Luca Belluzzi

If you shine a flashlight into thick fog, the light doesn't pass straight through: it bounces off countless droplets and scatters sideways. Light inside a star or in its extended atmosphere behaves much the same way. To understand exactly how it travels, scientists solve radiative transfer equations: it's like mapping out every possible light path in detail.

Light from the Sun is usually unpolarized: its waves oscillate in all directions, like a crowd where everyone waves their arms as they please. But on May 3, 2023, astronomers in Locarno, Switzerland, noticed that during a flare, the light from helium became organized — the waves aligned in one direction, like soldiers on parade.