Anyone is welcome to audit the class or sit in on lectures & discussions that may be of interest. Check the class calendar to find topics of interest to you. The only two caveats I have about sitting in are that:

1. Registered students get first priority on seats and lab resources (we've got a small class-room)
2. If you want to join us for field trips, you make your own travel arrangements (we'll only have vans with enough space guaranteed for our students).