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Christmas from from an Engineer's Perspective

  1. Dec 23, 2005 #1
    1. 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 household, that
    comes to 108 million homes, presuming that there is at least one good child
    in each.

    2. 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

    This is to say that for each Christian household with a good child, Santa
    has around 1/1000 of a second to park the sleigh, hop out, jump down the
    chimney, fill the stockings, and 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 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 -- 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.

    3. 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

    On land, a conventional reindeer can pull no more than 300 pounds. Even
    granting that the 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).

    4. 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 reentering 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 to 650 mph in 0.001 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.

    5. Therefore, if Santa did exist, he's now dead.
  2. jcsd
  3. Dec 23, 2005 #2
    Poor Santa. Didn't even live till retirement.
  4. Dec 23, 2005 #3


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    Gold Member

    Rumor has it that Santa has hired... OTHER SANTAS!!!!! And theres a whole farm of reindeer to act as his fleet....
  5. Dec 23, 2005 #4
    You need a sixth clause (pun intended):
    Santa can defy the laws of the universe as we know it.
    Ya 6 santa's running around ought to do it. You can do the math.
    Last edited: Dec 23, 2005
  6. Dec 23, 2005 #5


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    Staff: Mentor

    I'm glad you posted this, I was going to dig it out of my old files, but hadn't gotten around to it yet. Even though it's been around for years, it still makes me laugh.
  7. Dec 23, 2005 #6
    oooh someone doesn't read the PF blog! I'm telling
  8. Dec 23, 2005 #7


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    Staff: Mentor

    It's in the blog? Of course I read it there... This was just a test to see if "you" were reading. :redface:

    Anyway, found the original source - Is There A Santa Claus? by Richard Waller
    Originally published in Spy magazine, January 1990.

    My link to great Santa stuff is dead. :cry:
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