THE FUTURE OF THE PAST 1 The Sphinx--Virtual and Real S ITTING AT A computer terminal in Santa Monica, California, I watched the Great Sphinx of Giza take shape before my eyes as a scholar''s careful measurements were transformed into an elaborate wire-frame model, then grew a "skin" that showed not the half ruined statue that now lies in the sands of Egypt but the Sphinx as it may have looked at the time of its creation forty-five hundred years ago, with its nose, royal beard, and headdress intact. Just a few miles away at the Getty Conservation Institute in Marina Del Rey, technicians have compiled data from a fully automated, solar-powered monitoring station placed behind the Sphinx, measuring wind direction and velocity and relative humidity in order to study erosion patterns of the ancient world''s greatest surviving colossal statue. In the basement of the institute, men in white lab coats were testing perfect airless environments for the preservation of the body of King Tutankhamen and his fellow mummies at the Egyptian Museum in Cairo, and the institute has sponsored the virtual reality reconstruction of the tomb of Queen Nefertari so that anyone with a ten-thousand-dollar Silicon Graphics computer can "walk through" her final resting place sixty-five hundred miles away in the Theban necropolis in Luxor. Although these technological marvels are helping to transform the way we study and preserve the historical past, the reality on the ground in Egypt looks rather different. When I first saw the Great Sphinx in 1996, it was covered in scaffolding as Egyptian conservators worked to protect its lion body by encasing its bottom half in newly cut limestone blocks--the latest in a series of attempts to save the Sphinx. Several years earlier, a two-ton chunk had fallen off the chest of the Sphinx, and the soft middle portion of its body continues to flake and chip in pieces that turn to a dust as soft as talcum powder when you rub them between your fingers. Slowly and relentlessly, its body is being eaten at by wind and moisture, aided by the smog of Cairo, which now rivals Mexico City''s as the worst in the world. Behind the rump of the Sphinx, the Getty''s solar-powered monitoring device stood disconnected, tangled up in its own wiring, looking like a space-age music stand alone on a stage without an orchestra.

The Sphinx still stares impenetrably across the millennia but instead of contemplating the mysteries of existence its gaze is now trained at the Pizza Hut and Colonel Sanders Kentucky Fried Chicken restaurants that have opened just two hundred yards in front of it. The urban sprawl of Cairo--which has grown from two to seventeen million people in the last forty years--has reached the feet of the Sphinx and the Pyramids, bringing with it cars, sewage, air pollution, and fast-food culture. "You have arrived in Cairo at a very bad time," an Egyptian voice explained to me in an ominous tone over the phone the day of my arrival at the Nile Hilton. "There has been a theft at the Egyptian Museum. They have just fired the head of the Supreme Council of Antiquities. I''m not sure very many people will be willing to speak with you." A thief had hidden inside a sarcophagus, snuck out after closing time, stolen several gold objects from the collection of King Tutankhamen, and hidden them in the bathroom. He was arrested trying to smuggle something out the next morning.

The incident was seized upon by the minister of culture as an excuse to sack the director of antiquities, who was considered an open, likable person who had worked well with foreign archeologists in Egypt. His successor asserted his power by revoking manyrecent decisions and thundering against foreigners using their work in Egypt to "give their students Ph.D.''s." But how else, the archeologists wondered, are we supposed to train a new generation of Egyptologists? As I was to discover in the next few weeks, the deterioration and conservation of antiquities is an extremely delicate subject in Egypt, and nowhere more so than at the Sphinx--national symbol of Egypt, tourist attraction, and world icon, in which almost everyone feels they have a stake and a say. I headed out to Giza with Mark Lehner, a scholar who teaches at the University of Chicago and who may know more about the Sphinx than anyone else alive. We started in the confusion and traffic of downtown Cairo, crossed the Nile onto its west bank, and drove about seven miles south and a couple of miles inland from the river. "This all used to be farmland when I first came here in 1972," Lehner said as we drove along the Pyramids Road.

