straight line is the shortest path between two virtual points.
Context can play a key role in interpreting a line. Müller-Lyer's
illusion, due to German sociologist Franz Carl Müller-Lyer
(1857-1916), proves that a segment can visually appear longer
or shorter if it is framed between two angle brackets the points
of which are directed either outwardly or inwardly, as illustrated
in fig. 1 below.
happens if we do add motion to the illusion? As shown on the
animated gif, the central red dot is equidistant from the other
two red dots, although the ends of the line visually appear
to alternately stretch and shrink like a rubber band!
the sequence of the 26 basic frames of the animated gif, it
would also be possible to create an amusing flipbook!
an hypnotic radial pulsating variant. Though the star seems
to pulsate the blue and black segments are always the same length.