
Use it as a placement guide: put key lines about 0.618 of the way across the frame, or follow a golden spiral toward your subject. It is a composition rule like the rule of thirds, not a law of beauty, and tests have not found that people prefer it.
Which architects used the golden ratio?
Le Corbusier did, on the record. He developed the Modulor between 1943 and 1950, a scale of sizes based on a 1.83 m man and inspired by the Fibonacci sequence and the golden section, and published it in 1950 and 1955.
Sources
Where this comes from
- George Markowsky, “Misconceptions about the Golden Ratio,” The College Mathematics Journal 23(1), 1992, pp. 2 to 19: umcs.maine.edu.
- Mario Livio, “The golden ratio and aesthetics,” Plus Magazine, University of Cambridge, 2002: plus.maths.org.
- National Gallery of Art, Washington, open data, object 46590, The Sacrament of the Last Supper: github.com/NationalGalleryOfArt.
- Fundació Gala-Salvador Dalí, Catalogue raisonné of paintings, P 719: salvador-dali.org.
- Fondation Le Corbusier, “Corbusean vocabulary”: fondationlecorbusier.fr.
- Euclid, Elements Book VI, Definition 3, translated by T. L. Heath, Perseus Digital Library: tufts.edu.
- J. J. O’Connor and E. F. Robertson, “Luca Pacioli,” MacTutor: st-andrews.ac.uk.
- Jeff Miller, “Earliest Known Uses of Some of the Words of Mathematics (G),” MacTutor: st-andrews.ac.uk.
- Ivars Peterson, “Sea Shell Spirals,” Science News, 2005, reporting Clement Falbo’s nautilus measurements: sciencenews.org.
- Eric W. Weisstein, “Golden Ratio,” MathWorld: mathworld.wolfram.com.
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