Lines are interesting natural-occurring and man-made phenomena that structure our thinking and provides sensemaking both in the spatial and metaphorical.
A line not only appears on purpose by drawing it or through construction, but also simply through being the contrast or border of two separated parts. Take the horizon. A line that separates air from land. And in an unobstructed view both needs to be present in the field of view for it to appear. Ask a child to draw the horizon and all you will get is a line. There is a lot of beauty in lines, a golden hour horizon is one of the most photographed scenic views, and it is the line that provides this eclipse.