Powerful 3D Imaging Tools Reveal Ancient Secrets

A process known as computed tomography scanning, or CT for short, has revolutionized scientists' ability to investigate the past. Using devices a trillion times more powerful than hospital X-rays machines, scientists can peer inside priceless fossils without destroying them.

Paleontologists and anthropologists face a fundamental challenge in their search for remains of the distant past. The substances and environments best suited to preserve fossils, such as rock or the tree resin amber, are often impossible to open up and look inside. The very toughness and durability that made such materials perfect for preserving fossils often make it impossible for scientists to access the desired remains without also destroying them. And if the rock is solid or the amber is dark, then whatever is inside must remaining tantalizingly out of reach.

CT scanning gets around this thorny problem by showering the artifacts with highly focused X-rays in quantities that would kill a human. The most cutting edge version of the technology uses synchrotron scanners that can produce beams a trillion times the brightness of normal X-ray machines. The resultant images are incredibly high resolution, and when mapped together can be used to create full 3D models of the encased specimen.

Another advantage of CT scanning over standard X-ray technology is its ability to detect different densities. The X-ray machines found in hospitals can differentiate between only four densities, CT scanners can discern over a hundred separate densities. This not only makes the task of peering through solid rock surprisingly easy, but also it helps scientists learn even more details about the fossil itself. Such precision has allowed researchers to study such highly focused topics as the inner ear canals of a 35 million-year-old primate, which in turn makes it possible for anthropologists to deduce how the animal would have moved.

Although CT scanning is hugely promising, it does have its limitations. It is still only possible to analyze fairly small samples, and there are only about fifty machines in the world that can perform the task. The hardware requirements are also enormous - a 100 million-year-old wasp was imaged using the European Synchrotron Radiation Facility, a particle accelerator almost a fifth of a mile wide. Even so, the images thus far have been so promising that there remains much cause for optimism, as a whole world of previously invisible specimens wait to be digitally uncovered.

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