The blue glow is called Cherenkov radiation, and it's caused by very high energy electrically charged particles, such as electrons, traveling faster than the speed of light in a medium, such as water. Think of it like a sonic boom for light. In certain mediums, the speed of light is slower, and particles can travel faster than light in that medium. For example, the speed of light in water is 225,000,000 metres per second, compared to 299,792,458 metres per second in a vacuum, or about 75% the sp

223K views · 437 reactions | Why do you see a blue glow inside of a reactor? | International Atomic Energy Agency (IAEA) | Facebook

6.1K views · 303 reactions | WATCH  : Why do you see a blue glow inside of a reactor? The International Atomic Energy Agency (IAEA) explains… | U.S. Department of Energy Office of Nuclear Energy | Facebook

Can particles move faster than light? Nobel Prize employee Olof is here to explain more about how that's possible in Cherenkov radiation - the discovery that received the 1958 physics prize Learn more about this effect: https://bit.ly/3X4uIdB Reactor Video Credits: Sandia National Laboratories; IAEA Office of Public Information and Communication | Nobel Prize

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