I'm not an expert, but as far as I understand it the universe expanding means space itself is stretching at every point. Meaning if something was 1ly away in th

I'm not an expert, but as far as I understand it the universe expanding means space itself is stretching at every point. Meaning if something was 1ly away in the past, it might be farther away due to that effect. This also applies to gravitational waves and anything else inside the universe.