Scientists may have finally caught empty space altering light, a quantum effect predicted by Werner Heisenberg nearly 90 years ago. Observations of a magnetar, a rare neutron star with an astonishingly powerful magnetic field, show signs that supposedly empty space is changing how light travels. This could be the first evidence of vacuum birefringence, a phenomenon that has eluded researchers for decades.
A cosmic laboratory stronger than any on Earth
The effect, known as vacuum birefringence, arises from the idea that even a perfect vacuum is not truly empty. It should contain virtual particles that briefly pop in and out of existence. When exposed to an extraordinarily strong magnetic field, these particles can affect how light moves. The problem is that the magnetic field needed to make this effect detectable is over 100 million times stronger than anything scientists can generate in laboratories on Earth.
Magnetars provide a natural solution. These are neutron stars with some of the strongest magnetic fields known in the Universe. Dr. Marcus Lower, an Australian Research Council DECRA Fellow at Swinburne University of Technology in Australia, helped lead the observations. He noted that nature has provided magnetars as perfect cosmic laboratories to search for this effect.
Watching an extreme magnetar
Lower led observations of the magnetar 1E 1547.0-5408 using CSIRO's Murriyang radio telescope, also known as Parkes. The data were analyzed with Swinburne University's Ngarrgu Tindebeek supercomputer. The team combined these with measurements from NASA's Imaging X-ray Polarimetry Explorer and the NICER X-ray telescope aboard the International Space Station.
Rachael E. Stewart, a graduate student of physics at George Washington University, led the study, which was published in Nature. The research involved scientists from the Center for Space Sciences and Technology, the South African Radio Astronomy Observatory, Los Alamos National Laboratory, NASA's Marshall Space Flight Center, and universities around the world.
The findings could open new ways to investigate quantum physics under conditions that cannot be reproduced on Earth. For decades, scientists have not been able to conclusively confirm vacuum birefringence despite major advances in nuclear physics and particle accelerators. Now, observations of one of the most extreme objects in the Universe may provide the evidence researchers have been seeking.
