Meanwhile, around a magnetar in Norma…

NASA’s IXPE May Have Proven 90-Year-Old Theory science.nasa.gov

Point a telescope at a magnetar and empty space itself starts behaving like a lens. After more than 140 hours watching the magnetar 1E 1547-5408, NASA's IXPE found its X-rays polarized in exactly the way quantum theory predicted in the 1930s: in a magnetic field trillions of times Earth's, the vacuum becomes birefringent and splits light. It is the first direct evidence that nothing has optical properties.