2. When we see the space shuttle in the launch tower, we can notice the two auxiliary fuel tanks attached to the main big one.

3. They are built in Utah by the renowned company ATK Thiokol, which also makes missiles. The engineers that designed them would have preferred they were larger, but these tanks...

4. … have to be carried on a train up to the launch site, in Cape Canaveral. In order to do it, they have to be taken across and thorugh the Rocky Mountains, but tunnels do not allow bigger tanks…

5. Then, why are tunnels this big? Because their size depends on the width of the convoy, which in turn depends on the gap between the rails. In the USA, the gauge is 4 feet 8,5 inches wide (1,4 m.) But, why was this measure adopted?

6. Because North-American railroads were built by British engineers, same as British railways. Good, but why railways in Great Britain are that wide? That is because the first railway lines were designed by the same engineers that made street-cars, trams, which were already using that gauge.

7. The first tramcar makers were the ones who were previously making wagons, and were using the same methods and the same tools. But, why would carts use that width standard?

8. Because wheel tracks in old Europe were already marked and any other measure would have caused axe breakage. The thing is that those wheel tracks had been marked by the Romans in the countless roads that legionaries had built to move quickly to and fro. Ok, but again, why that width?

9. Because Roman wagons were made with such a size to prevent the haunches of horses from bumping into each other while galloping.

10. So, a design limitation in the world’s fastest and most sophisticated means of transport is brought about by the width of a horse’s backside!

11. the World is designed using the butt!!