These lines and shapes that Gottlieb used were easily interpreted to mean different things by different people.

The midsternal line can be interpreted as a segment of the median plane.

The line was widely interpreted as a reference to himself, too.

This blue line labelled ct may be interpreted as the time axis for the second observer.

Alternatively, lines starting with a sign are interpreted as Ruby as well:

But Steve now realized the lines could be interpreted in a completely different way.

Those lines have been interpreted as a claim to reestablish the birthright of the Estonian language.

Other lines are interpreted as the solstice and equinox curves.

More specifically, the line integral over a scalar field can be interpreted as the area under the field carved out by a particular curve.

These lines are now interpreted as points in the projective plane.