In other words, scientists have found a place in space where matter randomly seems to appear and disappeared over and over again.
For the first time, astronomers have achieved observing a phenomenon in space referred to as Vacuum birefringence using the European Southern Observatory’s (ESO) Very Large Telescope (VLT). Observations may help confirm a theory that dates back 80 years.
Vacuum birefringence was predicted for the first time in the 1930s by physicists Werner Heisenberg and Hans Heinrich Euler as a product of the theory of quantum electrodynamics (QED).
Now, a team of scientists led by Roberto Mignani, from INAF Milan (Italy) and the University of Zielona Gora (Poland), used ESO’s VLT (Very Large Telescope), at the Paranal Observatory (Chile), to observe the neutron star RX J1856.5-3754, about 400 light years from Earth, making a fascinating discovery along the way.
Neutron stars—like the one observed—are very dim, but they are around ten times more massive when compared to our sun. This means they have extremely strong magnetic fields permeating their surface and surroundings.
According to what we have been told in school—and what Einstein and Newton said—vacuums are “empty” spaces where light can pass remaining unchanged.
However, the QED theory states that space is filled with virtual particles that constantly appear and disappear. Now, strong magnetic fields like those found near neutron stars have the ability to modify spaces.
Despite being among the closest neutron stars to Earth, its extreme darkness meant that astronomers could only observe it in visible light utilizing the FORS2 instrument, installed on the VLT, within the limits of current telescope technology.
Vincenzo Testa (INAF, Rome, Italy) comments: “This is the faintest object for which polarization has ever been measured. It required one of the largest and most efficient telescopes in the world, the VLT, and accurate data analysis techniques to enhance the signal from such a faint star.”
By studying the data obtained from their observation, astronomers observed linear polarization occurring at a significant degree of around 16percent—most likely due to vacuum birefringence in space surrounding RX J1856.5-375.
“The high linear polarization that we have measured with the VLT cannot be clearly explained by our models unless the vacuum birefringence effects predicted by QED are included,” explained Roberto Mignani.
“This VLT study is the very first observational support for predictions of these kinds of QED effects arising in extremely strong magnetic fields,” remarks Silvia Zane (UCL/MSSL, UK).
And while these observations are fascinating, Mignani is convinced how future telescopes can help astronomers detect more mysterious quantum effects by studying neutron stars.
“Polarization measurements with future telescopes, such as ESO’s European Extremely Large Telescope, could help astronomers test QED predictions of vacuum birefringence effects around many more neutron stars in the universe,” concluded Mignani.