Now the road is lined with cheaply built cement high-rises that are already badly dilapidated and black with soot. Although they are less than twenty years old, they are in considerably worse shape than the Pyramids, which begin to appear, majestic as ever, over the roofs crowded by satellite dishes. Not only has the population nearly doubled in the twenty-five years Lehner has been coming to Egypt, it has become infinitely more cosmopolitan. "When I first came, I recall people collecting outside storefront windows where you had a few imported things, silk ties maybe from Italy or a little can of Nescafé," Lehner said. "Now we have McDonald''s, Pizza Hut, satellite dishes, CNN, and David Letterman." As Egyptian society has opened up on some fronts, it has turned inward on others. Just in the last several years, there has been a sudden proliferation of the chador--the veil traditionally worn by Islamic women--which had been gradually disappearing from the streets of Cairo in recent decades. During the 1980s, Lehner was the field director of something called the Sphinx Mapping Project, the first full-scale attempt to scientifically survey and record the colossus with photogrammetric cameras that record and measure the volume of objects with mathematical precision.

The data and images from the Sphinx Mapping Project became the basis for the computer reconstruction of the Sphinx that I had seen in Santa Monica. For five full years, Lehner worked full-time studying, tracing, photographing every inch of the Sphinx. "I spent weeks on top of the back of the Sphinx just doing hand mapping of the outlines," he said. "I spent weeks on top of the paws, mapping all the stones in that area. I knew the Sphinx so well at that time I could go home at night and run all of this detail in my head like a video and think about it." When we met, Lehner was forty-six, a relatively short, slightly built man with round, thin tortoiseshell glasses, and thinning grayish hair that gave him a scholarly air. But he moved around in his blue jeans and boots with the light and agile step of someone who has spent years working outdoors, clambering in and out of excavation ditches, climbing up and down pyramids with surveying equipment, crawling in and out of narrow passageways. He wears a somewhat rakish green felt hat with a leather band that his academic colleagues kid him about, saying he is trying to look like Indiana Jones in Raiders of the Lost Ark.

Despite twenty-five years in Egypt and in academe, Lehner has retained his flat, plain North Dakota accent and the colloquial informality of someone who grew up in the 1960s. During his years mapping the Sphinx, Lehner would eat a stale cheese sandwich in the shade of the south side of the monument and watch as large potato chip--sized chunks of limestone flaked off and fell to the ground. The flaking is due to salt crystallization. Dew condenses on the Sphinx in the cool of the night and early morning. Salt within the stone is drawn to the surface by the moisture and dissolves. When the dew burns off during the day the salt crystallizes again, expanding greatly in size and pushing at the surface with explosive force. Sometimes as the morning dew evaporates in the sun, you can actually hear a popping sound as the salt hardens, pushing off layers of stone that then blow off in the wind. The Sphinx as it exists today, Lehner said, is in many ways no longer the same monument as it was when he began working on it: "So many of the details have changed.

" The surface modeling has sufferednot only from erosion but, in large areas, from the cement, mortar, and limestone that have been added to support and protect the statue. The Sphinx, part lion, part pharaoh, part god, stands guard over the entrance to the pyramid complex in the valley of the Giza plateau. Although gigantic for a work of sculpture--some 66 feet tall and 240 feet long--when seen from a distance it is dwarfed by the three massive pyramids that loom over it in the background, lined up in a row. Throngs of tourists thread their way along the road between the Pyramids down to the Sphinx as Egyptians in long robes follow alongside selling Coca-Cola, postcards, Egyptian papyri, T-shirts, and camel rides. Bobbing above the crowd are the brightly colored umbrellas of the tour guides trying both to ward off the desert heat and to prevent their charges from becoming separated from the group. As you face the Sphinx, the first and largest pyramid, known as the Great Pyramid, appears over its left shoulder. Standing almost five hundred feet tall, nearly eight times as big as the Sphinx, it was built by the pharaoh Khufu in about 2600 B.C.

The other two pyramids, built by his son and grandson, sit on a diagonal line in diminishing size along the ridge, creating an architectural complex that is of unprecedented scale yet surprising harmony. It is thought that these enormous mountains of stone built in the desert were meant to symbolize the ancient Egyptians'' creation myth, according to which life came into being as a mound of earth rising out of the waters of chaos, like the land rea.