The Mayans predicted that the world will end on December 21. Stories about the end of the world have been told since Plato wrote about the destruction of an entire continent in “Atlantis,” says Barry Vacker, associate professor of media studies at Temple’s School of Media and Communication. “What all of these stories’ scenarios have in common is that they pose the question, ‘What if?’” Vacker is participating in a celebration of the upcoming apocalypse and has written a new book on the topic.