''The computer age is coming.'' -- Aaron Gothelf, sixth-grader
''The computer age is HERE, Aaron.''
-- Aaron's pal, also a sixth-grader
A caravan of school buses disgorges hundreds of elementary students outside this limestone palace 100 yards from Lake Michigan.
Taller visitors struggle against the current of faces and shrieks. They crush through choked doorways and fan toward beckoning marquees: ''Calculating to Computing,'' ''The Money Center,'' ''Technology: Chance or Choice?'' ''Telecommunications.''
This is an amusement park of science and technology, where the arcades, rides , and midway make kids and adults willing captives to these often obtuse or outwardly daunting subjects. The amusements - sideshows of turning cranks, gears , and push buttons - are really hooks to bigger things. They are ways to help all ages ''attain basic public science literacy,'' say the founders, about the technologies that increasingly embrace our everyday life. That means finding entertaining ways to strengthen our grasp of scientific principles, applications , and social implications.
Heavy words but fun stuff here at the Chicago Museum of Science and Industry. Descend into a ''real'' coal mine, tour a captured German sub, examine the Apollo 8 spacecraft, browse through room upon room of machines, computers, trains, planes, cars - old, new, and futuristic.
And like carnival barkers who cajole you as you weave toward the main attractions, robots talk, machines ask questions, and moving boards flash quizzes that beg for answers. The idea is to engage the museumgoer beyond his natural reticence or classroom-learned passivity.
These excited sixth-graders say they've all been here many times before, and not just on school field trips. Do they really learn from all these cranks, buttons, and levers? A sea of heads begins to nod.
Why is it important to come to a museum like this? they are asked.
''The computer age is coming,'' says 41/2-foot-tall Aaron Gothelf, from the Riley Elementary School. He beams from behind a set of sparkling braces. ''The computer age is here, Aaron,'' corrects a puckish pal inciting the class to giggles.
These kids are aware of the new technologies - computers, electronic games, advances in telecommunications - trickling into their homes, schools, and entertainment places. And at this early age they are getting an introduction to what came before, what exists now, and what will come. And perhaps more important, they are being taught to ask, ''What are the cultural side effects?''
''The public has had little opportunity,'' says David A. Ucko, science director at the museum, ''to examine in perspective the impact of modern technology. Such an omission has special significance for young visitors who cannot evaluate from personal experience how different technological choices in the past may have changed the present.''
Back when museums were solely historical collections of objects arranged chronologically behind and beneath glass, the concept of a ''hands-on'' museum was brand new. That concept - three-dimensional, participatory exhibits that are fun - originated in 1933 in this very building, an abandoned relic from Chicago's 1893 Columbian Exposition. This pioneer of experiential museums has spawned brothers, sisters, and cousins as well in such far-flung locales as Columbus, Ohio; Toronto; San Francisco; and Los Angeles.
One lifelong fan of the museum says she owes her high school graduation to the clear, simple, and fun exhibits. ''I did not like physics at all,'' she says , ''but I used to bring my workbooks to the museum and do my assignments. I could walk through the exhibits and find things out I could never understand otherwise.''
Celebrating its golden anniversary this year, the museum has adopted a slogan - ''For 50 years, a Celebration of the Mind'' - and an itinerary of events, conferences, dinners, and celebrations through next fall. And they've planned new hands-on exhibits to continue the educational legacy they started in the depression. Some of the museum's more popular exhibits:
* ''The Money Center'' is an imaginative arcade of economics at work, showing the function of money and banking through the use of computers, puppets, barter games, and shopping sprees. One highlight is Philosophers' Park, where the theories of economists - Keynes and Smith, for example - are traced.
* ''Omnicom'' presents the story of telecommunications, from the first telephone by Alexander Graham Bell to the latest in satellite technology. Here the visitor is offered an array of space-age gadgetry, including a game of electronic tic-tac-toe.
* ''Nobel Hall of Science'' honors the 139 American scientists who have been awarded the Nobel Prize in physics, chemistry, and medicine. Bright displays and visitor-participation units tell of the scientists' achievements and how their work has contributed to the development of these fields.
The museum has produced two special exhibitions specifically for the anniversary. One entitled ''Technology: Chance or Choice'' examines the impact of computers, television, and nuclear energy. The other, ''A Half Century of Progress,'' traces the history of the museum. It was founded by Julius Rosenwald , a noted Chicago businessman and philanthropist, who was inspired by the Deutsches Technical Museum in Munich, Germany, during a 1911 visit with his young son.
