Unlocking Secrets: How a Young Man’s Brain Turned to Glass During the Mount Vesuvius Eruption, According to Scientists | CNN

Glass doesn’t usually form from organic materials, but something interesting happened in 2020. Researchers found a shiny black glass inside the skull of a person who died during the famous eruption of Italy’s Mount Vesuvius in AD 79.

Now, scientists believe they have pieced together what happened to this individual, a young man discovered in the coastal town of Herculaneum, buried face down on a bed under layers of volcanic ash. They think the extreme heat created from the eruption transformed his brain tissue into this unique glass.

The analysis of the glass shows that the young man’s body must have reached temperatures above 510 degrees Celsius (950 degrees Fahrenheit) before cooling quickly. This rapid temperature change is what allowed the glass to form in a process called vitrification.

Guido Giordano, a volcanologist at Roma Tre University, explains that the quick cooling is key to turning anything liquid into glass. He compared it to how volcanic glass, like obsidian, forms when lava cools rapidly, such as when it meets water.

Curiously, researchers noted that pyroclastic flows, which are fast-moving clouds of hot volcanic material, could not have caused the glassy transformation of the young man’s brain. The temperatures in these flows didn’t rise above 465 degrees Celsius (869 degrees Fahrenheit), and they cooled slowly.

Instead, they suspect an intensely hot ash cloud that spread quickly during the eruption created the conditions necessary for this rare phenomenon. However, the specific circumstances that led to this vitrification are still under debate among scientists.

The skull and spine may have shielded the brain from being completely broken down by the heat. While pyroclastic flows are heavy and stay close to the ground, ash clouds can rise high into the air, spreading hot particles that can be deadly.

Giordano and his team experimented with the glass samples taken from the skull and spine to discover the temperatures needed for vitrification. They found that brain tissue could turn into glass only when exposed to very high heat followed by rapid cooling.

The ash cloud likely caused an immediate fatality for those below it, engulfing them in scorching temperatures around 510 to 600 degrees Celsius. At the bottom of the ash layers in Herculaneum, they found fine ash, likely from the same ash cloud.

Some experts, like forensic anthropologist Alexandra Morton-Hayward from the University of Oxford, doubt that this glass is actually brain tissue. She argues that organic materials typically need to be frozen at extremely low temperatures to avoid damage—a process known as cryopreservation.

Giordano, however, insists that the glass is indeed of organic origin. Studies have indicated that neurons and proteins from the young man’s brain were preserved, adding more intrigue to this extraordinary historical find.