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Absolute Zero

Absolute Zero
A Two-Hour Special
TV Program Description

Original PBS Broadcast Dates: January 8 & 15, 2008

Air-conditioning, refrigeration, and superconductivity are just some of the ways technology has put cold to use. But what is cold, how do you achieve it, and how cold can it get? NOVA explores these and other facets of the frigid in two one-hour programs.

The two-part special follows the quest for cold from the unlikely father of air-conditioning, the court magician of King James I of England in the 17th century, to today's scientists pioneering superfast computing in the quantum chill near absolute zero—the ultimate extreme of cold at minus 273.15 C (minus 460 F). (See A Sense of Scale to put this temperature in perspective.)

Along the way, viewers learn about the invention of thermometers, the origin of the ice business in 19th-century New England, Clarence Birdseye's fishing trip that led to the invention of frozen food, and a couple of cold-inspired scientific races towards absolute zero that ended in Nobel Prizes.

NOVA brings the history of this frosty subject to life with historical recreations of great moments in low-temperature research and interviews with noted historians and scientists, including Simon Schaffer of the University of Cambridge, and Nobel laureates Eric Cornell and Carl Wieman of the University of Colorado at Boulder and Wolfgang Ketterle of the Massachusetts Institute of Technology.

The program is based on the definitive book on cold: Absolute Zero and the Conquest of Cold by Tom Shachtman. (See an excerpt.)

Part One, "The Conquest of Cold," opens in the 1600s when the nature of cold and even heat were a complete mystery. Are they different phenomena or aspects of some unified feature of nature? Are they added to a substance or qualities of the substance itself? The experiments that settled these questions helped stoke the Industrial Revolution, which exploited such fundamental insights as that heat always flows from hot to cold. (Learn about the mysterious opposite to absolute zero.)

The key moments in cold in this episode include: Cornelius Drebbel's spooky trick of turning summer into winter for the English king, achieved in much the way that homemade ice cream is produced; Antoine Lavoisier's battle with Count Benjamin Rumford over the caloric theory of heat, an intellectual contest set against the backdrop of the French Revolution, in which Lavoisier unfortunately lost his head; and Michael Faraday's explosive experiments to liquefy gases, which established the principles that make refrigerators possible. (For more, see Milestones in Cold Research and Anatomy of a Refrigerator.)

Part Two, "The Race For Absolute Zero," picks up the story in the late 19th century, when researchers plunged cold science to new lows as they succeeded in reaching the forbidding realm at which oxygen and then nitrogen liquefy. (See if you can liquefy oxygen yourself.) The master of this technology was Scottish chemist James Dewar, who pursued the holy grail of the field—liquefying hydrogen at minus 253 C, just 20 degrees above absolute zero. When he succeeded, he faced the unexpected and even more daunting challenge of liquefying the newly discovered gas helium at a mere 5 degrees above absolute zero. However, he had a talented competitor—Dutch physicist Heike Onnes—and the ensuing race to the bottom of the temperature scale was as zealous as the contemporaneous race to the Earth's poles.

The end of the 20th century produced another low-temperature contest. No one had ever seen an exotic form of matter called a Bose-Einstein condensate, which only forms at temperatures vanishingly close to absolute zero. But new techniques developed in the 1990s by Daniel Kleppner at the Massachusetts Institute of Technology set the stage for a race to create this truly bizarre substance—and with it win the latest heat in the quest for cold.


Program Transcript
Program Credits

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Recreation of Dewar's liquefying of hydrogen

One of the key steps in approaching absolute zero—the rock-bottom possible temperature at minus 460 F—was liquefying hydrogen, which Scotsman James Dewar succeeding in doing in 1898. Here, a recreation of that accomplishment from NOVA's program.

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