Re: [groff] Spooky action at a distance in line adjustment...sometimes

[Doug McIlroy]

Ancient history: when I wrote BCPL roff, I immediately noticed the
page-level density gradient from thick on the left to thin on the
right if padding spaces were inserted from the right. I next tried
randomly distributing the padding. This was even worse because it
led one to perceive false phrase boundaries at the wider spaces.
The text became maddening to read. Only then did I try alternating
left- and right-padding, which has stood the test of time.

But all this is a frill. Justified text seemed like a nice idea
at the time, because it distinguished computer-composed documents
from old-fashioned typewritten documents. But it soon became old
hat and people migrated back to ragged right margins, which may
not look as neat from afar, but also seem to be easier to read
both because of even spacing and because the variable margin 
provides distinguishablility to help a reader track vertical
position on the page.

Doug