We know now that probably every galaxy in the universe,
most of them have big super
massive black holes
 that are measured in tens of millions of solar masses. 
Again very compact objects considered to be the centers of each galaxy. 
It turns out they radiate gravitational waves and we're able to see those too. 
So there are a number of different ways that we're going to go forward here.
To come back to what we do, even though, like I said, 
we can't build huge interferometers we can build
bigger interferometers. 
So I would say our grand vision is to build an interforometer that's 20 kilometers, 40 kilometers.
And again, that gets you an instrument that's more sensitive.
Our instruments, LIGO instruments, are capable
of looking, I use this term loosely, out to
a few hundred, maybe a billion light years
or two billion light years depending on what class of sources you're, maybe four billion. Right?
They see a small fraction of what we consider to be the universe. 
But if we could build one that's 40 kilometers long, we could actually see out to the entire universe.
We could see every black hole merger
that ever happened that is on the way to us,
so we could learn so much more about the universe.
