Starting from biology, although there are at least 300,000 species of living organisms that have not yet been recorded, it is rather unlikely that we will discover a species of flying reindeer. Continuing now with some statistics, there are approximately 2 billion children worldwide. Subtracting other religions, we end up with about 378 million waiting for a gift. Based on data from the International Population Register, the average is 3.5 children/family, so the visits to be made are to 91.8 million homes.
With only 31 hours of work – due to the time difference and the rotation of the earth – Santa will have to make 822.6 visits per second. He has just over 1/1000th of a second to go from house to house, park the sleigh, drop off the presents and leave.
If we accept that these houses are equidistant, we have a distance of 1.25 km per house, for a total journey of 1.21 million km that he would have to travel. So, it would have to travel at 3,000 times the speed of sound. For example, a normal reindeer does not reach more than 80 km/h.
Now let’s go to the load. With gifts of one kilogram, the sled should weigh about 321,300 tons loaded. Plus a little bit of Santa’s weight. If the latter now eats a piece of pie in each house (91.8 cm in total), his weight rises even more. With such a number, about 214,200 reindeer would be needed to pull the sleigh.
Somehow, we end up with a vehicle with a total weight of 353,400 tons, moving at 1,046 km/sec. This, as aerodynamic as it is, will have incredible wind resistance. The front pair of reindeer will damp 14.3 quadrillion Joules/sec. More simply, they will vaporize instantly, with a deafening noise, leaving the pair behind exposed. The entire flock will be vaporized within 4.26 milliseconds. As for Santa, with his constant stop-starts, he should be able to withstand an acceleration of 17,500.06 times gravity. If he weighs around 100 kg, the 2,107,007 kg of inertia he will experience will make him a decal in his seat.
Conclusion: Fortunately, magic does not happen within the usual framework of natural laws.
Happy birthday and happy new year everyone!