I found something really cool in a book that I saw in a library, namely that there exist something like a train schedule diagram. Which is exactly a spacetime diagram but then for a simple real world application. It has the distance on y-axis and the time on the x-axis like so:
So actually I just found out after posting this blog that Numberphile just did a video about this, that’s a coincidence:
A writing place. 
Very cool! How could you possibly take this analogy further though? Perhaps assuming all of them move at the same speed (light) we can construct a metric on the space and then a possible mass distribution? Idk if there is anything fun to play with here but maybe?
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Hello Akaashl thanks for your comment! 🙂
Maybe it would work if all the trains go the same speed yes. But then they act like light and you can’t board the trains anymore ;). Because there is no reference frame of light, right.
Well if you suppose there is something that acts like the invariant speed of light you will get a one to one analogy. I don’t really know what kind of thing would make that natural for trains and train stations. Maybe another assumption would be that a train cannot arrive somewhere before their departure for any observer, I think technically you also then have a one to one correspondence.
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