On Science: The Santa hypothesis
This article first appeared in the St. Louis Beacon, Dec. 24, 2008 - Yesterday my daughter Caitlin arrived home from college for the Christmas holidays. She has learned there that she knows much more than her parents, but seems to be doing her best to hide this guilty knowledge from us. Looking at her now, a confident young woman, I cannot help but think -- as many fathers must -- of earlier Christmases. Years ago, I wrote of Christmas and Caitlin, and I can think of no better way to celebrate Christmas this year than to rerun that column for you today, the day before Caitlin and I celebrate this year's Christmas. So, here it is:
Tonight is Christmas eve, and my daughter Caitlin and I are going to sort out this Santa Claus business once and for all. There was a time, only a few very brief years ago, when all three of my daughters believed in Santa Claus. But, much as I have resisted the process, my daughters have grown older. Christmas has become a less magical if no less loving time, a celebration of family, rich with presents and cheer and hope.
Except for my stubborn one, my Caitlin. She who believes in fairies and everyday magic finds it hard to relinquish Santa, her faithful childhood friend. She does not want to give up her childhood, or Santa. She came to me this year and said, "Look, dad, is this true? Is there a Santa?" What is a father to say to a child he loves about letting go of childhood?
What I said was "Look, I'm supposed to be a scientist. Let's test the hypothesis."
With grave delight, Caitlin set about helping me formulate a set of testable hypotheses. First, as in most science, comes the library work. It turns out that while St. Nick is an old Christmas tale, people have known about Santa for only 200 years. The general public first became aware of him in a book called Knickerbocker's History of New York, written by Washington Irving in 1809. In it Irving describes a rotund fellow in a red coat riding over treetops in a wagon drawn by reindeer bringing gifts to children on Christmas eve. The Dutch word for St. Nicholas is "SinterKlaas," and in Irving's book the name is pronounced the way a child would, as "Santa Claus." The details were fleshed out 14 years later, when in 1823 Clement Moore wrote "Twas the night before Christmas..."
This then is the data set Caitlin and I had to work with. The core of the theory of Santa Claus is that there is this overweight guy who flies a reindeer-drawn sleigh to every house on Christmas eve, giving presents to children.
So, what's so hard to believe about that? Caitlin and I discussed this at length, and settled on two testable hypotheses. Accepting either one of them stretches the credibility of even a child who believes in fairies. If they both prove true, then surely Santa must be.
1. Reindeer really know how to fly. The idea of Rudolph and Prancer and all those other reindeer flying through the air runs contrary to any deer we ever saw. Without wings or a rocket-like digestive system, it's hard to see how a reindeer could fly.
2. Santa can get down the chimney. How does a really fat old man slide down narrow chimneys? How does he squeeze through, and why doesn't he get seriously dirty? And what about houses that don't have a fireplace?
The essence of science, as I have often rather pompously explained to my daughters, is testing. To test these two hypotheses, Caitlin and I devised two experiments, to be carried out tonight, on Christmas eve.
Experiment One: A Flying Reindeer Detector.
If reindeer really fly, drawing Santa's sleigh to our roof, then they would have to pass between two sets of great trees that loom over our house, one at each end. There simply isn't any other way to approach our roof through the air except through the opening between these trees. So up the ladder I went one morning this week, Caitlin gallantly trying to hold the ladder steady. At one end of the house I tie a black thread to a tree limb. Then I toss the spool as hard as I can over the rooftop toward the far side. With a lot of fussing, I manage to fish the thread over; and climbing the ladder at the other end, I draw the thread tight and tie it to a tree branch. On the thread we have hung several tiny bells, designed as decorations but up to the task at hand. Any reindeer that flies over this roof is going to ring our little bells. My tape recorder, turned on at midnight, will serve as our detector.
Experiment Two: A Santa Trap
Our house has several chimneys. To channel Santa's entry to the living room, Caitlin and I have closed the flue in the other chimneys, and crammed a chair into each fireplace so the flu can't be forced open from the outside. In the living room, we set our Santa trap. The living room has a big rug extending all the way from the fireplace to the far corner, where the Christmas tree is. As a preliminary test, we took the living room rug up, and poured over the floor two large boxes of crinkly packing material. You know the kind - sheets of plastic bubbles that go "pop" when you press them. Then we rolled the rug back. As the final touch, we put Caitlin's tape recorder on the mantle over the fireplace, nestled inconspicuously among the ornaments. The idea was that we would turn it on before going to bed, so that if Santa comes down that chimney and goes to that tree, we would be able to hear the "pop, pop" of his passage.
Ever my daughter, Caitlin decided on a test of the Santa trap, turning on the tape recorder and then walking seriously over to the Christmas tree. Did our trap work? Was her passing recorder on the tape? Nope. Not a sound, "pop" or otherwise, was recorded on the tape - not even daddy walking over the rug to turn the tape recorder off.
Failure did not deter us. The problem with our Santa trap was clearly due to poor experimental design. What we needed, Caitlin decided, was a way to track Santa, like following tracks in snow. It did not deter Caitlin that because our living room floor is not covered in snow, Santa would not be expected to leave tracks as he moves from fireplace to Christmas tree. She points out to me that there is nothing wrong with the logic of looking for tracks -- all we have to do is provide "snow." So we have set up a new Santa detector, one we have not yet cleared with my wife. Late on Christmas eve, at bedtime, we are going to blow a fine cloud of flour across the front of the fireplace. Santa's steps should be recorded on the floor. I am assured by my daughter that it will be no problem to vacuum the flour up later.
The daddy control
Any experiment is only as good as its controls. A control is something you do to eliminate the possibility that a positive result might be created by something other than the factor you are testing. It has occurred to my daughter that Santa is not the only animal that can walk across living rooms. Her control for our experiments designed to detect Santa Claus is to stay up all night with her father on Christmas eve, with a cord tied from her wrist to mine. I cannot imagine why.
So there you have it. Our experiments have taken days to set up, a vivid time full of laughter and discussion of Santa. A key question occurs to me: If our ideas about Santa originated with Washington Irving in 1809, how did Irving learn what Santa was like? There is no hint of this Santa before him. I ask Caitlin, who answers logically: "Washington Irving must have SEEN Santa himself."
And suddenly it occurs to me. "Of course he did - in his whimsical mind's eye!" The real essence of the theory of Santa Claus is not flying reindeer or sliding down fireplaces, I realize, but belief in them. Santa Claus is belief in wonder, readily accepting the possibility that what we don't know may be true. One fertile accepting mind like Irvine's can create an idea that outlasts time.
As Caitlin and I busily finish our preparations to scientifically test the theory of Santa Claus, I realize that carrying out the investigation has been, in itself, the real proof I was seeking. The surmise that Santa might be, so readily accepted by my daughter, proves that the Christmas sense of wonder survives in her - and, I hope, in me.
George B. Johnson's "On Science" column looks at scientific issues and explains them in an accessible manner. There is no dumbing down in Johnson's writing; rather he uses analogy and precise terms to open the world of science to others.
Johnson, Ph.D., professor emeritus of Biology at Washington University, has taught biology and genetics to undergraduates for more than 30 years. Also professor of genetics at Washington University’s School of Medicine, Johnson is a student of population genetics and evolution, renowned for his pioneering studies of genetic variability.
He has authored more than 50 scientific publications and seven texts, including "BIOLOGY" (with botanist Peter Raven), "THE LIVING WORLD" and a widely used high school biology textbook, "HOLT BIOLOGY."
As the founding director of The Living World, the education center at the St Louis Zoo, from 1987 to 1990, he was responsible for developing innovative high-tech exhibits and new educational programs.