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Limits of the New Science: An Interview with Dr. Hawass

Photo of Dr. Hawass Despite the wealth of information we now have about ancient Egypt, we really know very little of what we could know. "We have found only 30 percent of what is there," says Dr. Zahi Hawass, the chief archaeologist for the pyramids, who oversees all archaeological excavations in Egypt. Seventy percent of ancient Egypt, then -- pyramids, tombs, mummies, art, and artifacts -- still lies hidden beneath the desert sands.

Recently, some archaeologists have begun teaming up with geoscientists to use the sophisticated technology from their field to help uncover Egypt's buried treasures. Archaeologists are now poring over data from remote-sensing satellites, for example, to look for the tell-tale signatures of limestone blocks, pottery shards, and stone fragments. The satellites beam pulses of microwaves toward the Earth. How the microwaves bounce back toward the satellite depends on the density of objects on the ground, which allows researchers to distinguish man-made objects -- the scattered blocks of a ruined pyramid, for example -- from natural structures. With optical images from satellites and aircraft, researchers can map the shapes of the objects.

On the ground, other techniques are used. Researchers send pulses of radar into the ground, chart tiny changes in the magnetic field of the soil, and check for variations in electrical resistance. The idea is that unusual readings may point to the presence of archaeological gold. For example, ground-penetrating radar waves will move freely through the soil until they hit a buried object, like a stone wall. The wall reflects the waves back up toward the surface. Measuring the signals that come back, then, gives a picture of what lies below.

Not all archaeologists are completely sold on the new methods, however. Dr. Hawass argues that when it comes to new discoveries -- finding new tombs, unearthing the rubble of a long-buried pyramid -- technology can still fall short. "I do believe in science, and I believe that science is very important to Egyptology. We can do x-rays of the mummies, and we can do analysis of the pottery to find out dating. We can analyze the mud soils, and do mapping with geographical information systems (GIS) and the Global Positioning System, and with aerial photography." But, he says, there are limits to what the sophisticated methods can do, and those limits need to be appreciated. "People say the radar will show you everything. But when the radar shows you an anomaly under the sand, the interpretation of the anomaly could be anything in the mind of anyone. These scientific techniques need to be developed more, to get more accurate information."

"Therefore, the technique that we've been using until now, and that we'll continue to use, is to dig in the sand with the workmen," Dr. Hawass says. "We've always found our discoveries in that way -- sometimes with the information about where to dig coming through word of mouth, and often through research. My research helped to discover the tombs of the workmen who built the pyramids (as described in the SECRETS OF THE PHARAOHS episode "Lost City of the Pharaohs"), and the Tomb of Osiris at Giza. Accidents are also always happen in everything -- we found the Valley of the Golden Mummies in the Bahariya Oasis by accident."

And when it comes to excavation, Hawass says, there's no substitute for old-fashioned elbow grease. "There is no technique that can compare to digging with workmen in the sand. It is the most accurate and safest method of excavation, because we know what we are doing."

For more information: Geophysics and Archaeology.

Secrets of the Pharaohs