Why some things the way they are?
Example
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 specification and wonder what
horse's ass came up with it, 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 at 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.
Just thought I would point this out