The standard distance between the two rail rails of the US Railway is four or five feet. This is a very strange standard, what is it coming? It turns out that this is the UK's railway standard because the US railway is built by British. So why is the British use this standard? The original British railway is designed by the people who built tram tracks, and this four o'clock is the standard used by tram. Where is the tram rail standard come from? It turned out that the person who was first carried out was previously a horse. And they are used to use the carriage of the routine. Ok, then why should the carriage use this certain wheel distance standard? Because if the carriage at that time, the wheels of the carriage will soon hit it on the old man of the UK. why? Because the width of the ruthenia on these roads is four or five feet. What is these ruthenies come from? The answer is an ancient Roman, four o'clock, four or five feet is the width of the Roman chariot. If anyone is driving on these roads with different wheels, his life is not a long life. Let's ask: Why did the Romans use four o'clock eight or five feet as the spacing width? The reason is very simple, this is the width of the buttocks of the horse. The story should be over, but it is not yet finished.
Next time you see the male space plane on TV, you pay attention, there are two rocket propellauses on both of its fuel tanks, which are set in Utah which provided. If possible, the engineer of this factory hopes to make these propellers will be more fat, so that the capacity will be large, but they can't, why? Because these pushers are made, they should be shipped from the factory from the factory to the launch point. On the road, they must pass some tunnels, and the width of these tunnels is only a little bit better than the width of the train track. The story is quite interesting. In a certain sense, today's most advanced transportation system is designed, perhaps determined by the butt width of two thousand years ago. How strong the power of historical inertia is, how difficult it is to break through the rules formed by inertia. Good habits will not only affect your life, your descendants, grandson, will benefit.
