Renowned astrophysicist Neil deGrasse Tyson hosts this fourth installment of the fast-paced and provocative science newsmagazine, now in its second season on PBS. This episode includes:

Emergence - In any large group of individuals, there is a leader with a plan, right? Well, not always. Scientists are finding that order doesn't necessarily spring from the top down. Complex group behaviors emerge spontaneously: thousands of starlings flock as one, schools of fish evade predators in what seems like a highly choreographed dance, neurons in our brains fire in rapid, coordinated succession. This phenomenon, called "emergence," is transforming math, biology, cognitive science and the way we perceive the world.

CERN LHC - It could be the boldest experiment in all of science, one that could answer a profound question: What is the universe made of? CERN, the particle physics lab in Switzerland, is constructing a new particle accelerator, the Large Hadron Collider (LHC). With a 17-mile circumference, the structure is essentially a giant circular magnet with protons zipping around inside of it. Scientists are trying to detect the elusive Higgs, also known as the "God particle" for its essential role in particle physics, which supposedly accounts for the mass of all other particles - if only researchers could find it. With luck, the LHC will do just that and in the process answer unsettled questions about the nature of matter.

Tuesday, 7/10/07 from 8-9 p.m. and 1:30-2:30 a.m. ET
Friday, 7/13/07 from 4:30-5:30 a.m. ET