The Invention of Cold

We are energy guzzlers. As humans. As creative technological beings. As comfort-seeking creatures who change the environment around them.

 

Consider a bacterium. It makes just enough energy for itself to survive, and possibly procreate. But at some point in Earth’s history, one ate another (technically archaea eating bacteria), and more complex unicellular creatures (eukaryotes) appeared on the scene with superior energy transducing abilities – thanks to new little engines we now call mitochondria. Cells signaled each other, and started to cluster in colonies, sharing out the work, specializing and becoming more efficient. And thanks to the buildup of free molecular oxygen, they could become bigger multicellular organisms – gorging more energy and burning it up as they built brain and brawn.

 

While every other living creature eats to live, human beings wanted more. We wanted more food. We wanted it to look bigger and better. We wanted more shelter. Bigger and better. We wanted stuff to make our life easier – machines to do the labor. We wanted to live wherever we chose (from the desert to the mountains), travel with ease and speed, communicate in new ways, and tickle our fancies with novel entertainment. New creations require energy when raw matter is shaped into technology. We dug deep to find new energy in black gold, harnessed the power of wind and water, imitated green plants as they looked to the sun, and unlocked the secrets hidden in the tiny nucleus of the atom.

 

Adding energy adds heat, increasing the wiggle and dance of atoms and molecules. We humans know how to add Heat, and we’ve been doing this for a long time. Using Fire in its myriad forms, we burn, burn, burn. But the laws of thermodynamics are relentless. Heat, a most inefficient form of energy, dissipates until the temperature of the hearth matches the temperature of its surroundings. More fuel is needed for the fire to maintain heat. Hot things cool down. We notice this easily because the object of our attention is small and specific. But it is surrounded by the large thermal reservoir of our environment, hardly changes its temperature as it absorbs our heat and not our attention. You might say that the cold does get hot, but we never notice if we can’t tell the difference.

 

This makes the invention of Cold all the more interesting. It’s a fascinating tale, spun by a master story-teller, Steven Johnson, in his book How We Got to Now: Six Innovations That Made the Modern World. 

 

The story begins with a Bostonian, one Frederic Tudor, who hatched a plan to ship large blocks of ice from the cold Northeast to the sunny Caribbean. The ice survived the trip, but Tudor hadn’t taken marketing into account – the locals didn’t think it useful, not having needed this seeming “luxury” for as long as they could remember. And the ice does eventually melt down in the heat of the tropics. Surviving debtor’s prison and persevering with his “ice trade”, Tudor’s luck eventually turned. In the sweltering heat, when there are those who can afford the luxury of cooling down, there’s profit to be made. And it wasn’t just the Caribbean.

 

We all need to eat. Our bodies need fuel to burn. Refrigeration would completely change the food industry, from the Chicago meatpackers of the nineteenth century to the flash-frozen food innovations of Clarence Birdseye. How do you feed an urbanizing population with ever-more complex lifestyles? Can we live and work more comfortably in our dense concrete jungle? Can we enjoy a theater performance indoors in the summer? Can we cool the air in a hospital ward for patients suffering from fever and ague?

 

It is this last question that eventually gave us modern air-conditioning. John Gorrie, a doctor in Florida, “suspended blocks of ice from the hospital ceiling” to help reduce the fever of his patients and make them more comfortable. But ice shipments were sometimes delayed, and the good doctor built his prototype using recently discovered scientific knowledge of how gases behave. If you can compress a gas, then cool it down to room temperature (for example with running water), and then allow it to expand, the gas will “pull heat from its environment”. This is still the strategy used in air-conditioners and refrigerators today. We’ve become clever and efficient at doing this, and can boast of huge buildings in an ever-increasing metropolis. Always comfortable on the inside, no matter what the temperature is outside.

 

Tudor’s story begins barely two hundred years ago; Birdseye’s flash-frozen food, just a hundred years ago. They seem like old stories, but they’re relatively new in human history. The invention of Cold looks easy. But when your refrigerator or air-conditioning unit breaks down, you’ll likely throw up your hands in despair and quickly call an expert for repair. It takes energy to fight thermodynamics and keep things colder than the ambient temperature. No organism does it well. Pulling energy out of a system to cool it down is a very neat trick that creative humans with the knowledge of science and technology can now perform. Until recent history, the idea that a box could cool things down would have seemed like magic. (I suppose you could try trapping a Dementor.) Humans can be wizards in their own way.