In the beginning, someone asked "where?"

And, according to a new exhibit at the National Geographic Society, someone else answered by using a stick to scratch in the dirt, thus making the world's first map.

Soon, the world and the universe may be charted on floppy discs for home computers.

Humans began to measure and map the universe from the beginnings of civilization, and have yet to complete the task. The great history of that effort is told in 500 photographs in an exhibit, open for the next six months at the National Geographic Society, 17th and M streets NW.

The U.S. Geological Survey (USGS), which produces 1,500 different maps a year, and the Geographic, which makes 60 to 90 a year, are sponsoring the exhibit to mark the 100th anniversary of Maj. John Wesley Powell's plan to map the United States topographically. (Powell was the second director of the Geological Survey and a founder of National Geographic.)

"Powell told Congress the mapping could be accomplished in 24 years--quicker with larger appropriations," said R.B. Southard, chief of the Geological Survey's national mapping division, at ceremonies recently at the Geographic. "Today, USGS is still trying to complete Powell's vision of complete topographic mapping of our country. So far about 96 percent of the country is mapped at the scale of a mile to an inch or larger."

According to the exhibition, the USGS has made "nearly 50,000 different topographic maps of every hill, stream, hamlet and forest of the United States."

As for the future, Dallas Peck, USGS director, pointed out, the exhibit shows "how far we have come in our quest to know where we are, to extend 'that abstract science of geographic art'--map-making--into the cosmos."

USGS expects to use "optical disk mass-storage systems to store all information contained on 50,000 standard 1:24,000 scale topographic maps on 4,000 thin plastic discs which will fit into three or four standard size filing cabinets," Southard said.

Southard said the USGS already uses satellites for mapping and computers to store information. Gilbert M. Grosvenor, Geographic president, said the society already has bought a Scitex computer cartographic system and is putting 250,000 names on a data base. "We are on the edge of a breakthrough in mapping with the use of video discs, lasers and satellites. In five years, we'll have to completely revamp this exhibit."

The first map produced on the Geographic's own computer will be of Jamaica, in the June issue, said John B. Garver Jr., chief cartographer.

Earlier maps, made by hand, not computers, and shown in the exhibit's panels of photographs, are intricate and varied. Greenland Eskimos carved wood and ivory maps to show coastlines. Marshall Islanders made sea charts out of palm and coconut fibers. The earliest maps, from Mesopotamia, are made of clay tablets or boundary stones, both topographic and cadastral (showing property ownership for taxation). The Egyptians even made road maps for the afterworld. Eratosthenes measured the circumference of the Earth in the 4th century and was only 200 miles off.

A map of Constantinople in 1420 from "The Book of Islands" shows a domed mosque, towers and the city walls. A world map by Ibn Said in the 13th century shows an amalgamation of Arabic and European cartographic methods. Map makers of the Renaissance tucked in elephants and sea monsters and Prester John whenever they ran out of known features.

Closer to home, the exhibit notes that George Washington, Benjamin Franklin, Paul Revere and Daniel Boone were all surveyors. Surveys and auctions were responsible for America being divided into checkerboards, rather than following topographic features as in Europe.

Aerial photography began with balloons in 1858, but the first photogrammetry on a large scale came in the 1930s with the Tennessee Valley Authority. The first satellite view came in 1957. In 1969, the astronauts of Apollo 11 landed on the moon on a site accurately mapped on Earth.

The exhibit, designed by Ann Chaparos with captions by Laura Greenberg, will tour science museums after it leaves the National Geographic's Explorers Hall. The exhibit is open 9 a.m. to 6 p.m. daily, 9 to 5 on Saturdays and 10 to 5 on Sundays.