Cai Guo-Qiang is a master of the momentary. His eternity is found not in an hour but in a flash.

Best known for his spectacular fireworks displays at the 2008 Beijing Olympics, Cai is in Philadelphia for tomorrow's presentation of a huge fiery flower that will soar 90 feet into the darkening sky over the Philadelphia Museum of Art and, a bit later, for a smoldering indoor event at the Fabric Workshop and Museum on Arch Street.

Gunpowder drives the whole, a reflection on memory and time's inexorable passage, and an hommage to Anne d'Harnoncourt.

At the Art Museum, sometime between 4 and 4:30 p.m., Cai's Fallen Blossoms: Explosion Project will lift off, flaming into the sky to form a vast, quickly fading flower.

At the Fabric Workshop about 6 p.m., he will finish drawing - with sprinkled and poured gunpowder - his Time Scroll and ignite it. The riverlike scroll, set in a serpentine steel trough neaarly 100 feet long, will flame up intensely, burning an image into its silk backing.

The image will sink into the water of the trough and, over the next three months, slowly wash away - finally leaving only a memory of itself.

The initial images themselves will be inspired by memory - recollections of Marion Boulton Stroud, known as Kippy - of her four-decade friendship with d'Harnoncourt, the head of the Art Museum, who died unexpectedly last year.

Stroud is the founder and force behind the Fabric Workshop, and it was in conversation with d'Harnoncourt six years ago that the two agreed to collaborate and bring Cai to Philadelphia.

"Cai has brought everything together like a symphony," Stroud said the other day. "He's been spectacular."

Tomorrow's blazing events are not the only elements in the collaboration.

In addition to Time Scroll, the Fabric Workshop will present five weavers from Hunan province's Xiangxi region, who will set up looms on the workshop's seventh floor, one floor below Time Scroll. Over three months, they will produce tapestries based on Stroud's spoken d'Harnoncourt recollections.

The record of this intense friendship will be stitched into cloth - the work has been dubbed Time Flies Like a Weaving Shuttle - much as memory is stitched into experience.

The Art Museum will also host Light Passage, an exhibition of Cai's large gunpowder drawings - the burnt residue of ignition - representing a meditation on time and the passage of the seasons.

"I want to express the fragility and transient beauty of the flower, gorgeous when it blooms, great beauty," Cai said, following a successful test firing last week of his Fabric Workshop river drawing.

"But the flower also perishes very quickly," he continued, discussing his Art Museum "explosion event." "I was fascinated by the idea of using a very violent force to create something that is fragile and delicate."

Cai, 52, has lived in New York since 1995; he was born in Quanzhou City, Fujian province, China, and moved to Japan in 1986 to study. He has won the Golden Lion at the Venice Biennale, the Hiroshima Art Prize, and the 20th Fukuoka Asian Culture Prize, and was the subject of a retrospective last year at New York's Guggenheim Museum.

During the test firing at the Fabric Workshop - conducted last Friday for the city's fire marshals - Cai spent time contemplating the ribbon of steel running the length of the Fabric Workshop loft, then sketched with dribbles of powder what he called "a simplified" rendering of Time Scroll - quick stick figures, Chinese characters, suns, a simplified Art Museum facade, flowers.

Dozens of people milled around, but he remained completely focused on his piece.

"This is a test to see how much smoke will be generated," he told everyone. "The smoke will rise and then slowly come back down. The last time, there was lots of smoke and it took way too long to clear." (Cai speaks English but used his project manager, Chinyan Wong, to translate his comments to the crowd and during an interview.)

At 2:39 p.m., he lighted the southern end of his drawing. There was a whispering "poof," and fierce yellow-and-white flames burst up several feet, then slowly and erratically burned along the silk the length of the trough. Clouds of smoke rose toward the ceiling and, as predicted, slowly drifted down.

The entire drawing burned out in just about two minutes. Exhaust fans at the back of the room started blasting, and front windows were opened. The room was clear of smoke in less than eight minutes.

Left on the scroll was a delicate drawing, something very much akin to traditional Chinese ink drawing.

"When I started exploring using gunpowder in China, it was a very simplistic exploration on canvas or on paper, and it was a liberation for myself," he said. "But when I moved to Japan in 1986 to 1994, I was using gunpowder a lot more for land art, so that I could have a personal dialog with the universe or with nature.

"When I moved to the States in 1995, I used Chinese gunpowder to have a greater social dialog. . . . In the West, gunpowder is no longer useful for liberating myself, rather it's a tool for creating social dialog or reflecting on the conditions of contemporary society."

For his Philadelphia piece, he explores ancient themes of time, memory, death - and the "fragile bonds of life."

"I wanted to use this opportunity to explore the meaning of friendship and to use nostalgia and passage of time and take this opportunity to elevate the show to these more humanistic themes," he said.

For Stroud, whose taped recollections will also play at the museum (as will a slowed-down video of the Art Museum's exploding-flower event), the sheaf of exhibitions provides an opportunity to think about her friend and what they shared - travels, apartments, flat tires, lost earrings, parties, conversations.

"Cai has been so brilliant weaving together his own work and memories of Anne," said Stroud. "His work is just beautiful."

Boom! Flash!

Cai Guo-Qiang's public "Fallen Blossoms" explosion will take place on the Philadelphia Museum of Art's East Terrace between 4 and 4:30 p.m. tomorrow.

An exhibition preview for Cai's "Time Scroll" at the Fabric Workshop and Museum, 1214 Arch St., begins at 5:30 p.m. tomorrow. The drawing

on silk will be ignited

at 6 p.m. There is a $1 admission charge. EndText

Contact culture writer Stephan Salisbury at 215-854-5594 or ssalisbury@phillynews.com.