Neil deGrasse Tyson discusses the move from classical physics to modern physics. He then examines the Pioneer Anomaly and how the Pioneer space probe is slowing faster than predicted. He discusses dark matter and how it accounts for the gravity of the universe even though we know next to nothing about it. He then examines dark energy which is the unknown force causing the expansion of the universe to accelerate. He also considers some anomalies facing quantum mechanics and the theory of the Zero-energy universe. Finally, he examines the likely collision between the Milky Way and the Andromeda galaxy.
