Why do you see a blue glow inside of a reactor? | International Atomic Energy Agency (IAEA)

What’s that blue glow surrounding a reactor? It’s a phenomenon known as Cherenkov Radiation when electrically charged particles, such as protons or electrons, travel faster than light in a clear medium like water. | U.S. Department of Energy Office of Nuclear Energy

The Cherenkov Telescope Array Observatory (CTAO) is the world’s most powerful ground-based gamma-ray observatory. Built in collaboration with European Southern Observatory (ESO), CTAO is designed to detect the most energetic light in the universe: gamma rays. These gamma rays are released during the most violent cosmic events — exploding stars, supernovae, and extreme particle accelerators in space. Gamma rays travel across the universe at the speed of light. When they reach Earth, they collide