Ok so this post isn't especially relevant to cars and motoring but Santa does use a vehicle, so that counts, right? So I ask - is there really a Santa Claus?
1) No known species of reindeer can fly. BUT there are 300,000 species of living organisms yet to be classified, and while most of these are insects and germs, this does not COMPLETELY rule out flying reindeer which only Santa has ever seen.
2) There are 2.5 billion children (persons under 18) in the world. But, since Santa doesn't appear to handle the Muslim, Hindu, Jewish and Buddhist children, that reduces the workload to 15% of the total - 378 million according to the Population Reference Bureau. At an average census rate of 3.5 children per household the world over, that's 91.8 million homes. One presumes there's at least one good child in each.
3) Santa has 31 hours of Christmas to work with, thanks to the different timezones and the rotation of the earth, assuming he travels east to west (which seems logical). This works out to 822.6 visits per second. This is to say that for each Christian household with good children, Santa has 1/1000th second to park, hop out of the sleigh, jump down the chimney, fill the stockings, distribute the remaining presents under the tree, eat whatever snacks have been left, get back up the chimney, get back into the sleigh and move on to the next house. Assuming that each of these 91.8 million stops are evenly distributed around the earth (which, of course we know to be false, but for the purposes of our calculations we will accept), we are now talking about 0.78 miles per household, a total trip of 75.5 million miles, not counting stops to do what most of us must do at least once every 31 hours, plus feeding etc etc.
This means that Santa's sleigh is moving at around 650 miles per second, 3,000 times the speed of sound. For the purpose of comparison, the fastest man-made vehicle, the Ulysses space probe, moves at a poky 27.4 miles per second - a conventional reindeer can run, tops, 15 miles per hour.
4) The payload on the sleigh adds another interesting element. Assuming that each child gets nothing more than a medium-sized lego set (2 pounds), the sleigh is carrying a minimum of 321,300 tons, not counting Santa, who is invariably described as overweight. On land, a conventional reindeer can pull no more than 300 pounds. Even granting that "flying reindeer" (see point #1) could pull ten times that amount, we cannot do the job with eight or even nine. We need 214,000 reindeer. This increases the payload - not even counting the weight of the sleigh - to 353,430 tons. Again, for comparison, this is four times the weight of the QE2.
5) 353,400 tons travelling at 650 miles per second causes enormous air resistance - this will heat the reindeer up in the same fashion as a spacecraft re-entering the earths' atmosphere. The lead pair of reindeer will absorb 14.3 quintillion joules of energy. Per second. Each. In short, they will burst into flame almost instantaneously and vaporise, exposing the reindeer behind them, and creating deafening sonic booms. This would wake people up, and the reindeer team would be reduced to ashes in a mere 4.26 thousandths of a second. Santa, meanwhile, will be subjected to combined forces some 17,500.06 times greater than gravity. A 250 pound Santa (which, lets be honest, seems ludicrously slim) would be pinned to the back of his sleigh by 4,315,015 pounds-per-square-foot of force.
In conclusion - if Santa ever DID deliver presents on Christmas Eve, he's long dead.