Nuclear Physics at Two Kiloparsecs with Millisecond Pulsars

The central densities of neutron stars are the highest known in the Universe, reaching several times the density of an atomic nucleus.  Measurements which can probe the interiors of radio pulsars, the most common form of neutron stars we know, or even their overall mass and radii, can give us unique insights into the physics of matter at extreme densities.  Improvements in millisecond pulsar timing, using the world's biggest and most sensitive radio telescopes, have recently provided precision measurements of several high-mass pulsars which strongly constrain such physics and indicate that the exotic physics at the centers of neutron stars may not be so exotic after all.