Astronomers may finally confirm a 90-year-old quantum prediction using a rare magnetar

[Evan0]

Australian astronomers have spotted evidence of a genuinely fascinating quantum effect out in deep space, using a rare ultra magnetic neutron star called a magnetar to hunt for something called vacuum birefringence, a bizarre prediction from quantum electrodynamics that has never been directly confirmed despite being theorized nearly 90 years ago

The basic idea traces back to Heisenberg and colleagues in the 1930s, quantum theory predicts that even seemingly empty vacuum space isnt actually empty at the quantum level, and under an extraordinarily strong magnetic field that vacuum should start behaving like a birefringent material, meaning it polarizes light passing through it differently depending on the lights orientation, similar to how certain crystals split light in everyday optics

Dr Marcus Lower of Swinburne University of Technology explained why this is so hard to actually detect, saying detecting vacuum birefringence requires a magnetic field that is over 100 million times stronger than any weve ever made on Earth, which is exactly why astronomers have to look to genuinely extreme astrophysical objects like magnetars rather than any lab experiment to have a shot at observing this effect at all

Magnetars are an extremely rare class of neutron star with magnetic fields dramatically stronger even than typical pulsars, and this particular target gave researchers a genuine opportunity to look for the telltale polarization signature that vacuum birefringence would produce in light traveling near the stars surface through its intensely magnetized surrounding space

Lower and his team are being appropriately cautious about the result though, theyre specifically working to differentiate the vacuum birefringence signal from other astrophysical processes happening around the magnetar that could produce a similar looking signature, and theyre planning to gather additional data and refine their simulations before calling this a fully confirmed detection

Lower captured the genuine significance of finally nailing this down, saying with these future data on hand and our updated simulations we may finally be able to complete the quest started by Heisenberg nearly 90 years ago, which would be a genuinely satisfying resolution to one of quantum physics oldest still open predictions

Rare Ultra Magnetic Star Keyphys.org

[Mia86]

Using a magnetar as a natural laboratory because no facility on Earth could ever produce a magnetic field 100 million times stronger is such a great example of astrophysics filling in gaps that pure lab physics simply cannot reach

[Diane82]

A prediction from Heisenberg in the 1930s still waiting on direct confirmation nearly 90 years later says a lot about just how extreme the conditions needed to test some quantum predictions actually are, this isnt a quick tabletop experiment kind of physics

[Dom0]

The careful distinction between this signal and other astrophysical processes happening around the magnetar that could look similar is exactly the right level of scientific caution, extraordinary claims in astrophysics need that kind of rigorous ruling out of alternative explanations

[Firewall Stephen]

Rare ultra magnetic stars being the key to testing this kind of fundamental quantum prediction shows how astrophysics and particle physics have become genuinely intertwined disciplines, you cant fully understand either field anymore without drawing on the other

[Niamh88]

This is a nice reminder that some of the most extreme tests of fundamental physics come from astronomical objects rather than particle accelerators or lab experiments, the universe itself provides physical conditions we could never replicate artificially

[ShawnMichaels99]

Vacuum not actually being empty at the quantum level and behaving like an optical material under extreme conditions is one of those genuinely mind bending quantum predictions that sounds like science fiction but is rigorously derived from established quantum electrodynamics

[CodyRhodes29]

Would love to know more about how they actually measure the polarization signature from light coming off a magnetar this far away, the observational technique here seems like it deserves its own explanation given how subtle this effect presumably is

[CrimsonNova71]

Completing a quest started by Heisenberg nearly 90 years ago is such a poetic way to frame this, theres something genuinely satisfying about modern astronomical instruments finally being able to test predictions that were purely theoretical for generations