# Polarized X-rays from magnetar reveal quantum vacuum effect

Astronomers observed the X-ray polarization from a radio magnetar, providing direct evidence of vacuum birefringence, a quantum electrodynamics effect predicted by QED. The result confirms a key prediction of quantum physics in extreme magnetic fields, offering new insights into high-energy astrophysical processes.

**Importance:** 4/5

## Sources

### Science
- [Nature](https://www.nature.com/articles/s41586-026-10859-z) — 2026-08-05