The Ascent of Man

The programme follows the changes in Man as he marches out of Africa, through desert and ice age, to leave the print of his hand in a dark Spanish cave.

The wandering nomads cease their migrations and settle in townships, learning new skills.

A man arrives claiming to know that Superboy is really Clark Kent. The man claims to be from Krypton. He offers Superboy an antidote to Kryptonite. The man is really an alien from another planet who wants to trick Superboy into losing his powers. Superboy does not fall for the deception because he is suspicious of the man due to a scar on his body.

A wealthy old man promises to give a large amount of money to anyone who can make him laugh. Clark Kent and Krypto attempt to make him laugh but fail miserably. Later, however, Clark must reveal himself as Superboy to the old man in order to save an airplane that is about to crash. The old man begins to laugh because he thinks that the idea that Clark Kent wants him to believe that he is Superboy is hilarious.

When Professor Ames feeds a chemical experiment to an elephant, it turns into a rampaging mastodon. Superboy and Krypto recapture the animal so that the professor can cure it. Unfortunately, one of the professor's assistants does the experiment again. Superboy and Krypto must head to Africa in order to get newingredients for another cure.

Dr Jacob Bronowski considers how the great achievement of physics in the 20th century has been to show that absolute certainty, in science or outside of it, is beyond our grasp.