# The Naked Scientists Forum

### Author Topic: What forces would Santa experience?  (Read 1959 times)

#### Matthew

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##### What forces would Santa experience?
« on: 21/12/2009 23:30:02 »

Hello Naked Scientists, Merry Christmas!

Now, I'm wondering what length of time our famous friend Santa can potentially spend at each household if there 842 million households with an average of 2.5 children living there in one night?

What velocity/ or speed would he have to travel between each house, with a total distance of 336.8 million kilometres, and what force would be needed to stop the momentum of his sleigh etc. at each house?

(This question does take time and was exceedingly theoretic but stimulating in my science class!)

What do you think?
« Last Edit: 21/12/2009 23:30:02 by _system »

#### Geezer

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##### What forces would Santa experience?
« Reply #1 on: 22/12/2009 01:40:32 »
Well, first we would have to calculate the optimum route. This would be known as "The travelling Santa problem."

Condsidering the number of stops Santa has to make, it might take quite a while to find the best solution.

#### yor_on

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##### What forces would Santa experience?
« Reply #2 on: 25/12/2009 21:33:57 »
That one is in fact a known one to physics.
"

Is There A Santa Claus?

I
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.

II
There are 2 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 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.

III
Santa has 31 hours of Christmas to work with, thanks to the different time zones and the rotation of the earth, assuming hetravels 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 31 hours, plus feeding and 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 pokey 27.4 miles per second - a conventional reindeer can run, tops, 15 miles per hour.

IV
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. Again, for comparison - this is four times the weight of the Queen Elizabeth.

V
353,000 tons traveling at 650 miles per second creates enormous air resistance - this will heat the reindeer up in the same fashion as space crafts reentering 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! "

And then people complain about science being in their ivory towers.
This should amply proof that they are ready to tackle any down to Earth question.

But please, keep it away from the kids. There are enough redeyes as it is.
« Last Edit: 25/12/2009 21:36:01 by yor_on »

#### The Naked Scientists Forum

##### What forces would Santa experience?
« Reply #2 on: 25/12/2009 21:33:57 »