These are the closing days for “Sometimes Time Trembles,” an exhibit by Cantabrigian Suara Welitoff that pulls images and video from the past and loops and twists them into something fresh and thoughtful.

We’re used to film loops. We call them gifs, and they’re funny because they have celebrities acting out, people making pratfalls or cats and dogs doing what cats and dogs do, each within a few seconds we can watch over and over without much energy expended to think about what’s happening within.

But none of the loops in Welitoff’s exhibit are gifs that make a point or give us a laugh, and that puts them in a completely different genre.

Thanks to what is nearly a complete generation of fictionalized found-footage filmmaking – “The Blair Witch Project” came out in 1999 and has birthed so many children the crankiness of the title character is understandable – it’s nearly inevitable that art such as Welitoff’s gets layered with meaning and placed in a genre the artist might not have intended. But one suspects it’s welcome even so, since it results in a rapt audience.

“Blair Witch” and “Paranormal Activity” and the rest of found-footage horror has underlined our need to beware the slow-moving past we could once arrogantly think we’d left beyond. We’re trained to think we have to explore it for the evidence we need to figure out what’s going on right now, and the genre specializes in tedium that lulls us into shock when something finally happens (see the “Paranormal Activity” series, or don’t) and embedding details we rely on for our survival (see “The Ring,” in which grainy video of the past literally reached out to threaten the watcher).

So what’s riveting in “Sometimes Time Trembles,” a title with a real-life horror feel if ever there was one, is that, well, nothing happens. Welitoff’s “Five Years Later” video loop with clouds makes that as plain as anything could, but it’s a warning we can’t heed. We keep watching the chalkboard loops of “untitled (spiral)” and unendingly preparatory throat-clearing of “Interview” because we can’t look away without missing what happens. It might happen the 10th time we watch or the 100th. A blip we reject as a video glitch on the seventh viewing might keep growing until it takes over the screen on the 70th. You never know.

The Boston Globe likes the exhibit too, saying it “makes familiar visual tropes fresh, affirming that we will always find something new in the past, if only we know how to look.”

Welitoff is a Cambridge resident with works in collections at the Museum of Fine Arts and the deCordova Museum Biennial.

“Sometimes Time Trembles” runs through Saturday at the Barbara Krakow Gallery, 10 Newbury St., Boston. It is open 10 a.m. to 5:30 p.m. daily. Call (617) 262-4490 or click here.