In the popular Harry Potter series of novels, the boy wizard often uses an invisibility cloak he inherited from his farther. Atlanta high-school senior Julia Abelsky is working to make such vestments a reality. NASA hopes to return Americans to the moon and eventually build a permanent colony. Junior Sergio Parra from Auburn is working to make that cheaper by making concrete from materials on the moon’s surface. Both students are competing this week at the Intel International Science and Engineering Fair in Phoenix.