When bones get hot, they shrivel. This gives archaeologists and forensic scientists major headaches, because this can make identifying the age, sex, and size of the deceased next to impossible. However, as reported by the BBC, researchers from Portugal are using neutron beams to explore this issue, with hopes of resolving it for good.
“The problem… is that when a skeleton is subjected to high temperatures, like in a plane crash or a bushfire, the bones are altered by the fire. One of those alterations is a change in dimensions,” explained David Gonçalves, a bone specialist from the University of Coimbra, to the BBC.
“We’re trying to see if those changes are quantifiable and if eventually, we can predict the amount of shrinkage – or sometimes there’s even an increase in size. It’s pretty random and we’re failing to understand that process.”
Bring in the neutron beams
That is where neutron beams come in: They allow researchers to probe the crystal structure of bone, burned or not. When neutrons hit a bone sample, they scatter, and scientists then measure how the neutrons have scattered to understand the arrangement of atoms within the bone.
“The reason neutrons are so helpful is that they allow us to see things that [lasers and other light beams] do not allow us to,” explained co-researcher Dr. Maria Marques.
“We are measuring the changes in vibrations within the atoms in the bone. So we are measuring structure.”
By comparing the scatter patterns of burned and unburned samples, they hope to develop a better understanding of how fire alters bones—which could then allow them to examine a burned bone and estimate how much it has deformed since the fire.
“Basically, it’s to return burned bone to its original dimensions, and then it will be possible to apply metric references, as we conventionally do in unburned remains,” said Gonçalves.
So far, Gonçalves and Marques have worked with samples from three previously unburned human skeletons. After examining the bones with the neutron beams, they were burned at 500, 700, or 900 degrees Celsius and tested again—and the results are exciting.
“We are at present quite confident,” said Marques. “[The spectra] look very promising.”
“Although we are still in a very early stage,” cautioned Gonçalves. “The sample is still small. To develop any kind of method that is reliable and has statistically significant support, we need a larger sample.
“We still have a lot of work to do in the next few years.”
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Feature Image: Science and Technology Facilities Counsel
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