In the future, science will be able to produce a Steven Spielberg movie without any awe. The future is now! “Tomorrowland,” from animation whiz turned live-action director Brad Bird (“The Incredibles,” “Mission: Impossible — Ghost Protocol”), is a square-jawed, optimistic, all-American sci-fi adventure with a kid protagonist and George Clooney, for heaven’s sake. With more heart and less pontificating, it could have been one for the ages.

In Florida, Casey Newton (Britt Robertson), a teenage science buff with a surplus of curiosity, finds a World’s Fair souvenir that gives her a glimpse of Tomorrowland, a gleaming alternate dimension of jet packs and futuristic marvels. Together with Frank Walker (Clooney), who’s also been to Tomorrowland, and Athena (Raffey Cassidy), a young girl who recruits scientists and dreamers to work there, Casey must learn Tomorrowland’s secrets, save the world, et cetera.

The journey is mid-grade fun, occasionally thrilling (there are bad guys chasing them), yet strangely unsentimental, promising a “gee whiz, look at that!” sense of amazement but mostly delivering on-the-nose speeches about mankind’s duty to build a better future. And the way it’s structured (Bird co-wrote the screenplay with “Lost” creator Damon Lindelof), we don’t know what the main characters’ objective is till the film is nearly over — which makes it hard to keep caring. The central performances are likable, but though the film has some wonderful things in it, it’s not full of wonder like it ought to be. You may find that you like its ideas more than you like it.

B- (2 hrs., 10 min.; PG, mild sci-fi action and peril.)