Palmer on her interactions with technologists/tech workers:
“These are people who are obsessed with maximizing their impact on the world, she says, but who aren't sure they're going about it the right way. They ask her how they can foresee the repercussions of the things they will do. 'How would the inventors of glitter have imagined that they would poison manatees?' she asked. 'You feel this kind of paralysis.'”
The waves are produced by mass accelerating through spacetime, so in theory everything produces them—you, me, a black hole, a neutron star. As physicists learn to tune their instruments, more sources of the waves will be within reach. But you're right: the odds of detecting a signal this strong and clear right off the bat were low. If LIGO hadn't happened to be on when the waves reached it, after 1.3 billion years of traveling through the cosmos, they would've been missed completely. So this was a mix of extraordinary science and extraordinary good luck.
As the end of the article discusses, this means that scientists have a whole new way of observing the universe. What we saw before was mostly along the EM spectrum—radio waves, visible light, etc. This is a way of looking at distortions in the actual fabric of spacetime.
Hard to say what the practical applications will be, but it's akin to asking Galileo what the practical applications of a telescope are. There probably aren't any if you're a 17th-century merchant or something, but a few decades down the line…
“These are people who are obsessed with maximizing their impact on the world, she says, but who aren't sure they're going about it the right way. They ask her how they can foresee the repercussions of the things they will do. 'How would the inventors of glitter have imagined that they would poison manatees?' she asked. 'You feel this kind of paralysis.'”