Sunday, December 30, 2007

santa impossible

thanks to kevin smith from my local astronomy club, NOVAC for posting this on our message board:


According to a number of references, the world's current population stands at something just over 6 billion. For this analysis assume only Christians believe in Santa and he, therefore, only visits Christian households on Christmas Eve. Several census and survey reports put Christianity at about 33% of the world's population, or roughly 2 billion people. Figuring 4.5
people per household, there are approximately 445 million Christian households distributed around the globe.

Thanks to different time zones and the earth's rotation, traveling east to west Santa has 31 hours of Christmas to work with. With 31 hours to visit 445 million homes, Santa must visit
3,987 homes per second. So for each Christian household with good children, Santa has about 2/1000th of a second to park, hop out of the sleigh, jump down the chimney, fill the stockings, distribute presents under the tree, eat whatever snacks have been left, get back up the chimney, back into the sleigh, and move on to the next house.

Assuming that each of these 445 million stops are evenly distributed around the earth (which, of course, we know to be false but for purposes of our calculations we will accept), we are now talking about 0.17 miles per household, or a total trip of about 75.5 million miles. This means that Santa's sleigh is moving at 650 miles per second, or 3000 times the speed of sound. For purposes of comparison, the fastest man-made vehicle, the Ulysses space probe, moves at a miserably slow 27.4 miles per second; a conventional reindeer can run, at tops, 15 miles per hour.

The payload on the sleigh adds another interesting element. Assuming that each child gets nothing more than a medium size Lego set (2 pounds), the sleigh is carrying 321,300 tons, not counting Santa who is invariably described as overweight. On land, conventional reindeer can pull no more than 300 pounds. Even granting that "flying reindeer" could pull ten times the normal amount, we cannot do the job with eight, or even nine reindeer. No, we need 214,200 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 ocean liner, the Queen Elizabeth.

353,000 tons traveling at 650 miles per second creates enormous air resistance, which will heat the reindeer, sleigh, gifts and Santa in the same fashion as a spacecraft reentering the earth's atmosphere. The lead pair of reindeer will each absorb 14.3 QUINTRILLION joules of energy.per second! In short, they will burst into flame instantaneously, exposing the reindeer behind them to the same fate. The entire reindeer team will be vaporized within 4.26 thousandths (0.00426) of a second. Santa, meanwhile, will be subjected to centrifugal forces 17,500 times gravity. A 250 pound Santa, which seems ludicrously slim, would be pinned to the back of his sleigh by 4,375,000 pounds of force per square inch just before, like his reindeer, he too is vaporized.

In conclusion, if Santa ever did deliver presents on Christmas, he's now very, very dead.

No comments: