(請勿談論政治議題或做人身攻擊)
這是來自於一封朋友forward的網路郵件, 作者不詳, 內容未經考究,
覺得挺有趣的所以post, 當作網路八卦看看吧!!(如有不妥, 煩請版主刪除, sorry!)
美國鐵軌寬度的由來
經濟學經濟學中有個名詞稱為「路徑依賴」，它是類似於物理學中的“慣 性”，一旦選擇進入某一路徑（無論是「好」的、還是「壞」的），就可能對這種路徑產生依賴。
以下美國鐵軌的故事也許有助於我們理解這一概念，並且加深對其後果的印象。
美國鐵路兩條鐵軌之間的標準距離是四點八五英尺。這是一個很奇怪的標準究竟從何而來的？
原來這是英國的鐵路標準，因為美國的鐵路最早是由英國人設計建造的。
那麼為什麼英國人用這個標準呢？
原來英國的鐵路是由建電車軌道的人設計的，而這個四點八五英尺正是電車所用的標準。電車軌標準又是從哪裡來的呢？
原來最先造電車的人以前是造馬車的。而他們是用馬車的輪寬做標準。好了，那麼，馬車為什麼要用這個一定的輪距離標準呢？
因為如果那時候的馬車用任何其他輪距的話，馬車的輪子很快會在英國的老路上撞壞的。為什麼？
因為這些路上的轍跡的寬度為四點八五英尺。這些轍跡又是從何而來呢？
答案是古羅馬人定的，四點八五英尺正是羅馬戰車的寬度。如果任何人用不同的輪寬在這些路上行車的話，他的輪子的壽命都不會長。我們再問：羅馬人為什麼用四點八五英尺為戰車的輪距寬度呢？
原因很簡單，這是兩匹拉戰車的馬的屁股的寬度。故事到此應該完結了，但事實上還沒有完。
下次你在電視上看到美國太空梭立在發射臺上的雄姿時，你留意看，在它的燃料箱的兩旁有兩個火箭推進器，這些推進器是由設在猶他州的工廠所提供的。
如果可能的話，這家工廠的工程師希望把這些推進器造得再胖一些，這樣容量就會大一些，但是他們不可以，為什麼？
因為這些推進器造好後，要用火車從工廠運到發射點，路上要通過一些隧道，而這些隧道的寬度只比火車軌道的寬度寬了一點點，然而我們不要忘記火車軌道的寬度是由馬的屁股的寬度所決定的。
因此，我們可以斷言：可能今天世界上最先進的運輸系統的設計，是兩千年前便由兩匹馬的屁股寬度決定了。
這就是路徑依賴，看起來有幾許悖謬與幽默，但卻是事實。
網路八卦: 美國鐵軌寬度的由來
版主: Lancelot
網路八卦: 美國鐵軌寬度的由來
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我收到的是英文版
內容雷同
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The US standard railroad gauge (distance between the rails) is 4 feet
8.5 inches. That's an exceedingly odd number. Why was that gauge
used? Because that's the way they built them in England, and English
expatriates built the US Railroads. Why did the English build them like
that? Because the first rail lines were built by the same people who
built the pre-railroad tramways, and that's the gauge they used. Why
did "they" use that gauge then? Because the people who built the
tramways used the same jigs and tools that they used for building
wagons, which used that wheel spacing.
Okay! Why did the wagons have that particular odd wheel spacing? Well,
if they tried to use any other spacing, the wagon wheels would break on
some of the old, long distance roads in England, because that's the
spacing of the wheel ruts. So who built those old rutted roads?
Imperial Rome built the first long distance roads in Europe (and
England) for their legions. The roads have been used ever since. And the
ruts in the roads? Roman war chariots formed the initial ruts, which
everyone else had to match for fear of destroying their wagon wheels.
Since the chariots were made for Imperial Rome, they were all alike in
the matter of wheel spacing.
The United States standard railroad gauge of 4 feet, 8.5 inches is
derived from the original specifications for an Imperial Roman war
chariot. And bureaucracies live forever.
So the next time you are handed a spec and told we have always done it
that way and wonder what horse's ass came up with that, you may be
exactly right, because the Imperial Roman war chariots
were made just wide enough to accommodate the back ends of two war
horses.
Now the twist to the story... When you see a Space Shuttle sitting on
its launch pad, there are two big booster rockets attached to the sides
of the main fuel tank. These are solid rocket boosters, or SRBs. The
SRBs are made by Thiokol at their factory in Utah. The engineers who
designed the SRBs would have preferred to make them a bit fatter, but
the SRBs had to be shipped by train from the factory to the launch
site. The railroad line from the factory happens to run through a
tunnel in the mountains. The SRBs had to fit through that tunnel. The
tunnel is slightly wider than the railroad track, and the railroad
track, as you now know, is about as wide as two horses' behinds.
So, a major Space Shuttle design feature of what is arguably the
world's most advanced transportation system was determined over two
thousand years ago by the width of a Horse's ass.
And you thought being a horse's ass wasn't important ??
內容雷同
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練一下閱讀能力吧!
The US standard railroad gauge (distance between the rails) is 4 feet
8.5 inches. That's an exceedingly odd number. Why was that gauge
used? Because that's the way they built them in England, and English
expatriates built the US Railroads. Why did the English build them like
that? Because the first rail lines were built by the same people who
built the pre-railroad tramways, and that's the gauge they used. Why
did "they" use that gauge then? Because the people who built the
tramways used the same jigs and tools that they used for building
wagons, which used that wheel spacing.
Okay! Why did the wagons have that particular odd wheel spacing? Well,
if they tried to use any other spacing, the wagon wheels would break on
some of the old, long distance roads in England, because that's the
spacing of the wheel ruts. So who built those old rutted roads?
Imperial Rome built the first long distance roads in Europe (and
England) for their legions. The roads have been used ever since. And the
ruts in the roads? Roman war chariots formed the initial ruts, which
everyone else had to match for fear of destroying their wagon wheels.
Since the chariots were made for Imperial Rome, they were all alike in
the matter of wheel spacing.
The United States standard railroad gauge of 4 feet, 8.5 inches is
derived from the original specifications for an Imperial Roman war
chariot. And bureaucracies live forever.
So the next time you are handed a spec and told we have always done it
that way and wonder what horse's ass came up with that, you may be
exactly right, because the Imperial Roman war chariots
were made just wide enough to accommodate the back ends of two war
horses.
Now the twist to the story... When you see a Space Shuttle sitting on
its launch pad, there are two big booster rockets attached to the sides
of the main fuel tank. These are solid rocket boosters, or SRBs. The
SRBs are made by Thiokol at their factory in Utah. The engineers who
designed the SRBs would have preferred to make them a bit fatter, but
the SRBs had to be shipped by train from the factory to the launch
site. The railroad line from the factory happens to run through a
tunnel in the mountains. The SRBs had to fit through that tunnel. The
tunnel is slightly wider than the railroad track, and the railroad
track, as you now know, is about as wide as two horses' behinds.
So, a major Space Shuttle design feature of what is arguably the
world's most advanced transportation system was determined over two
thousand years ago by the width of a Horse's ass.
And you thought being a horse's ass wasn't important ??
