O'Neill's dream of vacuuming people off of Earth (was Overpopulation)

That would be the Woodstock concert Rand was refering to.

"At Ford Hall Forum in 1969, Ayn Rand examined the cultural significance of two high-profile,
enormously well-attended but very different events: Woodstock and the Apollo 11 launch.
In her lecture, "Apollo and Dionysus," she showed how philosophical ideas play out in a culture:
she showed why these two events, so opposite in nature, were a product of a long-standing philosophical
dichotomy, reason versus emotion. She concluded her talk by noting that, against the bromide that mans
senses and reason confine him to the grubby, material world while his mystical emotions lift him to the stars,
Woodstock and the Apollo 11 launch "offered you a literal dramatization of the truth: it is mans irrational
emotions that bring him down to the mud; it is mans reason that lifts him to the stars."

When the soiled drunken crowds finally left Woodstock the fields were devastated and covered with trash. When the
crowds that had come to see the Apollo 11 launch left there was nary a piece of trash.