LIGO is a huge milestone. Turning it on is like the moment Galileo pointed his telescope to the moon. This is a new class of instruments observing the universe in a medium that was never utilized before. Using gravitational waves can observe things that cannot be seen before, like stars behind the dust clouds.

It opens a new window to the world. We might finally be able to “see” dark matter. May be able to see the gravitational imprint from before the Big Bang, the gravitational leak from extra dimension or other universes.