Is There a Cosmic Gravitational Background?

We have our galaxy as a gravitational wave observatory. We're in to a whole episode on this, because it's super awesume. But very briefly, if you look at pole sars out there in the universe, these are fast rotating neutron stars that send us super, super pulses of light and we can tell if those things get pushed away from us or pulled towards us when a gravitational wave passes. And there's an experiment that's looked at some of these very regular pulses, is called nano grave, and they see a signal which looks like cosmic gravitational background radiation. It's early days, and there've been false claims before, so nobody's really accepted this yet. If