Scientists are coming up with ways of looking underground without digging anything up, preserving heritage for future generations.

Quote

Physicists are closing in on new techniques to put ancient archaeological sites through a cosmic "CT scan" to look for hidden chambers, using showers of subatomic particles known as muons.

The idea was first put to the test in an Egyptian pyramid four decades ago - but researchers saw no surprises in that experiment. Now, scientists are hoping to enlist a new generation of muon detectors to solve long-running mysteries of the Maya.

Roy Schwitters, a physicist at the University of Texas in Austin, provided an update on his team's plans for archaeological scans on Sunday at the annual New Horizons in Science briefing, presented in Spokane, Wash., by the Council for the Advancement of Science Writing. You can click through an early version of his PDF presentation here.

Schwitters and his colleagues are focusing on mounds in the jungles of Belize that are thought to cover the remains of structures dating back to the Classic Maya era (A.D. 250-900) or even earlier.

"There is good reason to believe they contain rooms and chambers ... that have been likely undisturbed since the time of the Maya," Schwitters told the audience here in Spokane. But you can't dig up the sites willy-nilly looking for lost tombs, and non-invasive techniques such as ground-penetrating radar, electrical probes or seismic sampling "just can't work in this medium," he told me during a Q&A.

This is where muons just might ride to the rescue. When cosmic rays hit Earth's atmosphere, they spark showers of muons and neutrinos that interact only weakly with intervening matter. The neutrinos are almost unaffected as they pass through our planet, but different densities of matter deflect the muons to different degrees. Thus, it's possible to build muon detectors to determine what those subatomic particles have passed through.

"It's just perfect for what we want to do," Schwitters said.

Over the course of several months, one detector can build up a picture showing the "shadows" of surrounding objects - like buildings on the Austin campus, for example. If you put in multiple detectors, or move a single detector to multiple locations, you can create a 3-D picture of the site using muons, in the same way that CT scans produce a 3-D picture of your body using X-rays.

Rest of the article here http://cosmiclog.msnbc.msn.com/archive/200.../22/423358.aspx