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Cherenkov radiation acts as an optical sonic boom for high speed charged particles. The figure is taken from US Department of Energy, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Particles moving faster than light in water glow bright blue

Cherenkov radiation acts as an optical sonic boom for high speed charged particles

Although nothing exceeds the speed of light in a vacuum, light travels slower in dense mediums like water, where its speed drops to about 225,000 kilometres per second. When high-energy electrons from a nuclear reactor move through water faster than light travels in that medium, they emit an eerie blue optical shockwave known as Cherenkov radiation.

Where this comes from

US Department of Energy

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Tags: physics, radiation, light

Particles moving faster than light in water glow bright blue: the short answers

Where does this come from, and can I check it?: Cherenkov radiation acts as an optical sonic boom for high speed charged particles. The figure is taken from US Department of Energy, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a science fact?: Yes. It sits on the Science shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.