1. There are approximately two billion children (persons under 18) in the(adsbygoogle = window.adsbygoogle || []).push({});

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

second.

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

himself.

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.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Christmas from from an Engineer's Perspective

**Physics Forums | Science Articles, Homework Help, Discussion**