since moved to the National University of Singapore.">

By Steve Pointing 16/12/2015


There is an increasing awareness that university science research needs to be relevant to the real world, so here I share a particularly good example of how science has helped to explain something I am sure we have all puzzled over at one time or another.

Father Christmas, or Santa as he is also known, does such an amazing job Christmas delivering gifts to children all over the world. It may, however, surprise you to know there are some who think what he does is impossible and because of this there are even people out there who don’t believe in Santa.

I have conducted theoretical research on this topic. Whilst the findings have not yet been published in a peer-reviewed journal, I think it clearly shows how science holds the answer to this particular issue and this will hopefully put any doubts to rest about Santa’s role at Christmas.

My research focused on 4 null hypotheses:

Ho 1: Santa cannot get around the world fast enough to deliver presents on Christmas Eve

This is a big task but it is certainly not impossible, and my research disproves this null hypothesis. There are approximately 2 billion children in the world and the average home supports 2.5 children. This means Santa has to get to around 800 million homes on Christmas Eve.

There are a few elements of physics in his favour. For example, the Earth is rotating at around 1,600km/hr and this creates a 24 hour day, but by flying ahead of the sunrise as the Earth rotates Santa can actually get almost two nights to deliver presents.

Even with this extra time, he still needs to move pretty fast and so the most likely explanation is that he uses an antimatter rocket to give his sleigh near light speed capability. Antimatter has the same mass as normal matter but the opposite charge, so when matter meets antimatter the annihilation of both occurs and a vast amount of energy is released – for example 1kg antimatter would release the same energy as 43 megatons of TNT.

Particle accelerators and some types of radioactive decay produce antimatter particles, but antimatter atoms are quite difficult to produce – so far only anti-hydrogen and anti-helium has been made. NASA is studying antimatter as a potential interstellar propulsion system because it can potentially achieve near-light speed travel, but Santa has obviously beaten them to it!

Ho 2: Santa is not real because nobody sees him delivering presents

Science clearly disproves this null hypothesis, although there is some confusion among explanations.

Santa is of course real, and some have speculated that he has evolved some kind of biological camouflage pigments to blend in with his surroundings, much like chameleons, cuttlefish and other animals.  It is doubtful in my view that this kind of evolutionary adaptation would occur in a mammal, and so instead it seems quite obvious that he is using a technological solution.

A team of researchers at Rochester University (USA) developed lenses that literally bend and reflect light to create the illusion of invisibility. They worked by focusing light off-centre through the lens, and continuously refocusing light through layers of lenses. These could be applied to any material to render it invisible. This low-tech solution is clearly something that could be achieved using standard tools in Santa’s workshop.

Ho 3: Santa is too big to fit down the chimney

Again this null hypothesis is easily disproved using science, but this time using biology.

There are plenty of animals that have remarkably flexible bodies – think of an octopus, although they are invertebrates. However, even some vertebrates are super flexible and have joints that articulate way more than ours, for example, weasels are extremely ‘bendy’ creatures. For these animals, the only restriction to getting down a narrow hole is the skull as this cannot be compressed.

So if Santa were to do plenty of Yoga and Pilates during the long ‘off season’ between Christmas Eves he is probably flexible enough that a chimney only needs to be a little wider than his head. The average human male head is 17cm wide, and standard chimney diameter according to building codes is 36×15 inches (90×37.5cm) for older houses (UK building codes dating back to the last century) and in modern Kiwi houses a chimney is usually 30cm wide. So clearly there is plenty of room for Santa provided he sucks in his belly on the way down!

Ho 4: Rudolph is a reindeer and they do not have noses that glow

Biology once more provides the answer and disproves the null hypothesis. This is due to two phenomena, bioluminescence and horizontal gene transfer.

There are loads of animals and plants out there in nature that glow in the dark – just think of fireflies and glowworms. They glow because of something called bioluminescence (something Kiwis know lots about thanks to the amazing work of Dr Siouxsie Wiles at Auckland University).

Bioluminescence is basically light that is produced in a living creature by a chemical reaction, interestingly it is a ‘cold’ light – only around 20% energy lost as heat!  It occurs when a chemical called luciferin interacts with a protein, either an enzyme called luciferase or a photoprotein. This is either present in the animal or can be due to a symbiosis with bacteria that do this, as for example in some shrimp and squid.

There are several Arctic mosses that are bioluminescent, and, of course, this is where Santa’s reindeer live, and moss happens to be a favourite food for reindeer. It has also been revealed in the last 15 years or so that several species of microbe and primitive plants can exchange genetic information across the species boundary in what is known as ‘horizontal gene transfer’ – for example this is how bacteria acquire antibiotic resistance.

It seems that what has happened in Rudolph’s case is that the moss genes encoding bioluminescence pigments and proteins have been transferred to the reindeer in a horizontal gene transfer event. Of course there is another problem, moss bioluminescence is blue-green but we all know Rudolph’s nose glows red – but this too is easy to explain – the orientation of luciferin molecules can influence the colour of bioluminescence, and also think about when you shine a torch behind your fingers, the blood makes the light appear red.

Obviously you will probably be reading about these findings in Nature or Science soon, but in the meantime if you want to see a video that explains the theories in greater detail here it is: The Science of Christmas.

Featured image: Flickr CC, DAVID MELCHOR DIAZ.