*I. 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, this reduces the workload for
Christmas night to 15% of the total, or 378 million (according to the
Population Reference Bureau). *

*At an average (census) rate of 3.5 children per house hold, that comes
to 108 million homes, presuming that there is at least one good child in
each. *

*II. 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. *

*III. 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). *

*IV. 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 vaporized 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 .001 seconds, would be subjected to
centrifugal 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. *

*Therefore, if Santa did exist, he's dead now.*

Merry Christmas everyone!