2002-12-19

John,

Please reread the Santa story below and note the changes.  In addition to
metricating the story, I corrected some other errors.  Santa Claus does not
have an "e" at the end of Claus.  I changed centrifugal forces to g-forces
at the end.

You may wish to check the edits for correctness, but please realise I tried
to round to rational numbers to make SI look more comprehensible.  If you
like the update, pass it back to whoever sent it to you and pass it on to
everyone on your list.  And remember, if some one complains about the use of
SI, tell them the north Pole is in metric territory and NASA now uses
metric.  Even the all non-American children on Santa's list are in metric
countries, and they form the majority.  The majority rules.

It will be interesting to see if this version circulates as much as the
other is.

John




Is there a Santa?

A little girl named Virginia asked the New York Times if there was a Santa
Claus. The reply is now famous.

Someone thought it would be fun to ask the scientists at NASA the same
question. Here is their reply:

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 seen.

There are 2 000 000 000 children (under 18) in the world. But since Santa
doesn't appear to handle Muslim, Hindu, Buddhist and Jewish children, that
reduces the workload to15 % of the total - 138 000 000 or so. At an average
rate of 3.5 children per household, that's 91 800 000 homes. One presumes
there is at least one good child in each. Santa has 31 h of Christmas to
work with, thanks to time zones and the rotation of the earth, assuming he
travels east to west. This works out to 822.6 visits per second.

This is to say that for each household with good children, Santa has 1 ms to
park, hop out of the sleigh, jump down the chimney, fill the stockings,
distribute the remaining gifts under the tree, eat snacks, get back up the
chimney, get back into the sleigh, and move to the next house.

Assuming that each of these 91 800 000 houses are distributed evenly (which
we know to be false but for the sake of these calculations we will accept)
we are now talking about 1.25 km per household, a total trip of 121.5 Gm
(gigametres), not counting bathroom stops. This means that Santa's sleigh is
travelling at 1000 km/s (kilometres per second), 3000 times the speed of
sound.

For comparison, the fastest man made vehicle, the Ulysses space probe moves
at a poky 44 km/s. The average reindeer runs at 25 km/h (7 m/s). The
sleigh's payload adds another interesting element. Assuming that each child
gets nothing more than a medium sized Lego set (1 kg), the sleigh is
carrying 300 Gg (gigagrams), not counting Santa, who is invariably described
as overweight.

On land, conventional reindeer can pull no more than 150 kg.  Even granting
that "flying reindeer" (see first paragraph) could pull TEN TIMES the usual
amount, we cannot do the job with 8 or even 9. We need 214 000 reindeer.
This increases the weight, not even counting the sleigh, to 350 Gg.  Again,
for comparison this is 4 times the weight of the British liner Queen
Elizabeth II.

350 Gg travelling at 1000 km/s creates an enormous air resistance. This will
heat the reindeer in the same manner as a spacecraft re-entering the earth's
atmosphere. The lead pair of reindeer will absorb 14.3 EW (exawatts) EACH.
In short, they will burst in flame almost instantaneously, exposing the next
pair of reindeer, and creating deafening sonic booms in their wake.

The entire team will be vaporized within 4.26 ms. Santa, meanwhile, will be
subjected to g-forces 17 500.06 times the force due to gravity. A 150 kg
Santa would be pinned to the back of his sleigh by 19.25 MN (meganewtons) of
force.

CONCLUSION: There was a Santa, but he's dead now.










John Nichols  BE, Ph.D. (Newcastle), MIE (Aust), Chartered Professional
> Engineer
> Assistant Professor
> Texas A&M University
> Department of Construction Science
> Langford AC
> Rm: A414   MD 3137
> College Station, TX 77843-3137
>
> Electronic mail:  [EMAIL PROTECTED]
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> -----------------------------------------------------------------
> a fronte praecipitium  a tergo lupi
>
> in front a precipice, behind a wolf
> -----------------------------------------------------------------
>
>

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