I just think that if there were a wave detector the size of a galaxy I'd have probably seen it by now, right?
People aren't on Hacker News for the jokes, and a significant fraction don't like seeing threads hijacked by silliness. We've all seen Reddit, and are choosing not to be there for a reason.
That's not to say that you can't get away with jokes here. But the bar for them to work is very high.