A leather shoe has been dated as the oldest in the world using analytical chemistry
techniques and accelerator mass spectrometry, defying the scientists who found it and their predictions that it would be between six and seven centuries old.
In fact, the footwear found in an Armenian cave is 5,500 years old - a statistic verified through analytical chemistry
in three different ways.
Two of those ways applied mass spectrometry to date the leather of the shoe, which was pre-treated with an acid-base-acid sequence, rinsed then bleached before radiocarbon measurements were carried out.
For the third dating, grass found inside the shoe was subjected to a similar process, providing independent support for the contemporaneity of the sample.
Dr Ron Pinhasi, lead author of the research from University College Cork in Ireland, says: "We thought initially that the shoe and other objects were about 600-700 years old because they were in such good condition."
It is thought that a layer of sheep dung in the cave where they were found helped to preserve the shoe and the other items discovered nearby.