The science behind Rudolph’s red nose

It is Christmas Eve and Santa and his team are getting ready to deliver gifts to children all around the world. If you are wondering just how he does it, you are not alone; here are some of the questions sent in by children with equally curious minds. The first question comes from four-year-old Harper.

Why is Rudolph’s nose so bright and red?

Reindeer usually don’t have any parts of their body that glow, but some other animals do, like jellyfish and fireflies. We call this bioluminescence. Scientists think that somehow the DNA from one of these animals got injected into Rudolph’s nose, making it glow just like these other animals do.

Esme, 8, would like to know…

If it is possible for the sleigh to fly without reindeer?

Santa’s sleigh is made of a super-light, but strong material, and it has retractable wings that can help create the right air pressure below the sleigh, providing some of the lift needed to keep it airborne. However, the sleigh cannot get into the air without the help of the reindeer; they provide the thrust.

Seán Mulreid is 5 and a half and he has been thinking about what Santa wears on his head...

How does Santa’s magic hat work?

Santa’s hat is a remote control, helping him coordinate the sleigh, the reindeer, and the travel. Scientists now believe that the hat contains probes that can pick up tiny electrical signals in different parts of Santa’s brain, so that he is controlling the hat with his mind. However, if Santa loses his hat, he can still control the sleigh with manual controls and instruct the reindeer with his voice.

Seven-year-old Matthew has been wondering…

How does Santa get down the chimney and how does he get into houses that have no chimney?

The famous scientist Albert Einstein came up with a theory that explains just how Santa does it; Einstein’s theory of relativity says that any object travelling at extremely high speeds will change size and shape.

Effectively, when Santa travels at super speeds, he shrinks (along with the sleigh and the reindeer). In order for Santa to fit down the chimney, he has to keep moving at fairly high speeds and this keeps him small and stretched out like spaghetti, making it easy for him to slip in and out of chimneys. When there is no chimney in the house, it is no problem for Santa in this super small and stretchy state, as he is thin enough to fit through the keyhole.

Eight-year-old Aoife, from Dublin, would like to know …

How does Santa never get caught?

Many children have tried, and failed, to catch Santa as he delivers their presents. The reason he doesn’t get caught is because he is moving so fast, although he does like to slow down time briefly, to give him enough time to eat the treats you leave out. And finally, twins Eva and Dylan would like to know…

How old is Santa?

Nobody knows exactly how and it is likely that the man himself stopped counting a long time ago. Travelling at high speeds, like he does on Christmas Eve, actually slows down time, which keeps Santa young.