Brainy Rudolph

Tis the season to be jolly – for many a time to wind down from the year’s pressures, a time to relax as a new year waits in the wings. But just before you reach for the sherry – Science lite has a rather terrifying task for you to consider.  

If I told you that you had to deliver 321,000 tonnes of cargo to 91.8 million homes I imagine you might feel a little daunted. If you were then told that there was a vital time pressure to this task ­– just 36 hours in fact – then I would fully expect you would break out in a sweat.

However this is the feat a certain Mr S. Claus will face in less than a month’s time. Yet we suspect he is currently sitting with his feet-up, not a bead of perspiration to be seen on his distinctly unfurrowed brow.

This air of calm pervades because Santa knows it is not he that will shoulder the weight of this task. A figure head for the operation – a mere showman intent on forwarding the brand, he does not trouble himself with physical exertion. No, the real workers are, of course, his trusty reindeer. It is they that have to do battle with the laws of physics as they attempt to slip the shackles of gravity and haul Claus and his cargo to sky. It is they that need then to propel their consignment to 650 miles a second to get the job done on time. It really is not the season to be jolly if you are a reindeer assigned to the Colonel Claus squadron of yuletide logistics. T’is rather the season to be over worked.

It stands to reason that all this physical exertion must make for a very toasty Ruldolph. So if the 12 real heroes of Christmas have to work so hard for the sake of the season – how do they stay cool?

It might not seem like the most obvious of questions to ask of a mission that stretches and warps the laws of science in pretty much every aspect of its execution – but it is a question that may well have an answer. And a team of biologists from Norway – where else? – think they may have found it.

After spending many hours examining a reindeer on a treadmill – yes you did read that correctly, a treadmill – the team think that the real trick of the reindeer isn’t their annual ability to fly, but how they keep cool. After light exercise they utilise their noses – black ordinarily, famously red in the case of Rudolph – allowing air to evaporate water from the mucous membranes cooling the blood and sending it back to the rest of the body. When things pick-up a bit they move to phase two of the cooling strategy and flop out their tongues to perform a similar task.

But it is the third prong of the attack on metabolically driven heat that really sets apart the reindeer. Once their temperature reaches a balmy 39°C the reindeer can selectively cool the brain by diverting cool venous blood – coming from the nose – away from the body and up into the head. Here it is passed over a series of heat exchanging blood vessels cooling the hot arterial blood destined for the brain.

And so for all those mindful of the real heroes of Xmas – rest easy, evolution has armed them well for the task in hand.

• Christmas Quiz

  Just e-mail the answer to our festive query to phil.prime@laboratorynews.co.uk and you could win a rather fantastic bundle of popular science books – including Professor Brian Cox’s latest The Quantum Universe and Johnny Ball’s Ball of Confusionplus many more.

  To win you need to don your smartest thinking cap and tell us what you think is the most amazing feat Santa performs as he delivers his gifts. Many a scientific law is bent, broken and smashed as he goes on his travels – what do you think is the most amazing?

  E-mail phil.prime@laboratorynews.co.uk with your ideas by Friday 23^rd December – best explanation will win.