You can call "Interstellar" corny or reiterative or just plain daunting, and you'd be right. It is those things. It is hobbled by astronomy and physics seminars disguised as dialogue. But even with its vividly realized imaginings of journeys through a worm hole, or its depiction of the largest tidal wave in the history of water, what I remembered first the following morning was this: Matthew McConaughey's character crying his eyes out as he watches years and years of backlogged video messages left by his son back on Earth. Simple, elemental human feeling. More directors should try it sometime.

Co-written by Jonathan Nolan, Christopher's brother, the film is caked with the dust of death and bereavement, yet it posits that love is stronger than gravity, relativity, and even ordinary blockbuster imperatives. "2001: A Space Odyssey" may be the director's touchstone, but Nolan's own galaxy quest is as warm and fuzzy as Stanley Kubrick's vision was stoically indifferent to the plight of humankind.

The starting point is conventional enough. We're on a farm somewhere in America (played by locations in Alberta — apparently the Canadian tax breaks never end). The only crop is corn, and the so-called "blight" has ravaged the global food supply. The planet's time is nearly up. McConaughey plays Cooper, a frustrated farmer trained as a test pilot who lives with daughter Murph (Mackenzie Foy), son Tom (Timothee Chalamet) and father-in-law Donald (John Lithgow, whose stage-trained diction makes the naturalistic McConaughey drawl all the more pronounced). One of the upstairs bedrooms, lined with bookshelves, appears to be haunted by benign, book-tossing ghosts. Surely there's an explanation.

One night, somewhere near their homestead, Cooper and Murph stumble onto the secret underground location of what's left of NASA, where a project headed up by the eminent Prof. Brand (Michael Caine, Nolan's go-to purveyor of mellow wisdom) intends to find a home for Earth's inhabitants before the clock runs out. Cooper qualifies as the right flyboy for this crucial space exploration mission. Destination: a wormhole near Saturn. On the other end of the wormhole, what? A new home? A new set of troubles?

The film takes the time and the narrative space to explore several worlds. One is wet, dominated by inhospitably crushing mountain-sized ocean waves; another is pure ice, where even the clouds above are snow chunks. In one of the script's more usefully provocative notions, time on the water-logged planet proceeds at seven years per human hour. I love this bit; it's instantly graspable, and frightening, cutting to the heart of Nolan's obsession with time lost, time spent and misspent. This goes back to "Memento," a fleet-footed brain-scrambler from the other end of the wormhole of this filmmaker's career.

Every temporal aspect of existence bends and twists in "Interstellar." There's not much room for the usual conflict and resolution, and for a daring portion of the film Nolan manages to make a sincere science-fiction epic without an antagonist, only a tangle of conflicting intentions. As adults, Cooper's children are played by Jessica Chastain and Casey Affleck, and as they age back on Earth, Cooper wonders if he did the right thing leaving them (not really a moral dilemma — the fate of the planet's hanging in the balance), or if he'll ever see them again.

How these questions are answered in the film's final 45 minutes will likely toss half of any given audience right off the bus. I sympathize. Yet I found myself hanging on, through the film's several endings, and even the endings beyond those endings. This is a movie unabashedly earnest in its intention to awe. It's certainly the first science-fiction film to combine relativity theory with a line about burying grandpa "out in the back 40." The Nolan brothers' screenplay asks only that we, the awed, or the partly awed and partly confused, embrace family and our time on Earth, or wherever we end up. It's the same plea made by writers as diverse as Charles Dickens and Thornton Wilder. While I devoutly wish Nolan had sent composer Hans Zimmer and his droning, thundering score into deep space, I'm glad we live in a world where a fabulously successful director can retain his ambition, even at the expense of clarity.

Sixty-six minutes of "Interstellar" were filmed with 70 millimeter Imax cameras; all of it was filmed on celluloid, as opposed to digitally, and the visual results carry a rougher, grainier quality than you typically see in space epics. The same is true of the movie's most nakedly expressive scenes, which have nothing to do with how special the effects are (and they're pretty special). When McConaughey breaks down watching years-old messages from his son, he weeps. And even Zimmer's music backs down, allowing the scene to breathe, play out and — like the best of this crazy, mixed-up, heartfelt endeavor — matter.