IOP unwraps its ‘Seven Wonders of Christmas’

As the nation prepares for the Christmas holidays, the Institute of Physics (IOP) has released details of seven Christmas ‘wonders’ which it says we can all try to spot however or wherever we spend the season.

The IOP’s experts, assisted by writers from Physics World and Shyam Balaji, researcher in astroparticle physics and cosmology at King’s College London, have produced this year’s seven wonders, which make the case that even at Christmas, physics is all around you.

Seven phenomena or fascinating facts have been identified by the team, which can either be viewed over Christmas or used to amaze and astound friends and relatives at Christmas celebrations.

The things to spot include the Ursid meteor shower peaking on 22 December, the unique way wine flows up the side of your glass and the magical meta-material qualities of a Christmas jumper.

And among the mind-expanding science on display are the first models of the atom, which for a while was thought to be a little bit like a Christmas pudding, and the time-bending qualities of Santa’s sleigh.

Tom Grinyer, chief executive of the IOP, said: “I hope everyone enjoys reading about our ‘Seven Wonders of Christmas’, they are a reminder that at Christmas, like every other time of the year, physics is all around you.

“It’s a bit of festive fun from the team here but if it inspires some people to take a bit more interest in physics and the way its phenomena and processes underpin so much of our everyday life then it will have been worth the time we spent on it.

“Everyone who is out watching shooting stars at night, enjoying a glass of wine with Christmas dinner, wearing a Christmas jumper or just wondering why the days are so short is experiencing some of the wonder of physics, as well as the joys of Christmas – so to all of you, and everyone else, a merry Christmas and a happy New Year from everyone at the IOP.”

The IOP will be posting daily details about each one of its ‘Marvels’ on its social feeds during the Christmas holidays.

The IOP’s Seven Physics Wonders of Christmas

1. Shooting Stars

The Ursids meteor shower will be peaking on 22 December as debris from Comet 8P/Tuttle enters our atmosphere and burns up. Unfortunately for festive star gazers it’s generally quite a sparse shower, producing about 5-10 meteors per hour under ideal conditions. At least there is some hope of spotting any shooting stars this Christmastime – the quarter moon will only appear above the horizon at midnight, so the sky should be dark until then.

2. Your Christmas pudding is a bit, but not entirely, like an atom

One of the earliest proposed models for the atom was suggested by JJ Thomson in 1904, after he had discovered the electron in 1897. He theorised that atoms were a bit like a plum pudding, with a positive ‘dough’ with a lot of negative electrons stuck in it – like the raisins in the filling festive favourite. The plum pudding model was consistent with the evidence available at the time, and helped explain the generation of static electricity but was eventually replaced by the Rutherford atomic model in 1911, after Ernest Rutherford discovered the atomic nucleus. However, both Thomson and Rutherford were shockingly silent on whether you should have cream, custard or brandy sauce on your atomic Christmas pudding.

3. The nights draw in and the nights draw out…

21 December brings the Winter Solstice, the longest night of the year. The December solstice occurs because the Earth is tilted on its axis by about 23.5 degrees relative to its orbit around the Sun, meaning different parts of the Earth receive varying amounts of sunlight throughout the year. The length of the shortest day varies depending on your location. For example, in London, the shortest day lasts about 7 hours, 49 minutes and 42 seconds. But do not despair, lovers of the Sun – from 22 December the days start getting longer again!

4. Your Christmas jumper is a meta-material marvel

It might seem like a shapeless, itchy, day-glo horror with a questionable reindeer on the front to you, but to materials scientists Jerome Crassous, Samuel Poincloux and Audrey Steinberger your home-knitted Christmas jumper is a wonder of dazzling complexity. In their jauntily titled study, ‘Metastability of a Periodic Network of Threads: Shapes of a Knitted Fabric’, they take a deep dive into the interplay of friction and fibres which create knitwear’s structure and conclude that by modelling the forces at play, we could learn more about other interwoven networks like bird’s nests and ancient scrolls, as well as helping develop innovative new materials.

5. Watch as your wine defies gravity

If the wine in your Christmas lunch glass of claret appears to be behaving oddly it may not just be because you overdid it on the breakfast Buck’s Fizz. Scientists have long been fascinated by the way wine moves on the inside of a glass and not just because they enjoy a drink as much as many of the rest of us do. The ‘tears’ which form when wine is swilled around the inside of a glass are used by wine buffs to fully appreciate and examine the vintage but also behave in a very unusual way as the different rates of evaporation of the alcohol and water generate capillary action. This means the wine can actually be observed climbing up the sides of the glass. Physicist James Thomson, the brother of Lord Kelvin, first accurately describe the basic mechanism behind the phenomenon in 1855. And while James was less celebrated than his famous younger sibling, he was more fun at parties.

6. And then there was light

If you look closely, you may notice that sparks are flying when your nearest and dearest open their presents on Christmas morning. Due to a phenomenon called triboluminescence, a small amount of light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed. And one of the best ways to generate a triboluminescent effect is to pull or pull apart adhesive tapes. So, when the kids are tearing into their presents and causing general messy mayhem you may be comforted to know that they are also generating tiny magical bursts of light in the process.

7. Santa gets the job done

Physicists at the University of Manchester calculated that by travelling at close to the speed of light Santa’s sleigh can actually deliver his presents to all the planet’s children in just one magical night. The tremendous velocity will mean he is affected by ‘time dilation’ so if we were to look at his watch, it would seem to be ticking more slowly than our own. It’s all down to Einstein’s theory of space, time and light, called special relativity.