Photo credit: www.technologyreview.com
“It’s a remarkable discovery,” comments Matteo Borrini, a forensic anthropologist affiliated with Liverpool John Moores University in the UK, who did not partake in the study. “It sheds light on how brain preservation can occur… extreme circumstances can lead to extraordinary outcomes.”
Unveiling the Glittering Remains
Buried under layers of ash for centuries, the ancient Roman city of Herculaneum continues to unveil a wealth of historical treasures. Excavations conducted over the past few hundred years have unveiled an extraordinary array of preserved remains, including bodies, structures, furniture, art, and even food, all of which have enriched archaeologists’ understanding of daily life in ancient Rome. Despite numerous discoveries, the site remains a source of ongoing revelations.
Approximately five years ago, Pier Paolo Petrone, a forensic archaeologist from the University of Naples Federico II, was examining the remains of what is believed to be a young man, around 20 years old, initially unearthed in the 1960s. These remains were located within a structure identified as a potential place of worship, suggesting that the individual may have been tasked with its protection. He was found lying face down on a wooden bed.
As Petrone documented the man’s carbonized remains, he observed something unexpected while working under a lamp. “I noticed small, glass-like fragments glimmering in the volcanic ash that filled the cranium,” he recounts in correspondence with MIT Technology Review. “The fragments appeared dark and shiny, somewhat resembling obsidian.” However, he notes that unlike obsidian, the glassy artifacts were surprisingly fragile and easily crumbled.
An analysis of the proteins within the sample indicated that these glassy remnants were likely preserved brain tissue. Detailed examinations using microscopes revealed identifiable neurons present within the material. “I was thrilled because I realized that the preserved brain was an extraordinary find, unparalleled in any archaeological or forensic setting previously recorded,” he expresses.
Guido Giordano, a volcanologist at Roma Tre University in Rome and contributor to the study, noted the importance of understanding the process behind the transformation of the brain into glass. To investigate this phenomenon, he and his team subjected minuscule fragments of the glassy brain material to extreme temperatures in a controlled laboratory environment. Their aim was to determine the “glass transition state”—the temperature threshold where the material shifts from a brittle to a pliable state.
These experimental findings indicate that the material constitutes a type of glass, forming when temperatures plummeted from above 510 °C to ambient conditions, according to Giordano. “The duration of the heating period must have been limited; otherwise, the tissue would have been completely destroyed,” he notes. This may explain why the brains of other individuals found in Herculaneum were not preserved.
The brief phases of extreme heat could have been a consequence of intense volcanic gases combined with layers of ash that settled over the city shortly following the eruption. Subsequently, denser pyroclastic flows from the volcano likely impacted the structures hours later, allowing for a quick cooling of the brain before the destructive forces fully reached it.
Source
www.technologyreview.com