Scientists May Have Proved a Century-Old Theory That the Vacuum of Space Isn’t Really Empty

Key Points:

• Astrophysicists studied the magnetar 1E 1547.0−5408, which emits strong X-ray and radio waves, to find evidence of vacuum birefringence, a quantum electrodynamic phenomenon predicted 90 years ago.
• Vacuum birefringence occurs when intense magnetic fields cause light polarizations to travel at different speeds in a vacuum, due to the influence of virtual electron–positron pairs predicted by quantum field theory.
• Magnetars have magnetic fields billions of times stronger than Earth's, exceeding the threshold needed to affect light polarization, making them ideal natural laboratories to observe vacuum birefringence.
• Using multiple instruments simultaneously, scientists observed unusually high and stable polarization from the magnetar, supporting the presence of vacuum birefringence in its magnetosphere.
• This discovery, published in Nature, represents a significant step toward understanding quantum vacuum properties and encourages further observational and theoretical research on magnetars.