About the time Rosenwald was offering $3 million to leaders of the city, a civic move was under way to rebuild the old Palace of Fine Arts, the sole remaining structure of the Columbian Exposition. A deal involving the use of the building was closed in 1926, but the museum did not formally open until 1933.
The museum is an independent, nonprofit institution. Many of the exhibits are presented as a public service by industrial companies, trade associations, professional societies, government agencies, and foundations. Others are developed by the museum staff.
Lynette Singleton of the Goodlow Elementary School likes talking on the early and modern telephones to hear how her voice sounds when played back. She also likes talking into an oscilloscope to see that speech is made up of waves. Her friend Katrina Washington loves the glass incubator through which visitors can watch baby chicks peck out of their shells. Another girl, trying to match sounds with a computer, finds out that sound is measured in frequencies of waves called hertz. The machine tells her the tone she produced is only 10 or 12 hertz away from the one produced by the machine. A screen lights up ''Good Match.''
Another exhibit takes you through the history of petroleum. It makes a giant impression on you when your own, private, shell-shaped car shimmies around a corner to be confronted by a round, 10-to-15-foot glowing sun. A recorded voice explains that this is the source of all the earth's fossil fuels, since it creates the vegetation that eventually winds up as peat, coal, oil, and natural gas. Rooms full of appliances show that America is not only the greatest consumer of this energy, but also the greatest producer of products. Final exhibits make poignant how crucial conservation is.
One long line waits not for a roller coaster but for a type of cable car that drops riders into a full-size replica of an actual southern Illinois coalfield. Inside are real walls of coal, coal cars, and machinery. Tour guides explain how it all works.
Winding through the museum's labyrinthine halls on the way to exhibits, you pass displays you thought you didn't want to see. This sort of window shopping through the wonders of science can be surprising.
How fascinating can the history of hardwoods be? Two equal-size blocks of wood show that one, balsa, weighs eight pounds, the other, lignum vitae, 78 pounds. You stand next to a globe and push buttons next to names for woods you've never heard of. A bulb in New Guinea lights up. Next, three in Australia. Another exhibit shows how the wood ends up in Queen Anne, Louis the XIV, French colonial, and other styles of furniture.
Not everything works or is immediately understandable. Leonardo da Vinci's wave compression machine, with a hanging Slinky toy to illustrate wave motion, is on the blink this Monday. So is Robert Boyle's ''sound vs. compression waves.'' Next comes a sign, ''Turn wheel to see how sound waves interact.'' One boy from Quincy, Ill., turns the crank. A translucent plate of glass with concentric circles overlaps another. ''What did you learn?'' he is asked. ''Nuthin'. But it's still fun.''
Another exhibit is thoroughly baffling. ''Turn crank to see how magnetic bubbles store information,'' said the sign. Doing so produced an almost unnoticeable influx of light into bubble shapes in glass. Since there are so many fun cranks to turn, visitors are often inclined to bypass exhibits requiring too much reading of charts to understand the principles being displayed.
And there is also the specter of hundreds of energetic bodies bouncing from exhibit to exhibit, pushing buttons to start recordings or movies but then leaving them well before they've run their course. Or turning cranks for the fun of it, but not bothering to examine the significance.
But overall the Museum of Science and Industry seems, if not totally ideal for learning, at least a welcome respite from what can become the drudgery of the classroom. From the teacher's point of view, how has the experiential concept fared in its five decades of operation?
''Yes, they learn a lot,'' says a teacher from Madame Curie High School. ''Everyone finds something they like, and they always have more questions and a general attitude of inquiry and a desire to learn more when they leave. It gives them ideas. Some are fascinated. Others are fascinated more.''
A brief look at the schedule of coming events for the 50th anniversary:
* Anniversary dinner on June 8 at which founders, longtime exhibitors, and major donors will be honored by the museum.
* ''Science Jubilee,'' a three-day outdoor birthday party on July 15-17, that will feature the Chicago Air and Water Show, special exhibits, a ''Science Midway,'' a circus act, and ''Up With People.''
* An international conference on the role of science and technology museums in furthering science literacy, Oct. 16-18.m