每逢年末，全球成千上萬的孩子們都急切地等待著圣誕老人能送來禮物和美好的祝福。但如果圣誕老人來不了怎么辦？要是今年負責拉雪橇的馴鹿集體感染了類似瘋牛病的“瘋鹿病”，圣誕老人被迫取消節日怎么辦？其結果會是一場大災難。

不過，要是讀者中有小朋友的話，告訴你們一個好消息：北極官方表態稱，今年圣誕老人的雪橇做了一些升級處理，萬一馴鹿病倒，還可以利用飛機燃油運行。而且由于全球石油市場供過于求，即使馴鹿想照常執行任務，圣誕老人也有可能給它們放一晚上假，選擇燒油出行。

那么，圣誕老人在24日晚上飛遍各地究竟需要花多少油？

這個答案相當復雜，牽涉到許多很重要因素，比如我們既不知道圣誕老人的飛行路線，也不知道雪橇的形狀和飛行速度，更不清楚所有禮物的重量，不過，我們可以來憑經驗大膽地推測一下。

一桶原油的標準容量是42加侖（約合159升），通常可制成多種產品。平均每桶油有51%會煉成汽油，另有12%最終可用作航空燃油。假設圣誕老人將使用的是標準航空燃油，按比例來算，每提煉一加侖這類燃油需要消耗約8加侖原油

接下來，我們需要大致了解圣誕老人的油耗水平。一加侖燃油能飛多少英里？現在還不知道雪橇的具體重量和形狀，但我們或許可以把它想象成一輛外觀看上去像雪佛蘭SUV、但能像C-5 “銀河”軍用運輸機一樣裝貨，速度又能達到F-22“猛禽”戰斗機水平的混合體。按戰斗機和C-5運輸機的標準來看，每一加侖燃油可供其飛行0.1-0.5英里（0.16-0.8公里）。而波音747這樣的大型寬體客機每飛行一英里需消耗約5加侖燃油。

當然，那些飛機都比圣誕老人的雪橇大得多（想象一下可憐的紅鼻子馴鹿魯道夫拉著一架波音787飛機是什么場景）。而一架小型商務噴氣機Learjet每消耗約一加侖燃油可以飛行2.75英里。一架Piper Cub輕型飛機每耗約一加侖燃油飛行15英里。如果提高飛行速度，圣誕老人的燃油利用率就會下降。要在一夜之間拜訪全世界的孩子們，他需要的速度應該比Piper Cub的每小時65節快得多。單說起飛，他的速度就要達到每小時約180英里。考慮到雪橇的設計者可能不大了解有關飛機怎樣產生升力的伯努利原理，起飛速度恐怕要更高。因此Suburban車的大小可能最適合圣誕老人的雪橇，至于油耗，估計每加侖燃油（約8加侖原油）能飛行約5英里吧。

正好眼下能源市場動蕩，睿智的投資者迎來了千載難逢的良機。

雖然主流媒體還在說油價已經跌得不知道底在哪里，但高明的石油投資者已經開始為下一輪出手做好充足準備。現在來算算圣誕老人到底需要飛多遠？全球約有73億人，根據每家五口人計算，老人需要走訪全球15億個家庭。當然了，并非所有人都過圣誕節，可無論是否基督徒，很多人都重視這個節日。一些估算數據顯示，全球約45%的人口慶祝圣誕，意味著圣誕老人要拜訪約6.75億個家庭。按每平方英里約有7戶人家，并且這些過節的家庭居住比較集中（可以合理地推測，同一宗教信仰的人一般聚居在一起）推算，圣誕老人得走遍地球9400萬平方英里的范圍。

對圣誕老人而言，如何以最高效率走訪6億多家庭是一個非常復雜的數學問題。假設他希望每平方英里都以對角線軌跡飛過（根據勾股定理需要飛行1.41英里），而這些家庭又按比例平均分布在以一英里見方的土地上，圣誕老人要盡量高效地探訪每一平方英里的人家就必須飛過2.41英里以上距離。（可以用多種數學程式建模，根據人口分布計算哪條飛行路線的效率最高，這只是基于上述假定前提做出的合理估算。）

因此，若要將禮物成功派送給世界各地的孩子，圣誕老人就得飛越大概2.26億英里。前提還是盡量縮短在每家的逗留時間（一到地方就必須迅速放下禮物），而且每次起飛都不要加油。

根據我們上面計算出的5英里/加侖的油耗，圣誕老人一年一度的圣誕任務需要耗費約4500萬加侖燃油。當前現貨市場的燃油價格正處于歷史低位，約為1.20美元/加侖，算下來圣誕老人飛行一晚上的燃油成本將近5400萬美元。我們再仔細想想，也許該讓那八只馴鹿停止吃草準備開工了。（財富中文網）

譯者：Pessy

審校：夏林

Every year around the world, hundreds of millions of children wait anxiously for Santa Claus to arrive and bring presents and good cheer. But what if Santa never came? What if this year the reindeer all fall ill, perhaps due to Crazy Reindeer disease (the analog to Mad Cow) and Santa is forced to cancel Christmas? The result would be devastating.

