In relation to Neutron Stars in the 1 March 1997 session, this has been published today in ScienceMagazine: Astronomers spot signs of weird quantum distortion in space _http://www.sciencemag.org/news/2016/11/astronomers-spot-signs-weird-quantum-distortion-space?
It still is not definitive but interesting and timely nevertheless.
Since the invention of quantum theory in the 1920s, physicists have known that the vacuum of empty space is not a sterile, static thing. Thanks to quantum uncertainty, the vacuum roils with particle-antiparticle pairs that pop in and out of existence too quickly to be seen. Although these virtual particles cannot be captured directly, they can affect the properties of the vacuum. For example, by interacting with those pairs a strong electric field can change the vacuum and, hence, the inner workings of atoms.
In the 1930s physicists realized that a very strong magnetic field would affect the virtual particles in the vacuum and make light travel at different speeds depending on the direction of polarizations. The two-speed effect is known as birefringence and it is used in many optical devices. It gives the crystal calcite its famous ability to produce double images of objects. But the effect arises through quantum effects. In the vacuum, the virtual particle pairs can move more easily along the magnetic field than perpendicular to it, Heyl explains. So light polarized along the magnetic field interacts more strongly with the virtual particles and is slowed ever so slightly compared with light polarized perpendicular to the field, Heyl says.
It still is not definitive but interesting and timely nevertheless.