The science of Christmas

Roger Highfield

Roger Highfield on the real-world evidence for holy turkeys, Rudolph’s red nose and Santa’s warp drive

19 December 2018 09:28

Two decades after I wrote the first book on the science of Christmas, I am happy to report that researchers are still pushing back the frontiers of festive knowledge.

Diligent scientific research can unwrap new insights into our seasonal rituals, and one of the more surprising recent revelations is that, if we were true traditionalists, we would worship the turkey on Christmas Day, not eat it.

This reverential picture of the bird emerges from a study of 55 turkeys which lived between 300 BC and 1500 AD in Mesoamerica. A team from the University of York, the Institute of Anthropology and History in Mexico, Washington State University and Simon Fraser University was able to use DNA to confirm that today’s turkeys are descended from a Mexican wild ancestor, known as the huaxolotl (‘clown of the jungle’), which was the first animal, other than the dog, to be domesticated, eventually arriving in Britain in the 16th Century as part of its spread across Europe via Spain.

The team also measured carbon isotope ratios in the turkey bones to reconstruct their diets, showing they were gobbling corn and other crops in ever-increasing amounts down the generations. But they found that the rise of turkey farming did not correlate with an increase in human population size, a link you would expect to see if turkeys were reared simply as food.

Lead author at the University of York, Dr Aurélie Manin, pointed out that many of the turkeys they studied had not been eaten. Some had been buried in temples, and, in Eastern Mesoamerica on the Gulf of Mexico, she said that there are several examples of turkeys offered in graves to accompany the deceased to Mixtlan, the Mesoamerican afterlife. ‘This fits with what we know about the iconography of the period, where we see turkeys depicted as gods.’

Sun worship is a unifying feature of the seasonal celebrations. Visit the Sun exhibition in the Science Museum, and you can see how ancient cultures had an intimate relationship with our local star, using it to organise their days, understand the seasons, and often worshipping it as a deity of fire, life and rebirth.

Dr Harry Cliff, lead curator, points to 3,000-year-old artefacts in the exhibition that show how people in Bronze-Age Denmark thought that the Sun was carried through the sky by a chariot. One can only assume that, long ago, when the sun ebbed away as the winter solstice approached, there was a real fear that the chariot had broken down and action was needed to get the Sun back on track. This is why candles, yule logs and other trappings of what we now call Christmas are so important at this time of year.

To a shivering pagan in a deciduous world, an evergreen such as a fir suggested permanence and a magical ability to thrive without much help from the sun. The same goes for plants with winter berries, such as holly or mistletoe.

The good news is that, whatever seasonal rituals our ancestors concocted to ensure that the sun reappeared, whether burning candles or using decorative evergreens, they always succeeded in persuading warmth and life to return.

The urge to celebrate the festivities is so strong that, 50 years ago, when the first humans went into orbit around another world, they celebrated the first Christmas in space. Millions listened and watched as the Apollo 8 astronauts – Frank Borman, Jim Lovell and Bill Anders – read verses from the book of Genesis, inspected the dark side of the moon, and took the iconic ‘Earthrise’ image to give humankind a new perspective on their home planet.

On Christmas morning, mission control waited anxiously for word that Apollo 8 had successfully fired its engine to depart lunar orbit. Confirmation of the critical burn came when Lovell radioed, ‘Roger, please be informed there is a Santa Claus.’ There is indeed. With Thomas Oléron Evans Hannah Fry of University College London opens her book The Indisputable Existence of Santa Claus with not one but three mathematical proofs of his existence.

In my book, I speculated that in the North Pole, or perhaps the island of Gemiler off Turkey (home of St Nicholas), there must be an army of elves experimenting with the latest technologies, all united by a single purpose: delivering presents to delight millions of children.

Traditionalists like to claim that Rudolph’s nose provides an important hint of friction heating, consistent with high-speed present delivery, leading Prof Matthew Freeman of the Dunn School, University of Oxford, to speculate that Santa manipulated genes to enable reindeer to sprout stabilisers, even wings.

However, last year in the journal GigaScience, Dr Zhipeng Li of the Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, and colleagues described the analysis of the reindeer genome, consisting of 2.6 billion ‘letters’ of DNA, based on blood from a reindeer kept by Ewenki hunter-herders from Inner Mongolia.

Although their DNA recipe is a superb resource for gaining greater understanding how reindeer, cattle and goats separated from a common ancestor around 30 million years ago; when it comes to why Santa’s reindeer can fly, ‘we haven’t the answer,’ admitted Dr Li.

Santa’s elves may have devised a way to warp space-time.

Physicists have other ideas. Santa’s elves may have devised a way to warp space-time, allowing the sleigh to sit in a bubble of space that itself moves, so that it could travel faster than light (it’s really not so far-fetched – there is the Alcubierre warp drive, named after Miguel Alcubierre).

Or Santa may, with the help of exotic materials, create space-time shortcuts called ‘wormholes’, as conceived by Kip Thorne of Caltech, who shared the Nobel prize last year for observing ripples in spacetime, called gravitational waves. Wormholes not only allow Santa to shift from chimney to chimney, but to make temporal hops too, providing all the time in the world to deliver presents. Others have also suggested Santa resorts to quantum teleportation, akin to Star Trek, though it is trickier to do than many realise.

Whichever advanced technology you think he uses, there is one irrefutable fact: the night before Christmas, Santa will deliver those presents as reliably as Rudolph’s nose is red.

Roger Highfield is a director of the Science Museum, and author of Can Reindeer Fly? The Science of Christmas.