Season 31

1.Infinite Secrets

2.Who Killed the Red Baron?

3.The Elegant Universe: Einstein's Dream (1)

4.The Elegant Universe: String's the Thing (2)

5.The Elegant Universe: Welcome to the 11th Dimension (3)

6.Wright Brothers' Flying Machine

7.Magnetic Storm

8.Volcano Above the Clouds

9.MARS Dead or Alive

10.Secrets of the Crocodile Caves

11.Dogs and More Dogs

12.Descent Into the Ice

13.Crash of Flight 111

14.Life and Death in the War Zone

15.Hunt for the Supertwister

16.World in the Balance: The People Paradox (1)

17.World in the Balance: China Revs Up (2)

18.Battle Plan Under Fire