In a paper published in The Astrophysical Journal Letters, the international LIGO-Virgo-KAGRA Collaboration reports on the detection of two gravitational wave events in October and November of 2024 with unusual black hole spins. This observation adds an important new piece to our understanding of the most elusive phenomena in the universe.
“Second-generation” isnt referring to whether it merged before, it’s referring to (and this might be a not fully correct analysis either) whether conservation of angular momentum got fucked up, like when you’re playing Mario Kart and you get smacked so many times that you get confused and start driving in the wrong direction.
It absolutely does mean having merged in the past. That’s why the rotation is different.
That Mario Kart simile may be accurate, but it also got my emotions going in all sorts of directions.