Neil deGrasse Tyson hosts this science newsmagazine:

Epigenetics - It seems the environment in which we live makes small chemical changes to our DNA without affecting our genes' overall makeup. Experiences may trigger these switches and turn genes on or off. These subtle changes can then be "remembered" and passed on from generation to generation, altering inherited traits. NOVA explores this new idea, interviewing top scientists in the field and following what could be a shift in the way we think about inheritance and our genes.

Kryptos - A strange sculpture resides on the CIA campus, in an area that only CIA agents are allowed to roam. Code-breakers have been obsessed with cracking the complex, alphanumeric code incorporated in the monument. The parts already decoded are mystifying: an allusion to the discovery of King Tut's tomb; a poem; and a reference to something buried on CIA grounds. It is said that only the director of the CIA and the artist himself know the meaning of Kryptos. Which code-breaker will be the first to share this knowledge?

T-Rex - Mary Schweitzer, who entered the field of paleontology as a middle-aged housewife, has questioned the science every step of the way. As a graduate student, she found what looked like red blood cells in a dinosaur bone, except that every paleontologist knew that was impossible and promptly attacked her work. Last March, Schweitzer announced the discovery of soft, spongy tissue from a 68-million-year-old Tyrannosaurus rex and shows that what science thinks is impossible sometimes turns out to be quite possible.

Arlie Petters profile - Arlie Petters, a native of Belize, holds a joint appointment in the math and physics departments at Duke University, where he studies optical lensing - using light as a metric to understand how gravity behaves in the universe. He developed the mathematical tools to research dark matter, black holes and the age of the universe, and will test a new five-dimensional "braneworld" theory of gravity that competes with Einstein's Theory of Relativity (which postulates four dimensions).