On Halloween, the CU Wizards series will combine physics, chemistry and engineering to fascinate local children with a presentation titled "liquid crystals." Professors Noel Clark, David Walba and Joe Maclennan of the University of Colorado at Boulder and Chris Conery of Broomfield High School will teach children some of the basic concepts of liquid crystals using exciting experiments and lively visual displays. The presentation will be held Saturday, Oct. 31, at 9:30 a.m. in the Duane Physics building, room G-030, on the CU-Boulder campus.