This is old but funny.
SANTA STATISTICS:
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 billion children (persons under 18) in
the world. BUT because 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 Population Reference Bureau. At an average
(census) rate of 3.5 children per household, 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 time zones 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 of a 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 .78 miles per household, a total trip of 75-1/2
million miles, not counting stops to do what most of
us must do at least once every 3.1 hours, plus feeding, etc.
This means that 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 on earth,
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 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" (see point #1) could
pull TEN TIMES the normal amount, we cannot do the job
with eight, or even nine. We need 214,200 reindeer. This
increases the payload -- not even counting the weight of the
sleigh -- to 353,430 tons.
5) 353,000 tons travelling at 650 miles per second
creates enormous air resistance -- this will heat the reindeer
up in the same fashion as spacecrafts re-entering the
earth's 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, exposing the reindeer behind them, and
create deafening sonic booms in their wake. The entire
reindeer team will be vaporized within 4.26 thousandths
of a second. Santa, meanwhile, will be subjected to centrifugal
forces 17,500.06 times greater than gravity. A 250-pound
Santa (which seems ludicrously slim) would be pinned to the
back of his sleigh by 4,315,015 pounds of force.
In conclusion: If Santa ever DID deliver presents on
Christmas Eve, he's dead now.