How far have we come and how far can we go ?
The USA and Canadian's standard railroad gauge (width between the two rails) is 4 feet, 8.5 inches. That's an exceedingly odd number...it any present day design. So...why this dimension ? Well...because that's the way they built them in England...and the USA and Canadian railroads were built by English expatriates.
OK...so why did the English build them like that? Simple...because the first railway lines were built by the same people who built the first pre-railroad tramways and that's the gauge they used.
Fair enough...bu why did "they" use this gauge than? Because the people who built the tramways used the same jigs and tools that were used for building wagons which used the same wheel spacing.
Okay!!! But 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 the old rutted roads in the firts place ? The first long distance roads built in Europe (and England) were built by Imperial Rome for their legions and those same roads have been used ever since.
And the ruts in the roads ? Roman war chariots first formed the initial ruts...which everyone had to match for fear of destroying their wagons wheels. Since the chariots were made for...or by Imperial Rome, they were all alike in the matter of wheel spacing.
The standard railroad gauge of 4 feet, 8.5 inches derives from the original specifications for an Imperial Roman war chariot.
Specifications 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. Thus...we have the answer to the "original" question.
But now for the extra-terrestrial twist to the story...
When we see a Space Shuttle sitting on the 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 might 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 had to go through a tunnel in the mountains. The SRBs had to fit through the tunnels. The tunnels are slightly wider than the railroads tracks...and the railway track is about as wide as two horses behinds.
So...the major design feature in what could possibly be the world's most advanced transportation system was determined over two thousand years ago by the width of a horse's ass.
Therefore ladies...when we guys look at famale butts...we are not being insensitive...or being what you might call "typical males"...we are actually studying the possiblities and probablities of the implications of the female butt might have two thousand years for now in relations to time travel...really....