Students and faculty build gingerbread houses at 6 p.m., AMR I, Homewood. Sponsored by Faculty Student Interaction.
The Polar Express leaves the station for the North Pole at 8 p.m. The 2004 computer-animated film is presented by HOP Friday Night Films. 50 Gilman Hall, Homewood.
Peabody faculty artist/pianist Leon Fleisher guest-conducts the Peabody Symphony Orchestra in works by Mozart, Hindemith, and Beethoven. $15/$10 seniors/$5 students with ID; call 410-234-4800. 8 p.m. Miriam A. Friedberg Concert Hall, Peabody.
Baltimore's Downtown Dollar Days come to the JHU Museums today and Dec. 9. Visitors to Evergreen and Homewood enjoy holiday music and decorations, light refreshments, gift shopping, and $1 guided tours (free for members).
Evergreen Museum director-curator James Abbott leads a workshop in the art and craft of card making in the Victorian era. 1-3 p.m. $8, free for members (includes admission, materials). Call 410-516-0341 to register.
The Octopodes gives its fall concert at 8 p.m., Bloomberg Center's Schafler Auditorium. (For the lineup of other a cappella groups' concerts, go to hub.jhu.edu/events.)
The Johns Hopkins Consortium of Health Disparities presents "Obesity Across the Lifespan: Complex Issues, Creative Solutions, a dialogue between leading experts and community leaders. 8 a.m. to 5 p.m. in the Chevy Chase Auditorium, Sheikh Zayed Tower. To register (by Dec. 5) and view agenda, go to nursing.jhu.edu/obesityconference.