Invisible forces became visible Friday afternoon as Center School students got a lesson in electromagnetism through several experiments.

Christina Moscat of the Museum of Science in Boston visited the school to give third graders an understanding of positive and negative charges and what materials can conduct electricity.

The first experiment had Corinne Roberts “unbalancing” the charges on Lily Galary’s head by rubbing her hair with a balloon.

As negative charges jumped to the balloon, Corinne got Lily's hair to stand on end.

“I'm messing up your hair for science!” said Moscat.

She also had several students link arms while she passed on static electricity generated through a Van de Graff machine, illustrating that electricity can travel though a “human extension cord.”

The program was part of the museum's traveling programs and was sponsored by the Mattapoisett PTA.