John J. Collins is a professor of Old Testament interpretation and criticism at Yale Divinity School in New Haven, Conn. He is an expert on Jewish apocalypticism.

Daniel Wojcik is a professor of folklore studies at the University of Oregon. He is interested in contemporary American apocalyptic movements and groups, especially those focused on UFOs.

Sharan Newman is the author of The Real History of the End of the World: Apocalyptic Predictions From Revelation and Nostradamus to Y2K and 2012.

Dorothy E. Roberts is the George A. Weiss University Professor of Law and Sociology and the Raymond Pace and Sadie Tanner Mossell Alexander Professor of Civil Rights at the University of Pennsylvania Law School.

Sandra Patton-Imani, an adoptee, is an associate professor of American studies in the Department for the Study of Culture and Society at Drake University in Des Moines, Iowa. She is the author of Birth Marks: Transracial Adoption in Contemporary America, in which black and multiracial adoptees discuss their experiences.

Rachel Wegner is the president of Ethica, an adoption advocacy organization that works for ethical adoption practices internationally.

Trish Maskew teaches adoption law, policy and practice at American University Washington College of Law. She founded Ethica, an adoption advocacy organization that works for ethical adoption practices internationally. She wrote Our Own: Adopting and Parenting the Older Child.

Simon Martin is a Mayanist scholar and senior research specialist at the University of Pennsylvania Museum of Archaeology and Anthropology, known as the Penn Museum. Martin is co-curator of an exhibit there titled “Maya 2012: Lords of Time,” and he is co-author of Chronicle of the Maya Kings and Queens: Deciphering the Dynasties of the Ancient Maya.

Jonathan Kirsch is the author of A History of the End of the World: How the Most Controversial Book in the Bible Changed the Course of Western Civilization. He says apocalyptic anxiety has never been wholly absent from our culture, but it is at an all-time high now, due to current events and natural disasters.