how were straight lines made?
in elementary school, my teachers would say, “if you need a straight line use a ruler,” but how did they get a ruler to be straight? it must have come from a machine or something, but how did people get the first one?
one way I’m imagining it is if you stretch out a string taut you can get a straight line, but how was this applied to everything else that uses straight lines?
is there something in nature that is perfectly straight?