How did humans create all the straight things in the world?

Question

lets take for example a straight edge. I know it came from the factories. but how did we humans invent things that make watever we want flat and straight?

Answer 1

Many objects fracture in flat faces (such as some rocks), and by laying molten metal in a mold the metal at the mold's top will always lay out flat just like water on a lake, as well as other methods.  It evolved from there, one relatively straight tool making a straighter tool and so on (like using computers to make better computers).

But remember, there can never be a perfectly straight line made of particles; even atoms aligned into a "straight" line are not straight because they are so active.  Even light vibrates at a wavelength, and is thus not perfectly straight.  The only way to have a straight line is by way of theoretical numbers (e.g. a linear graph), or by way of creating an imaginary line between two particles.  Since this line is imaginary you can imagine it being perfect, but remember it is not real.

Answer 2

Straight lines were drawn with ropes, strings and alignment of two sticks.

The reason:  people are lazy, and it is less tiring to travel in straight line than to zigzag.

Answer 3

In the really old days, people who lived near bodies of water with long expanses saw a horizon.

The horizon looked straight so straight lines were derived from that.

Those people that lived more inland with less water observed how trees and plants grew. usually straight and upward. Straight lines were derived from those objects too.

Making something straight was appealing to the eye with clean lines.