I somehow doubt that the students sipping lattes outdoors at the Metropolitan Bakery in University City know they are sitting just steps away from the Slought Foundation, Philadelphia's most ardent supporter of the avant garde, a gallery-cum-symposium space near the University of Pennsylvania that has been proudly showcasing the brainy, the esoteric, the radical, and the resolutely noncommercial since its opening in 2002. To be fair, though, the Slought doesn't even look like it's open today, with that piece of raw plywood over its door.

Turns out the Slought Foundation is alive and well, if you dare turn the doorknob. Never mind that once in, you find yourself plunged into darkness (the point of the plywood is now clear). Within seconds, though, your eyes adjust to the only two sources of available light, which are two camera obscura projections at either end of the room.

Richard Torchia's installation, Grotto, has transformed this otherwise ordinary, low-ceilinged room into a mysterious, amorphous space. At the Walnut Street storefront end, the constantly moving pedestrians, trees and cars outside are projected onto the inside of the frosted glass of the front windows; at the other end, an eerie projection shows dripping illuminated water, as if someone had shone a flashlight into the interior of a cave. Torchia's makeshift cameras, which consist of two lenses positioned at either corner of Slought's storefront, and an actual pinhole camera mounted over a utility sink at the back of the room (hence the dripping water), capture real, everyday images in real time, but they look strangely evanescent, as if delivered by seance.

In the other gallery, which is lit, the poet and artist George Quasha is showing stone sculptures that at first look somewhat conventionally beautiful by Slought Foundation standards. They are not remotely ordinary, as it happens. Each individual sculpture consists of two large rocks that appear to be bolted or somehow otherwise joined in their unbelievably precarious unions, but that are, in fact, painstakingly balanced by Quasha (he perfects the rocks' balancing act at his home in New York state, then rebalances them for exhibitions) in a state he calls axial, "which presents them at the horizon of their own event." I'd call them perilously sublime.

Slought Foundation, 4017 Walnut St., 1 to 6 p.m. Thursdays through Saturdays. 215-701-4627 or www.slought.org. Suggested admission $2 adults; $1 students and children. Through May 23.

What, this old thing?

It used to take a decade or two for functional objects to enter the design canon. Now that stores such as Target and Ikea have made design affordable and eBay has made it profitable, however, buying yet another OXO utensil or Swatch watch is simply a smart investment. Or so would say architect and home-furnishings designer Lisa S. Roberts, part of whose collection of relatively youthful design icons can be seen in "Antiques of the Future" at the Design Center at Philadelphia University.

Roberts, whose collection is accompanied by her new book of the same name (Stewart, Tabori & Chang; $29.95), began buying design objects 25 years ago. The 97 pieces on view here, which represent slightly less than a third of her collection, range from furniture to accessories to domestic and office gadgets.

Most of the objects in the exhibition, such as Michael Graves' 1985 Whistling Bird Tea Kettle, Jonathan Ive's 1998 iMac, and those limited-edition Swatch watches, are obvious future antiques, though it's fun to see them displayed here, anyway. It's the occasional oddballs, like the Orbitz soda bottle (with its distinctive clear soda featuring floating colored balls), or the Rubber X-Bands (by an unknown designer but featured in MoMA's 2004 "Humble Masterpieces" exhibition), or Fernando and Humberto Campana's 2003 Favela Chair, constructed from found scraps of wood and therefore unique, that add verve to Roberts' collection.

The Design Center, Philadelphia University, 4200 Henry Ave., 10 a.m. to 4 p.m. Mondays through Fridays. 215-951-2860 or www.philau.edu/designcenter. Through June 25.