IP: Christmas -- An Engineer's Perspective

[Dave Farber <farber () cis upenn edu>]

Old , I think, but fun

From: StuckerH () aol com
Date: Thu, 17 Dec 1998 15:40:38 EST

Dear Prof. Farber:

Thought you might find this amusing.

Yours,
Hal Stucker

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SANTA CLAUS:  AN ENGINEER'S PERSPECTIVE

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 (except maybe in Japan) 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
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 onto 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 traveling 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 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 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.

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

MerryChristmas.