Hello, Santamory here! You know, the one in charge of all the science and technology here at the North Pole.

Now I know many of you have seen images of Santa’s sleigh – some of you may have even had a go at designing you own version. But I’m gonna let you in on some of the secrets.

With his sleigh, Santa flies to every single house across the globe in a single night. That’s got to be one pretty aerodynamic toboggan, right? Well for many years it wasn’t. The reindeer had to work extremely hard to pull the original clunky sleigh through the air.

Then one day some clever elves worked out that the air resistance, or should I say drag, on the sleigh was pretty high. When something like an aeroplane – or a sleigh – moves through the air, every part of it generates drag – this makes it harder for it to travel forward. It’s the job of designers – or in my case, elves – to make sure that the shape of a vehicle generates as little drag as possible. And luckily Elves are brilliant designers. And a good job too.

The most aerodynamic shape in the world is a drop of rain when it’s falling – the front is a very big semicircle, then it smoothly forms a point. You will see the same type of shape on an aircraft wing – the front is a semicircle, and then the wing tapers into a very aerodynamic form, so the airflow nicely follows the shape.

On the other hand, shapes that are jagged or non-streamlined create a lot of drag since they cause the flow of air to change suddenly and make the air push up against the object. This is why airplanes and cars are often curved and smooth – not flat fronted like a house – because the less drag a vehicle creates, the less power you’re going to need to move.

Now over the last year, the elves have been playing around with all of this to try and create a more modern design for Santa’s sleigh. We experimented with teardrop shapes, creating a more smooth and sleek sleigh that looked more like a sports car than a chair on skis. All those smooth lines eliminated 90 percent of the drag created by the old sleigh design, allowing air to flow more smoothly around. In fact, the new sleigh is so aerodynamically sound that it can handle supersonic speeds.

We also thought of a covered cockpit, so that Santa doesn’t get cold while traveling through the chilly stratosphere, as well as a stealth feature, ensuring that even the most eagle eyed kids can’t see him coming!

But Santa didn’t like any of these ideas – he’s still quite attached to the old sleigh. So we’ve had a go at adapting it to help him get around a little quicker. But I’ll tell you about that next time.

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The Science of Christmas with support from Institute of Physics, The Royal Aeronautical Society and The Institution of Engineering and Technology.