Yes, in my 5min review it came up very quickly that “distance” and “light years” have limited uses in astrophysics. In the abstract, they reference the “z” var

Yes, in my 5min review it came up very quickly that “distance” and “light years” have limited uses in astrophysics. In the abstract, they reference the “z” variable of redshift in light (that has traveled for billions of years during which cosmic expansion continued and expanded the original distance) and kiloparsecs (referring to the much closer span of Milky Way through which the emissions traveled, from which they are drawing inferences about dust density therein). Wild, cool stuff!