In his first-ever appearance on C2C, Prof. Michio Kaku joined Art for the entire program to speculate on how new advances in physics could change the planet. Kaku first discussed the possibilities of solving the physics "holy grail" of combining equations describing the four fundamental forces of the universe.

He described four types of advanced civilizations from Zero (where we are now) to Type 1 (which would harness the natural power of the planet and control earthquakes), Type 2, which would use the power of the sun to run spaceships, and Type 3, which would "harness the power of the entire galaxy."

Kaku also discussed the "grandfather paradox" of time travel-- the theory that changing something in the past could change the future of the person who went back in time and killed their grandfather. He suggested that this act would simply create another universe where the person didn't exist. He warned about the Cassini probe that was due to be launched and powered by plutonium. If it crashed, it would cause "perhaps 200,000 people" to die from the radiation, he posited. In the last hour, Dr. Kaku took questions from listeners.