Why do you do science? In this particular case, we don't have a very good reason to be doing this except for the knowledge that it brings. This research is especially important to young people. We all want to know what's going on in the universe.

Space is much stiffer than you imagine; it's stiffer than a gigantic piece of iron. That's why it's taken so damned long to detect gravitational waves: to deform space takes an enormous amount of energy, and there are only so many things that have enough.