Thursday, December 07, 2006

SANTA CLAUS: AN ENGINEER'S PERSPECTIVE


Most of us either work with, or know, at least one engineer. I got to work this morning and found this memo from one of the engineers that I work with.

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 (except maybe in Japan) 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.

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 around1/1000th of a second to park the sleigh, hop out, jump down the chimney, fill the stockings, 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 onto 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. 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 "flying" 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).

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 re-entering 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 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 m.p.s. in .001seconds, would be subjected to acceleration 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.

Therefore, if Santa did exist, he's dead now. Merry Christmas.

Then I found this on the Internet (seems that the engineer in question was indulging in a little plagiarism!)

Santa Claus: An Engineering Analysis REBUTTAL
To understand this joke, click here to see the original joke, Santa Claus: An Engineering Analysis
If people are going to attempt to apply science to the question of Santa, the least they can do is to get it right. The so-called "Engineer" that wrote the paper suggesting that Santa Claus is dead had it all wrong.

A) In paragraph 5, the Engineer states that "600,000 tons traveling at 650 miles per second creates enormous air resistance." Assuming that this true, it may well be that the reindeer are protected by some sort of heat shield, which is the basis of the "red nose" legend. More to the point, the "air resistance" theory is a vast oversimplification, and a sloppy one at that. In comparing a parachute to a javelin, one can see that there is no simple, direct, predictable relationship between the weight of an object and its air resistance. The air resistance theory completely ignores many possible configurations of Santa's team that could greatly reduce air resistance.

Paragraph 5 is invalidated all the more when one considers paragraph 1, which states that most of the 300,000 unclassified species on the earth are insects and microorganisms. This suggests that it is overwhelmingly probable that any unknown species (such as flying reindeer) is extremely small (possibly even microscopic), with correspondingly low air resistance.
Also, note that various small species (e.g. bumblebee) have been known to accomplish feats of aviation that have proven quite difficult for science to explain. Furthermore, many small species (e.g. ants) possess strength that is immense proportional to their size. Also note that every known species has a body structure capable of withstanding whatever stresses are created at the top speed at which the creature is capable of traveling.

Therefore, contrary to the Engineer's conclusion, the possible existence of unknown, very small, very strong, flying creatures is indicated, and all of the Engineer's statistics on the mass, speed, capacity, and durability of standard Reindeer are therefore irrelevant.

B) If we accept the notion that Santa moves from East to West (an assumption that the Engineer makes in Paragraph 3) then we must also assume that he is moving in a vaguely North-South traversing path as he works his way West. This implies that, if he chose to, he could make several stops at the Pole to re-load the sleigh, and therefore it is not necessary for him to carry the entire payload all at once as described by the Engineer.

The reader may raise the objection that most depictions of Santa's procedures include a single annual departure from the Pole. However, one must also consider that these same depictions contain many other omissions and simplifications, such as the implication that Santa spends several minutes on each delivery. Even using unrealistically favorable figures, this is mathematically impossible. This and other examples force us to consider these depictions to be strictly allegorical. This makes sense, since a documentary would not be much fun for the target audience.

C) Consider that most chimneys are too small to accommodate an average-sized man, let alone a 250 (plus) pound man. This implies that Santa has a way of entering and exiting dwellings through access paths much smaller than those that would otherwise be required. If the same technique that Santa uses to transport himself and the gifts past locked doors also decreases mass (or makes it irrelevant), then the payload problem is completely solved. (Note that any sufficiently advanced technology is indistinguishable from magic.)

D) If we accept the notion that Santa's intelligence gathering is good enough for him to determine who is bad/good, sleeping/awake etc., then it stands to reason that Santa also knows enough about health problems, travel plans, hurricanes, floods, drive-by shootings, fires, volcanoes, earthquakes, bus crashes, burglaries, etc. etc. etc. to be able to defer or advance some of his deliveries for days or even weeks, thus considerably extending the 31 hour time limit (as mentioned by the Engineer in paragraph 3) for perhaps 3 to 5 percent of children.

