The entity better known to my sons as the Coolest Museum Ever was born in 1896 in the brain of an engineer named John Stevens, who wondered publicly why Oregon’s largest city had no permanent place to collect and exhibit the state’s incredible wealth of natural resources. After about 50 years, the Oregon Museum Foundation opened its first science exhibit in a downtown hotel; the museum then moved to a house in northeast Portland for a few years before hundreds of volunteers helped build the beloved first OMSI in Washington Park, the central jewel of Portland’s greenbelt necklace.

Here millions of avid visitors proved Stevens’s conviction that a creative and colorful science museum would wow the multitudes as well as spark the imaginations (and future careers) of vast gaggles of children. By the 1980s the museum was drawing some 600,000 visitors a year, overwhelming the brick barn raised by so many volunteers, and in 1992 the new OMSI opened—fittingly, on the site of an old sawdust–fired power plant donated by Portland General Electric.

The "new" OMSI, as many Portlanders still call it, features the 200–seat Kendall Planetarium, the five–story Omnimax theater, hundreds of exhibits in its five halls, the Blueback (the last diesel–electric attack sub in operation before the U.S. Navy went entirely nuclear), and its own behind–the–scenes workshop for creating new exhibits. From its shy beginnings as a tiny natural history installation in the old Portland Hotel, OMSI now ranges across the continent and over an ocean. Its 45 traveling exhibits have delighted children of all ages in North America and Europe, its workshops inspire teachers in seven Western states, and its camps and classes fascinate kids from all over the Pacific Northwest.

But for me, all these remarkable facts and figures pale in comparison to OMSI’s greatest virtue and most subtle genius—the way it is a verb, a spark, an excitement, an incitement, for the eager, riveted, delighted children who pour through the place like a wriggling, giggling river. The secret essence of OMSI is that it never uses that word that makes children quail and shiver—oh no, Education!—yet the entire place is a cheerful college where hands–on learning activities are indistinguishable from play: folding paper airplanes and testing them in wind tunnels, clambering into a life–size Gemini capsule, creating your own meteorological forecast, meeting a real live 15–foot python (his name is Bubba, Dad!), making stop–motion films in the animation exhibit, creating your own muddy watershed, and finally, even though now you are a totally cool 10–year–old Guy draped in swagger and attitude, wandering back into Sandland, in the Science Playground where you used to spend hours when you were a little dude, a thousand years ago, and wiggling your tiny toes and dreamily building cities, while waiting, as usual when we go to OMSI, for Dad to stop staring in astonishment at the Transparent Woman.