From an email, it's interesting...
> SANTA CLAUS: An Engineer's Perspective
>
> 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 calcu-
> lations), we are now talking about 0.78 miles per house-
> hold; 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 traveling at 650 miles per second crates
> 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 650 mps 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.
>
> V.
>
> Therefore, if Santa does exist, he's dead now
> SANTA CLAUS: An Engineer's Perspective
>
> 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 calcu-
> lations), we are now talking about 0.78 miles per house-
> hold; 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 traveling at 650 miles per second crates
> 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 650 mps 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.
>
> V.
>
> Therefore, if Santa does exist, he's dead now