E) In paragraph 3, the Engineer admits to the assumption that Christian homes are randomly distributed over the entire surface of the planet. In reality, a majority of the earth's surface is covered by the oceans, and a great portion of what is left is covered by mountains, deserts, forests, jungles, glaciers, smaller bodies of water, and other natural and man-made features that render the space uninhabitable by humans -- or at least extremely sparsely populated by Christians, who largely tend to live in communities with homes placed in neat rows on level ground, or in densely populated vertical blocks in urban areas.

Also, many families tend to gather for the Holidays, thus decreasing the number of Christian dwellings that are actually occupied on December 24-25. Therefore, the aforementioned assumption leads to an *staggering* overestimate of the number of times Santa must travel distances exceeding 60 feet. Also note that this more realistic model includes trans-oceanic voyages during which Santa could take a "bathroom break."

F) In paragraph 3, the Engineer says that Santa has a very short time in which 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. "In the previous paragraph, I dispensed with the notion that Santa must actually park and exit the sleigh, enter and exit the dwelling, and then enter and drive the sleigh for each delivery. As far as the snacks go, it is clear that between the households where the parents eat the snacks prior to Santa's arrival and the households that don't leave snacks at all, Santa has to deal with a snack in only a small proportion of cases. This means that at every stop Santa must, at a minimum, fill stockings and distribute gifts. The other tasks are performed in much smaller proportions.

G) In paragraph 2, the Engineer presents the assumption that roughly 10 children out of 35 are "good." Given my personal observations, I conclude that this would lead us to overestimate of the number of Christian households containing at least one "good" child by an order of magnitude at the absolute minimum. This, more than anything else, decreases the number of stops that Santa must make.

In conclusion - all of the Engineer's calculations are based on figures that are massively skewed, always choosing the worst-case value. The distances to be traveled, the number of stops to be made, the amount of work to be performed, and the amount of cargo to be carried are all FAR smaller than the Engineer estimates.

Santa has NOT been burned to a cinder, he has NOT been squished by the acceleration of his sleigh, and (though I'm quite certain he won't be visiting that Engineer's house,) Santa Claus IS coming to town!

3 comments:

Anonymous said...

Ok. I can't believe I just read most of this. But thank you for posting it so that I know there is still a Santa Claus. And that engineer is getting COAL!

Anonymous said...

A couple of facts that were clearly overlooked:

1) It's quite obvious that in addition to loading gifts on his sleigh, Santa must attach a 17.4 ton cone-shaped portion of glacial ice to the front of his vehicle. This provides the necessary cooling for the reindeer and is used as a crude heat shield. This may explain the gradual disappearance of the polar ice caps on the planet.

2) My wind tunnel tests of the above configuration, combined with high-speed digital photography taken on Christmas eve, indicates that Santa's secret is that the sleigh never actually stops, it just drops santa off with the gifts for each house and continues at the 650 mile-per-second speed around the planet. It retrieves Santa with a sophisticated bungee-cord mechanism that picks him off the rooftop and slowly accelerates him from standstill to 650 miles-per-second in 10 or 12 seconds, which is within the design paramaters of his (red fur lined) g-suit.

Anonymous said...

Okay, you are all missing the point. I'm an Engineer with a Master's Degree in Engineering and also attended Star Fleet Academy so I believe I know what I'm talking about. First of all you are assuming Santa has to follow the laws of classical Newtonian Physics but he doesn't. He uses Einstein's Physics, i.e. Light is also a wave, Time is Relative, Quantum Mechanics means Mass=Engery/Speed of Light**2. Matter is made up of Quarks and Leptons, which are made up of light, which leads to the paradox, is it a particle or a wave. So you're thinking that Santa is made up of particles but he, the sleigh, presents, and reindeer are really made up of waves. So he can travel at the speed of light or 186,282 miles per second. So at .78 miles/household, Santa can visit 238,823 houses per second and visit those 108 million homes in little over 7.5 hours. If the average distance between the sleigh, Christams tree, stockings, and milk and cookies is 30 ft it would require an additional .29 hrs. Plus add 15 minutes for bodily needs yields...(and you wondered where the 8 hour workday originated). But Santa comes from Einstein's Space-Time Continuum so yesterday, today, and tomorrow ocurr at once, which means this whole discussion is irrelevant.