Neutron-star cores contain matter at the highest densities reached in our present-day universe, with as much as two solar masses of matter compressed inside a sphere of 25 km in diameter. These astrophysical objects can indeed be thought of as giant atomic nuclei, with gravity compressing their cores to densities exceeding those of individual protons and neutrons many-fold.

“In a new article published in Nature Communications, a team centered at the University of Helsinki provided a first-ever quantitative estimate for the likelihood of quark-matter cores inside massive neutron stars. They showed that, based on current astrophysical observations, quark matter is almost inevitable in the most massive neutron stars: a quantitative estimate that the team extracted placed the likelihood in the range of 80–90%.”

edit: removed my personal crackpot musings surrounding the subject. I do however, still suggest for those interested on the subject to study/brush up on quantum chromodynamics (focusing on the quark sea) and zero-point energy - never neglecting Relativity, of course. They’re all very much connected and I believe the ZPE field will be a focus of continuous, real experimental science, with significant ramifications in cosmology.

edit 2: Found this research just today on nucleon liquid Vs quark liquid - very interesting and very much related to this original post.