Kenneth Chang

Ya know, the parenthetical about him dying in 1712 does that too.

That just retracts the literal statement that he observed through 1713, like my "Cassini and his friends stayed at the party until midnight (Cassini went home at 8 and promptly died)" example.

In this context, I think it's clear that the "others" were not huddled around Cassini and his telescope in 1665 and during every other observation. Thus, it's not essential that Cassini be present at every one, either. English isn't always precise.

allows Bob and Tim to miss Lakers games, but it's false if Bob actually left the Lakers in 2003 or died. (2/2)

If Cassini is not required to be at all observations, why is he required to be at the last one? If he hadn’t died, would this still bother you? He’s sleeping! Resting! Stunned!

Well, suppose that I said "Cassini and his wife ran in the Boston Marathon until 2018." That's not inconsistent with missing a marathon in 2006, but if Cassini *stopped* running marathons in 2008 or even 2017 it wouldn't be true.

“Cassini and others broke time records in the Boston Marathon each year until 1983. (Cassini retired in 1982.)”

I think that's self-contradictory. My basic position is that "and others" does not in any way change the meaning of the sentence as to Cassini, though "successor" would imply a substitution.