Italian researchers are worried that Michelangelo's statue of David may be in danger of collapsing due to weakened ankles.
Experts have long been concerned that the marble statue, which is roughly 500 years old and has long stood as one of history's most triumphant achievements in art, may have suffered structural damage, the U.K.'s Telegraph explains.
How so? Thousands of people visit the statue every day and over the course of hundreds of years, their footsteps combined with the rumble of nearby traffic have apparently taken a toll on the statue, experts from Italy's National Research Council and Florence University found.
The relatively poor quality of the marble used to sculpt David, the biblical slayer of Goliath and historically righteous king of Israel and Judah, is thought to have played a part in its present troubles. For hundreds of years it was displayed outdoors, sometimes at a slight angle.
Experts do not believe the statue is in any immediate danger of falling over, but a strong earthquake could potentially fell the marble king.
To find how dangerous cracks could be to the statue's longevity, experts constructed replicas of David's ankles and then exposed them to varying degrees of pressure, Discovery reports.
"Micro-fractures are visible in the left ankle and the carved tree stump (that bears some of David’s weight), threatening the stability of the sculpture,” the National Research Council warned in a statement.
The cracks have been known to experts for some time, Discovery noted. In the Journal of Cultural Heritage, Giacomo Corti, a researcher at the council's Institute of Geosciences and Earth Resources, wrote that the cracks "were first detected between 1852 and 1872 and nowadays they are more extensive than in 1872."
In 1991, a man broke the statue's toe with a hammer, claiming a Venetian painter's model from the 16th century had ordered him to.
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