Alan Yentob explores the work of artists whose primary medium is light. On his trip down the light fantastic, Alan encounters material from outer space, solid light sculptures, paintings made by the sun and an extinct volcano that has been turned into a temple of perception by the legendary American artist James Turrell.

Sculptor and giant of modern art Richard Serra discusses his extraordinary life and work.

A creator of enormous, immediately identifiable steel sculptures that both terrify and mesmerise, Serra believes that each viewer creates the sculpture for themselves by being within it.

To this end, a Japanese family are reminded of the Temples of Kyoto, a Londoner finds sanctuary in the Serra near Liverpool Street station, and most movingly, a Holocaust survivor sees one piece as a wall separating the living from the dead.

Contributors include Chuck Close, Philip Glass and Glenn D Lowry, Director of MoMA.