Puxun Wu

The Universe arranged a race of light beams. Fast radio bursts from distant galaxies made it possible to test: if the photon had mass, blue light would arrive later than red. In reality, the delay is explained only by gas. New mass limit: 5×10⁻⁵¹ kg – light is practically weightless.

Scientists described how magnetic fields in the early universe, like an invisible spoon, stirred spacetime, creating eddies that condensed into black holes. These holes could be a major component of dark matter.