There are approximately two billion children (persons under 18) in the
world.
However, since Santa does not visit children of Muslim, Hindu, Jewish or
Buddhist religions (except maybe in Japan) , this reduces the workload for
Christmas night to about 15% of the total, or 378 million (according to the
Population Reference Bureau). At an average (census) rate of 3.5 children
per household, that comes to 108 million homes, presuming that there is at
least one good child in each.
Santa has about 31 hours of Christmas to work with, thanks to the different
time zones and the rotation of the earth, assuming he travels east to west
(which seems logical). This works out to 967.7 visits per second.
This is to say that for each Christian household with a good child, Santa
has around 1/1000th of a second to park the sleigh, hop out, jump down the
chimney, fill the stockings, distribute the remaining presents under the
tree, eat whatever snacks have been left for him, get back up the chimney,
jump into the sleigh and get on to the next house.
Assuming that each of these 108 million stops is evenly distributed around
the earth (which, of course, we know to be false, but will accept for the
purposes of our calculations), we are now talking about 0.78 miles per
household; a total trip of 75.5 million miles, not counting bathroom stops
or breaks.
This means Santa's sleigh is moving at 650 miles per second--3,000 times
the speed of sound. For purposes of comparison, the fastest man-made
vehicle, the Ulysses space probe, moves at a poky 27.4 miles per second,
and a conventional reindeer can run (at best) 15 miles per hour.
The payload of the sleigh adds another interesting element. Assuming that
each child gets nothing more than a medium sized Lego set (two pounds), the
sleigh is carrying over 500 thousand tons, not counting Santa himself. On
land, a conventional reindeer can pull no more than 300 pounds. Even
granting that the "flying" reindeer could pull ten times the normal amount,
the job can't be done with eight or even nine of them--Santa would need
360,000 of them.
This increases the payload, not counting the weight of the sleigh, another
54,000 tons, or roughly seven times the weight of the Queen Elizabeth (the
ship, not the monarch). 600,000 tons travelling at 650 miles per second
creates enormous air resistance--this would heat up the reindeer in the
same fashion as a spacecraft re-entering the earth's atmosphere. The lead
pair of reindeer would absorb 14.3 quintillion joules of energy per second
each. In short, they would burst into flames almost instantaneously,
exposing the reindeer behind them and creating deafening sonic booms in
their wake. The entire reindeer team would be vaporised within 4.26
thousandths of a second, or right about the time Santa reached the fifth
house on his trip.
Not that it matters, however, since Santa, as a result of accelerating from
a dead stop to 650 m.p.s. in 0.001 seconds, would be subjected to
acceleration forces of 17,500 g's. A 250 pound Santa (which seems
ludicrously slim) would be pinned to the back of the sleigh by 4,315,015
pounds of force, instantly crushing his bones and organs and reducing him
to a quivering blob of pink goo and a few white hairs....
Therefore, if Santa did exist, he's dead now.
Merry Christmas.
