Our race against the clock with last-minute gift shopping is nothing compared to the difficulties faced by Santa on Christmas Eve. He must allow time to visit every child on the planet in a single night – so how does he do it?
Santa has to visit approximately two billion children in the world, and assuming there are an average of 2.5 children per household, that makes about 800 million stops on Christmas Eve.
Next, we must work out the distance Santa has to travel. Earth has a surface area of 197 million square miles (to the nearest million), but given most people live on land, only 30% of this area needs to be considered. So assuming the 800 million stops are equally spread across the landmasses, each house occupies about 0.073 square miles. We square-root this area to calculate the distance between each stop, which comes out as 0.27 miles. For 800 millions stops, Santa’s journey on Christmas Eve is therefore about 216 million miles long.
Travelling at 100 mph, for example, this journey would take 2,160,000 hours, or 247 years! Clearly, he must be going much faster to be able to finish in one night.
Luckily, if Santa travels across the International Date Line, in the direction of the Earth’s rotation, he’ll have a generous 48 hours on Christmas Eve to deliver all the presents. This means he has two ten-thousandths of a second per household.
Santa’s sleigh must, therefore, travel at 1,250 miles per second, which is 5,865 times the speed of sound. The only explanation I can think of for how he does it? Good old-fashioned Christmas magic.