“When we initially proposed LIGO, the only sources that we were really contemplat…” — Rainer Weiss

We'll have all sorts of crazy signals. And you'd be a damned fool if you didn't look for things you weren't expecting, because that's probably what you're going to see first.

Over and over in the history of astronomy, a new instrument finds things we never expected to see.

The rule has been that when one opens a new channel to the universe, there is usually a surprise in it. Why should the gravitational channel be deprived of this?

The waves from all the different parts of a sphere would cancel each other out. You need motion that's nonspherical.