New method may resolve difficulty in measuring universe's expansion

Astronomers using National Science Foundation (NSF) radio telescopes have demonstrated how a combination of gravitational-wave and radio observations, along with theoretical modeling, can turn the mergers of pairs of neutron stars into a "cosmic ruler" capable of measuring the expansion of the Universe and resolving an outstanding question over its rate.

source https://www.lifetechnology.com/blogs/life-technology-news-blog/new-method-may-resolve-difficulty-in-measuring-universes-expansion