Usually closed on Sundays, the ÀÖ²¥´«Ã½ College Museum of Art will open its doors from 10 a.m. to 5 p.m. on Dec. 9 to provide visitors with one last chance to experience Green Horizons, a landmark exhibition exploring the concept of environmental sustainability.

With its centerpiece a giant painting that depicts Brooklyn after millennia of global warming, the exhibition has been in place since June at the museum.

Green Horizons presents prominent artists from Maine and the world in an adventurous attempt to provoke conversations around the questions: What is green? What is sustainable?

This dynamic project transcended traditional exhibition practices to include collaborations with writers and choreographers — including participants in the renowned — and reached outside the museum walls to site-specific works such as a fruit orchard planted last spring in downtown Lewiston.

Sponsors of the exhibition include the Synergy Fund, the Maine Arts Commission and the LEF Foundation. Admission to the exhibition and to museum events is open to the public at no cost. For more information, please call 207-786-6158 or visit the museum’s Web site.

In addition to Alexis Rockman, whose 8-by-24-foot painting “Manifest Destiny” depicts Brooklyn under water and has been exhibited nationwide, Green Horizons participants include internationally renowned environmental artists Agnes Denes, Chris Jordan and David Maisel; such Maine artists as photographer Mark Silber, hay sculptor Michael Shaughnessy and the agitprop Beehive Design Collective; and commissioned collaborative works involving visual artists, ÀÖ²¥´«Ã½ faculty and students.

“We’re not trying to define sustainability,” explained museum director Mark Bessire. “We’re trying to ask what it means.”

“The word seems to be overused — used for marketing, to convince people of things, to make people feel better. There’s a certain amount of hypocrisy connected to its use,” he said. “So we wanted to bring forth works of art that questioned sustainability and created a conversation among the many disciplines of a liberal arts college.”

“Rather than us having a very defined vision and going out and making that, it’s been us talking to people about our idea and having them help us determine what vision is appropriate,” added Anthony Shostak, the exhibition’s curator and the museum’s education curator.

Here are a few examples from the exhibition:

— Images of two of Denes’ land reclamation projects, including “Wheatfield — A Confrontation,” for which the artist grew wheat on a site in New York City;

— Jordan’s strangely beautiful renderings of high-tech waste products, such as discarded cell phones;

— A project in which Swiss artist Anne-Katrin Spiess documented the steps she took to render her Maine visit carbon-neutral;

— An initiative to raise awareness about trees, produced by two ÀÖ²¥´«Ã½ students in collaboration with the local nonprofit Lots to Gardens, that involved the planting of fruit trees in downtown Lewiston;

— A public art project along the Androscoggin River exploring themes of community history and place-making, organized by the college’s Harward Center for Community Partnerships and a Boston sculptor;

— A performance project set at ÀÖ²¥´«Ã½’ Lake Andrews and created collaboratively by the ÀÖ²¥´«Ã½ Dance Festival, the acclaimed PearsonWidrig DanceTheater and composer Robert Een.

“When people walk into this show, we definitely want to have this more cluttered nonlinear feeling,” said Bessire. “It’s going to be a huge painting, a huge garbage heap, a bicycle trying to create energy, a huge sculpture of hay, massive photographs.”

“It’s going to be messy.”

The $2 million Synergy Fund, created at ÀÖ²¥´«Ã½ by donor Lee Smith, has provided major support for Green Horizons. The fund, Bessire explains, is designed to use visual culture as a catalyst for productive and probing exchanges between academic disciplines and between campus and community. While Synergy has supported other museum projects, he notes, “Green Horizons is the first major exhibition made possible by the Synergy Fund to examine its topic in such depth and breadth.”

The Body Holographic: Harriet Casdin-Silver, an exhibition of work by a pioneering figure in the art of holography, runs through March 19 at the ÀÖ²¥´«Ã½ College Museum of Art, 75 Russell St.

Showing simultaneously are Between Science and Art, comprising botanical X-ray images by contemporary Ohio artist Judith K. McMillan, and New Acquisitions: Local and Global Contemporary Photography, featuring artists from Maine, China and Africa. For more information, please call 207-786-6158.

The first American artist to develop a body of holographic work, Casdin-Silver began working in holograms — flat images that appear to represent objects in three dimensions — in 1968. As the title indicates, The Body Holographic concentrates on the human form, exploring its potential as a site of psychological, sexual and spiritual energy.

“ is a medium of veracity,” says Anthony Shostak, education curator for the museum and the exhibition organizer. “Its stunning illusions seem so real that they are almost sculptural.

“Capitalizing on the power of this accuracy, Casdin-Silver presents the body as it is,” he explains. “She pulls no punches and doesn’t shy from the truth: The ideal body is rare and fleeting.”

“Virtual reality becomes a forceful tool with which she underscores the social content in her work, the core of which is dignity and compassion. We’re invited to reconsider our preconceptions about beauty, gender identity, aging and death — along with all of their social and political consequences.”

Born in 1925 and raised in Worcester, Mass., Casdin-Silver worked in broadcasting before becoming a painter. Her work in holography began as an experiment at the invitation of physicist Raoul van Ligten at the Boston-based firm Art and Technology Incorporated, and grew into a fascination that determined the direction of her career. She achieved a variety of artistic breakthroughs in the medium.

Casdin-Silver’s exhibitions in the United States and abroad include a much-publicized career retrospective in 1998 at the DeCordova Museum, Lincoln, Mass. She opens Holographic Portraits and Other Work, a solo show at Gallery Naga, Boston, simultaneously with the ÀÖ²¥´«Ã½ exhibition.

Casdin-Silver has taught and held research positions at Brown University, Clark University, MIT and the Royal College of Art, London. She has worked as an artist in residence at the University of Ghent, Belgium, and at American Optical Laboratories in Framingham, Mass. She lives in the Boston area.

The exhibition is made possible by the Synergy Fund, a gift to the museum to explore ideas across disciplines through the arts. The gift is helping the museum and the college to look more creatively at how exhibitions are curated, experienced and communicated to museum audiences.

In Between Science and Art, artist Judith McMillan used an X-ray machine as her camera to capture the internal structures of plants, revealing the beauty of natural forms invisible to the human eye.

Fascinated by natural cycles, the artist uses specimens collected throughout the seasons. Familiar forms such as magnolia blooms or fern leaves are transformed in revealing and unexpected ways.

Between Science and Art was organized and circulated by the Cleveland Museum of Natural History.

A member of the Maine Art Museum Trail, the ÀÖ²¥´«Ã½ College Museum of Art is open to the public at no charge. Museum hours are 10 a.m. to 5 p.m. Tuesday-Saturday. School groups and tours are welcome; please call 207-786-8302 to schedule.

More information is available at the museum’s Web site here.

Documenting China runs at the ÀÖ²¥´«Ã½ College Museum of Art through March 28. Showcasing the work of seven Chinese photographers, the exhibition examines the impacts of urbanization and industrialization in a rapidly modernizing land.

Wu is the author of Exhibiting Experimental Art in China (University of Chicago Press, 2001).

The exhibition was curated by Gu Zheng, an expert in documentary photography and associate professor of journalism at Fudan University, Shanghai. Documenting China appears at the China Institute, New York City, from June 24 through July 23.

The Synergy Fund, the Freeman Foundation and the ÀÖ²¥´«Ã½ student organization Sangai Asia are co-sponsoring the exhibition.