You might think tree-ring studies seem silly and boring. But dating tree rings reveals clues about some of the world's most interesting structures and people. Stop by the West Stadium, Room 104G, today from 11 a.m. to noon and learn about applying this science to ships and schooners from the Viking Age. Dr George Indruszewski of Denmark will present "Crossdating Viking-Age Ships of the Baltic Sea" and give some clues about how they were constructed and what time frame they came from. Contact Jackie Mather at 621-1608 or e-mail her at jmather@ltrr.arizona.edu for more information.

In the spirit of the 2002 Gem and Mineral Show here in Tucson, the Flandrau Science Center will hold its first "Slab Sale" of minerals including petrified wood, onyx, agates, jaspers, native copper formations, crystals, fossils, geodes and other pieces for artisans to shape and sell or the art lover to buy and display. Proceeds from the sale benefit the science center and the UA Mineral Museum. The sale runs from 11 a.m. to 4 p.m. today at the Flandrau Science Center and Planetarium , 1601 E. University Blvd. For weekend times and more information, contact the center at 626-7827, e-mail a staff member at fsc@u.arizona.edu, or visit the Web site at http://www.flandrau.org/mineral/index.htm.

Want the skinny on just how the Mideast and the West came to be at odds? Head down to the Franklin building, Room 210 at 2 p.m. today to hear Tom Price, a former U.S. Diplomat, present "Islam and the West: A Stormy History." He will explore the history from the founding of Islam in the seventh century until today. For more information, contact Sylvia Gourdin at 621-8013 or e-mail her at sgourdin@u.arizona.edu.

THIS WEEKEND

Historically, Saturday night is a great night for high-brow entertainment - and it is no different for Tucson and the University of Arizona. Head down to Crowder Hall in the fine arts complex at 7:30 p.m. to watch the School of Music and Dance performance of the President's Concert featuring solo performers and the UA Symphony Orchestra. The performance costs $12 for the general public, $10 for UA employees and seniors and $8 for students with a valid ID. For more information, contact the fine arts box office at 621-1162 or visit the Web site at http://www.arts.arizona.edu/music.

If you're not in the mood for a concert, check out the Lesbian Looks Film and Video Series. The series is in its 10th annual season of free screenings, and features three short films tomorrow at 7:30 p.m. in the Modern Languages auditorium. Contact Beverly Seckinger at 621-1239 or visit the Web site at http://w3.arizona.edu/~lgbcom for more information.