Quantum physics has made numerous strange predictions , and scientists have checked and confirmed many of them. But one of the strangest ones persists unresolved. In the 1930s, the German physicists Werner Heisenberg and Hans Heinrich Euler proposed that empty space is not really empty. Instead, they predicted that in the presence of a magnetic field, the vacuum of space would behave like a crystal, changing the properties of light passing through it.
As Sokolova-Lapa and Wilms put it, the high polarisation reported in the study only proves vacuum birefringence if the team’s model of the magnetar’s geometry is correct. The work could prove ‘nothingness’ is actually a complex and active medium and also potentially help scientists refine their maps of the universe. These are staggering numbers far beyond the abilities of current technologies, so physicists have been looking for proof of vacuum birefringence in outer space, where objects called magnetars generate the universe’s most extreme magnetic fields. The models that did not account for the phenomenon fit substantially worse with the telescope data than those that included it. The finding takes a big step towards bolstering space’s character as a complex medium that both gravity and magnetism can manipulate. If, instead, its axis of rotation and magnetic poles are further apart, the X-rays could have been polarised by plasma on the magnetar’s surface. A paper published in The Astrophysical Journal by researchers from Italy, Spain, and the U.K. has already raised doubts about the alignment.
Because the astronomers recorded polarised light and inferred from that that it had passed through extremely magnetised space, the current finding is indirect. In a study published in Nature on August 5, astronomers from Australia, Canada, Japan, South Africa, Taiwan, and the U.S. reported it had observed such birefringence using two satellites and a telescope in Australia, almost confirming the prediction at long last. For vacuum birefringence to become noticeable, the magnetic field has to be around 88 trillion times stronger than the earth’s magnetic field, and more than 500 million times as strong as the ultra-powerful magnets in the world’s largest science experiment, the CERN supercollider.
