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 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 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 stocking, distribute the remaining

presents under the tree, eat whatever snacks have been left for

him to get back up the chimney 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 or 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 can pull 10 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).

A mass of nearly 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 adsorb 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 426 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 17,000 g's. A 250

pound Santa (which seems ludicrous considering all the high

calorie snacks he must have consumed over the years) 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 :p