At the Field Museum, scientists’ research—say, on Paleozoic arthropods or ancient Hopewell spearheads—usually gets folded into slowly, painstakingly planned Herculean exhibits, such as the eon-spanning “Evolving Planet” or the multi-continent-covering “Ancient Americas.” But for the first time, the museum decided to quickly turn around a small sliver of its research and display it to an eager public.
It began as an intensive July CT-scanning session of ancient remains, many not on display since their acquisition during the 1893 World’s Fair. Helmed by anthropology conservator J.P. Brown, the data acquisition turned up revealing information on the museum’s treasured mummies. Approached by exhibition staffers in late October, Brown says his first thought about hastily pulling together a Goliath undertaking, was “Oh, crap.” Dragging out the 1923 museum’s original wood cases and wall-mounting CT scans, the Field Museum opened “Mummies” in February. Here’s what led up to the finished exhibition.
Yes, we scan!
In November 2010, Brown trotted down to the Radiological Society of North America annual meeting—a vast McCormick Place convention with around 700 health-care exhibitors—to see if he could wrangle CT equipment to use at the Field Museum. “I was basically going around begging,” says Brown, who went from booth to booth propositioning radiology equipment companies. One conference participant mentioned that Brown might be able to find a local company with a mobile CT scanner, an entire radiology office stuffed inside a semitruck trailer; such a contraption was a revelation to Brown. He cold-called Genesis Medical Imaging, a Northern Illinois CT equipment company, which happily offered its advanced multislice computed tomography scanner for free. “I wondered if I got that right,” Brown says. “I had to call back to make sure.” Indeed, Genesis offered the scanner for a week. In a flurry of planning, Brown deduced electricity would cost too much—about $20,000 by running a connector from a temporarily shuttered museum elevator. Genesis offered a much easier solution: a diesel generator. Finally, in July, the mobile CT scanner was delivered to the museum’s West Parking Lot. “If my wife would’ve let me, I would’ve slept in it,” Brown says.
Starting in the 1930s, the Field Museum x-rayed its mummies. By using the rudimentary technology, scientists had known that one of its Peruvian mummy bundles, containing a mummified woman, included something else. “We thought it was a part that was broken off,” Brown says. After adjusting the CT scanner and taking careful images, scientists discovered a swaddled newborn.
Scans caught a perfectly preserved ear of corn, assumed to be food for a Peruvian mummy’s afterlife. The food appeared so crisply in the CT scan, “we’re able to count the kernels,” Brown says. Brown’s team could send the image to an archaeobotanist—an archeologist who studies plants—to determine the type of corn.
One of the most surprising and beautiful images: a mummy’s shock of curls, still preserved after more than 2,000 years. To learn more about mummies’ facial features, the museum took photographic slices of two skulls and used them to make plastic 3-D models. An artist is working on “putting flesh on the replica to know what the mummy would’ve looked like,” Brown says.
It’s a boy!
Brown and his colleagues wondered whether one small ancient Egyptian mummy was a female. To determine sex, scientists look at certain bones, including the pelvis, which takes on an appearance specific to its sex around age 20. The CT equipment produced a clear image of the mummy’s pelvis. But results were still inconclusive. Then Brown remembered the CT scanner could also capture soft tissue. Sure enough, a scan of the mummy’s genitals revealed a penis. “I e-mailed everyone the penis image, saying ‘It’s a 14-year-old boy’s penis!’ ” exclaims Brown, who says, in his excitement, he failed to realize his faux pas.
“Mummies” runs through April 22 at the Field Museum.