Few things are sadder than a good idea badly executed. Knowing seems to have a good idea at its core. If it had a talented writer and a skilled director who knew how to make the impossible look plausible, it might have been a true classic. Instead, burdened with clunky dialog, indifferent acting and cheezy digital effects, it drifts into the territory of “unintentionally funny.”

Back in 1959 the administrators of an elementary school decided to bury a time capsule to be opened 50 years later. The kids were told to draw pictures of what they thought the future would be like, to be put in the capsule. Instead of drawing a picture, a spooky girl named Lucinda covered her paper with a long sequence of numbers.

Now in 2009 the capsule is dug up. The paper ends up in the hands of John Koestler (Nicolas Cage), an astrophysicist from M.I.T. whose lectures sound like they were prepared for an audience of fifth graders. He figures out that the numbers encode the dates and locations of all the major disasters that have occurred in the intervening 50 years, plus a few that haven’t occurred yet. So of course he has to prevent the remaining disasters from happening, assuming that is possible.

Few actors are better than Nicolas Cage at conveying internal torment and suffering, although in this case I can’t help wondering if he is tormented by the lines he has to deliver. The other actors are less expressive. In some cases the word “wooden” comes to mind. The flashy special effects are so obviously computer-generated that I was left with no feeling of emotional involvement, even while watching disasters. All in all, a disappointment.