UK mathematician debunkers myth aboot the Parthenon’s optical illusions

A mathematician has uncovert what micht be ane o the langest-rinnin myths in history efter studyin optical illusions an the Parthenon, the weel-kent Greek temple that luiks doun on Athens.

Scholars hae marvelled at the biggin on the Acropolis hill for mair nor 2,000 year an heaped praise on its airchitects for thair clever uiss o geometry. Its subtle curves are said tae correct optical illusions that wad hae itherwise ruined the Parthenon’s clean lines.

But efter a detailed investigation, an a flurry o mathematical modellin, Prof Alain Goriely at the University o Oxford has reached an awkward conclusion. The optical illusions the curves are meant tae fix are either nonsense or practically imperceptible. In short, the illusions are theirsels an illusion.

In his study, Goriely traces the myth back tae the 1st-century Roman airchitect an engineer Vitruvius who wrate aboot the Parthenon 400 year efter its construction. His accoont fand its way intae airchitectural buiks an became established fact. The day’s AI chatbots still churn oot the tale. “I dae think it micht be the auldest myth that we hae,” Goriely said, “apart frae religion.”

A common claim that the mathematician challenges concerns the Parthenon’s base or stylobate. Measurements shaw the sides o the base are no horizontal but form a gentle arc that rises 6cm in the centre. Accordin tae Vitruvius, this corrects an illusion that wad mak the base appear tae sag in the middle.

The saggin effect has been attributit tae twa proposit tricks o the licht. The first states that lang horizontal lines simply seem tae slump in the middle, but Goriely fand nae evidence for this.

The second suggests that the Parthenon’s marble columns create the illusion. This is based on the Hering illusion where parallel lines on a 2D sheet can luik bowed when ither lines intersect them. But the Hering illusion is strangest when the intersectin lines are at acute angles. The columns at the Parthenon are ower vertical tae produce the illusion, an there is nae pruif it even warks in 3D, Goriely said.

Anither claim is that the bulges in the Parthenon’s columns – a curvature cried entasis – corrects an optical illusion that wad mak them luik ower nairrow in the middle. Again, Goriely fand nae evidence for the illusion. Mairower, the columns at the Parthenon bulge by a mere 18mm, which is barely perceptible at typical viewin distances.

Goriely, who assesses an dismisses ither supposed “optical corrections” in his paper concedes he “fell intae a bit o a rabbit hole” pullin aw the evidence thegither. He suspects the Parthenon’s airchitects had ither reasons for the airchitectural features.

The curve o the base micht hae preventit rain puddles formin an curved columns micht simply hae felt mair organic an visually pleasin tae the ancient Greeks, he writes in Royal Society Open Science.

It is unclear why the myth has endured for sae lang, but Goriely suspects that the perception o ancient Greece as a supremely knowledgeable an ingenious civilisation is partly tae blame.

Unusually for an academic study, Goriely ends his paper by invitin readers tae put it doun an tak a walk in a city. “Trust yer ain een, question what ye see an decide for yersel whether the theory o optical corrections hauds up,” he writes.

Frank Salmon, professor o the history o classical airchitecture at the University o Cambridge, said: “Some experts hae lang been cautious o Vitruvius’s explanations, recognisin the risks inherent in usin his text as a sort o bible tae explain airchitectural practices in Greece centuries afore his time, but also the loss o the mony Greek texts aboot thair temple airchitecture he claimed tae hae read when preparin his ain.”