Trending Science: A stocking full of science

It’s not magic, it’s physics

One of the questions most dreaded by parents is when their child asks how Santa is able to deliver presents to all of the world’s children in just one night. Many resort to the ‘he does it with magic’ response but this wasn’t enough for one physicist, Dr Katy Sheen of Exeter University.

She hypothesises that Santa travels around the world at such speed that – according to Einstein’s theory of relativity - he shrinks, enabling Santa and his huge sack of presents to squeeze through even the tightest of chimneys and doorways. This also conveniently explains why restless and excited children rarely see Santa in the flesh.

Dr Sheen calculated that Santa would need to travel at about 6.2 million miles per hour to deliver presents to every child in 31 hours – taking into account world time zones. Such speed would make him change from red to green and eventually disappear entirely. In this case, it is the Doppler Effect which makes Santa change colour because the light waves bouncing off him are squashed at such a high speed.

However, Dr Sheen concedes that there is one aspect of Santa’s annual flight that science cannot easily explain. ‘... to fly this fast it takes lots and lots of energy. How does Santa manage to reach these phenomenal speeds? Well that’s magic. However, he would certainly need a lot of fuel.’

Where have all the reindeer gone?

Of course, Santa wouldn’t be able to take his annual flight without his nine trusty reindeer. This is why new research highlighting that the world’s largest wild reindeer herd has shrunk by 40 % has caused some concern.

Presented to the American Geophysical Union (AGU), the research highlights that reindeer in the Taimyr Peninsula in northernmost Russia are being affected by rising temperatures and human activity. The population reached a peak of 1 million in 2000, but this latest research suggests that there are now only 600 000 reindeer.

‘Climate change is at least one of the variables. We know in the last two decades that we have had an increase in temperatures of about 1.5 degrees overall. And that definitely impacts migration patterns,’ commented Professor Andrey Petrov of the Arctic Centre at the University of Northern Iowa.

Increasing industrialisation, wider - and thus more dangerous – rivers to cross and scarcer food sources in summer are all contributing factors to the population decline.

Prof Petrov argues that it’s now important to focus efforts on halting the decline. ‘Reindeer are tremendously important for biodiversity - they are part of the Arctic food chain and without them other species would be in trouble,’ he explained.

Computer says ‘Merry Christmas’

Finally, at the University of Toronto, a team of scientists have released the first Christmas carol composed through Artificial Intelligence (AI). They achieved this by feeding 100 hours of pop songs into a type of AI known as a ‘recurrent neural network’, which learns and performs by building connections between input data, much like the human brain.

The uploaded songs taught the neural network about the general structure of pop music. The researchers then tested its ability to generate a song about an image - a decorated Christmas tree surrounded by wrapped presents - using a process called ‘neural story singing.’

The researchers first had the computer produce a story about the Christmassy image. Then, they selected a rhythm of one beat per word, linked the endings of sentences to the endings of the music''s bars, and tuned it so that the vocals would occur in a ‘natural’ pitch range. The neural network then finalised the song by itself.

Other than a few questionable lyric choices, the network’s efforts did, in fact, produce something that resembles a Christmas song — there are references to Christmas trees, presents, and ‘lots and lots and lots of flowers.’ If interested, you can listen to the festive track here.

And on that happy note, everyone at CORDIS wishes you a very restful Christmas period, a Happy New Year and a successful and, of course, science-filled 2017!