Our Thermal Safety

Dear Thermodynamic Ones:

In 1892, Scottish chemist James Dewar (no relation to John Dewar of the Scotch distillery) invented the thermal flask. His goal was to measure the specific heat of the element palladium. Dewar needed to stabilize the sample’s temperature before heating it in order to generate consistent data for his calculations. To solve this problem, he formed two brass containers and nested one inside the other. By heating and sealing the space between them, Dewar created a vacuum between the walls of the two flasks. Heat is transferred through the friction of molecules in motion as they crash into each other; the kinetic energy of their movement is absorbed and given off as radiated heat. If you reduce the number of molecules in a container, it’s harder to transfer heat because there are fewer bumping into each other. (This is why your down coat keeps you warm—the feathers have lots of space between them, and the trapped air has fewer molecules banging around to radiate your body heat to the outside. A solid piece of cloth is denser, so it transfers the heat quicker—but I digress.)

While few people remember the specific heat of palladium (0.24 Joules per gram per increased degree Centigrade), we are all familiar with his thermal flask. In fact, you may be sipping hot coffee from one right now. Really, I’m going somewhere with this.

I’ve been musing about keeping people warm on cold winter days. The secret is finding places where the air is heated and contained, not mixing with the cold winds outside. This can be done with coats and shelter; our bodies also need nutritious food to generate heat and fuel for furnaces or heaters. I’m confident if any one of you saw someone poorly dressed for the weather and freezing on your front lawn, you would go to your closet and grab a sweater, a cap, or coat and gloves—the ones you seldom wear—and give them freely to the poor shivering soul. You may even offer them a thermos of warm soup. Let’s face it, we have more thermal cups and mugs than we need.

The problem with such easy generosity is that we now live in social vacuum bottles. There is little warming mass between our insulated communities and those left out in the cold. This is by design; the chance that you will have a shivering soul on your steps is quite small. Thanks to zoning laws and local ordinances, we have designed our systems and cities to give vast empty space between our warmth and those left in the cold. Carefully curated corridors of vacuum-sealed transportation render Jesus’ parable of the Good Samaritan strangely quaint. I may see someone broken down on the road, but if I discern that they have a cell phone, I’m comfortable in assuming their ‘electronic straw’ will extending out of their mobile thermos to connect to equally insulated authorities who should arrive long before they freeze to death. Taxes paid; problem solved.

Except, we are now living in an age where the vacuum between us warm ones and those cold ones is getting larger; the bouncing molecules of human conductivity are decreasing. (I’ll allow you to connect your own dots between current policies and orders targeted at keeping us better insulated.) Some, even in the name of religion, claim that increasing our heat transfer distance is a virtue. I have now heard some teach that Jesus wants us to warm only those who are physically and socially closest to us. This is good, they claim; we are supposed to keep the cold ones further away. 

Clearly, they believe the Good Samaritan’s big mistake was not choosing a safer road. Think of how his own family could have used the resources he wasted on a guy who may have deserved the beating he received. Charity, after all, begins at home, and if all our charitable energy is expended there, we are protected from the risk of doing moral damage outside our insulated carafes.

Of course, some hearts can’t help but bleed; so, agencies, programs and other assorted do-gooders occasionally slip through the airlock and transfer assistance. But because we cannot oversee their work, they come under suspicion. We’ve outsourced our generosity, so we are prevented from witnessing any transformation. We become cynical about their efforts and turn to our heat giving energy homeward. Specific heat is a function of density—the densest ones swap the most warmth among themselves.

Another wonderful thing about vacuums is that not only heat but also sound travels poorly through them. If the vacuum is tight enough and vast enough, not only will you not lose heat, you’ll also never have to hear them scream.

Hoping to puncture the vacuum rather than pour the Dewars, I remain,

With Love,
Jonathan Krogh
Your Pastor