Fortunately, for any children reading, official word from the North Pole is that Santa’s sleigh has some new upgrades this year that allow it to run on good old fashioned jet fuel if the reindeer fail. And with the current glut of oil around the world, fuel prices are so affordable that even if the reindeer are feeling up to their usual task, Old Saint Nick might just give them the night off and choose to fly with fuel nonetheless.

So how much oil does Santa need for his rounds on the night of the 24th?

Well the answer is complicated by a number of factors most importantly, we just don’t know a lot of about Santa’s rounds, the shape of the sleigh, the air speed of the craft, or the weight of all those presents. But, we can take some educated guesses.

One 42 gallon barrel of oil is typically used to make a variety of different products. About 51 percent of the average barrel ends up being used for gasoline, while 12 percent ends up being used for jet fuel. Let’s assume then that Santa’s going to use standard jet fuel, and that 12 percent ratio holds – so for each gallon of jet fuel, we need around 8 gallons of oil. Recognizing that the byproducts of a processed barrel of oil are greater than the original 42 gallons, this 2:1 ratio is still a good place to start as a rough rule of thumb.

Next we need to get a rough idea of Santa’s fuel economy. How many miles does he go on a gallon of jet fuel? It’s not clear how much Santa’s sleigh weighs, or what it is shaped like, but we can probably envision it as something like a cross between a Suburban, a C-5 Galaxy fright aircraft, and an F-22 Raptor fighter jet. The sleigh looks blocky like a Suburban, carries about the same level of cargo as much as C-5 might, yet has the speed of a fighter jet. The fighter jet and c-5 achieve a fuel economy around the range of 0.1 miles per gallon to 0.5 miles per gallon. A 747 for instance burnsaround 5 gallons of fuel per mile.

But of course, those aircraft are all much larger than Santa’s sleigh. (Imagine poor Rudolph trying to pull a Dreamliner!) A Lear Jet uses around 1 gallon of fuel per 2.75 miles (based on a speed of 465 knots or 535 miles per hour). A Piper Cub uses about 1 gallon per 15 miles. Santa’s fuel economy is going to fall offthe faster he goes, and to get to all the children of the world in one night, he is going to need to go a lot more than the Piper cub’s 65 knots per hour. Just to take off, Santa is going to need to hit about 180 miles an hour, and probably more than that given the sleigh designer’s seem to have a weak grasp onBernoulli’s principle. Thus the Suburban is probably a good size comparison for Santa’s sleigh, and one might estimate the sleigh gets about 5 miles to 1 gallon of jet fuel (8 gallons of oil).

The current market turmoil has created a once in a generation opportunity for savvy energy investors.

Whilst the mainstream media prints scare stories of oil prices falling through the floor smart investors are setting up their next winning oil plays.Now how far does Santa need to go? There are around 7.3 billion people in the world, which works out to around 1.5 billion households around the planet based on around 5 people per household. Now not everyone celebrates Christmas of course, but many Christians and non-Christians alike do. By some estimates, perhaps 45% of the world’s population celebrates Christmas. That means that Santa needs to visit about 675 million households. With about 7households per square mile, and assuming that households celebrating Christmas are clustered (which seems logical given religious clustering), that means that Santa has to cover around 94 million square miles of households.

The most efficient mechanism for Santa to cover these households is a very complex mathematical problem. But assuming Santa wants to fly diagonally over each square mile (for a distance of 1.41 miles based on the Pythagorean Theorem), and households are on average distributed proportionally across this each 1 mile block, then Santa will have to fly over 2.41 miles of ground to cover each square mile as efficiently as possible. (You can use a variety of mathematical algorithms to model the most efficient flight path depending on population dispersion – this is just a reasonable approximation based on the assumptions outlined above).

As a result, Santa needs to travel around 226 million miles to deliver all of the presents to the world’s children. This assumes minimal idle time on each rooftop (he’s got to scarf down those cookies quickly), and abstracts away from the extra fuel needed for each takeoff.

Given our 5 miles per gallon of jet fuel efficiency calculated above, that means Santa needs around 45 million gallons of jet fuel for his annual voyage. With jet fuel going for around $1.20 a gallon right now on the spot market, and prices lookinghistorically low, this puts the total fuel cost of Santa’s journey at a bit less than $54 million for one night. On second thought, maybe it’s time to break out the hay for those 8 reindeer.

譯者：Pessy

審校：夏林