Chapter 1: Section 7: Page 63: Line 133 (1115)

 Somehow this escalated into a general free-for-all, in which furniture and glassware didn't come out much better than the human participants, a rare sort of behavior among Ætherists, but everybody had been feeling at loose ends lately.

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Being Pynchon, I'm surprised the eruption of a barroom brawl was handled so succinctly. I expected a tray of cream pies to have been rolled into the room just as somebody emptied a bin of banana peels onto the floor. Pynchon's never above a popular trope that modern audiences can easily recognize to regain their attention after wading through paragraphs of high-falutin' philosophical and scientific talk.

Here, we have rational, scientific-minded thinkers breaking into complete and utter violence. It could be commentary on how scientific disputes aren't usually as logical as we common people might think. Passions can erupt when some super smart ass jerk comes along and changes the whole rules of the game so eloquently that it can't be denied. What else can you do but bust them over the head with a whisky bottle?

This could also be one of Thomas Pynchon scant allusions to nuclear proliferation. I wouldn't bet on it but it could be there if you remember how Gravity's Rainbow was all about technology screwing over the masses so eloquently that they could be killed by it before they even knew they were in danger and yet the novel has exactly one scant mention of the atomic bomb. Just a mostly obliterated headling about Hiroshima being bombed. Mostly it's about how plastics got us here and not nuclear fission! That took place during World War II so this bit of Against the Day taking place in the late 19th Century, maybe the only way to allude to nuclear bombs is a barroom brawl between science-minded philosophers and the use of the word "escalated".

"everybody had been feeling at loose ends lately"
Here we return to the idea of loss of faith or, in general, simply loss itself. The peak elation of the people who gathered in Cleveland for the experiment that would prove the existence of Æther has dropped beyond the zero to the trough of disappointment. What they had come for had not been delivered and now they don't know what to do. The end of the world, so to speak, did not come about and now they had to pick up the pieces and find a new path. Loose ends. Feeling lost. A foundational belief about the way the universe worked has been destroyed. Here in the late 19th Century, these cracks and failing are beginning to happen more and more rapidly. Æther has just crashed out and burned. The Frontier's waning. Imperialism is turning back in on itself as the nationals of oppressed nations emigrate to their oppressor's homelands.
    Modern readers in the 21st Century can easily identify with the rapid collapse of seemingly foundational institutions. Feeling at loose ends no longer qualifies as a brief disruption in a long stretch of stability; it has become the stability itself.