With no natural light, submarines re-invent the workday. Frustrated with hundreds of local time zones, a railroad clerk fights to standardize time. Navigation, travel, and technology advances result from unrecognized contributions to time.

The invention of the mirror gives rise to the Renaissamce; glass lenses reveal worlds within worlds worlds; glass is essential; for communication in the deep ocean; glass lens allows millions to watch a man walk on the moon.

The pioneers of light; Edison's light bulb; a French scientist accidentally discovers a neon light.

Ice delivery becomes big business, the father of frozen foods, Clarence Birdseye, and his vision for the future, and penguins who live in the desert.

30,000 year old traces of a desire to record sound are located in caves, how radio influenced the civil rights movement, the weapon that laid the ground work for today's mobile phones, and the role of the ultrasound in modern medicine.