Corona discharge Corona discharge A corona discharge is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged. Spontaneous corona discharges occur naturally in high-voltage systems unless care is taken to limit the electric field strength. A corona will occur when the strength of the electric field (potential gradient) around a conductor is high enough to form a conductive region, but not high enough to cause electrical breakdown or arcing to nearby objects. It is often seen as a bluish (or other color) glow in the air adjacent to pointed metal
Mum's the word Mum's the word Mum's the word is a popular English idiom. It is related to an expression used by William Shakespeare, in "Henry VI, Part 2". The word “mum” is a slanged version of momme, which was used between 1350-1400 in Middle English with very close to the same meaning: Be silent; Do not reveal "Mum's the word" means to keep silent or quiet. "Mum" is a Middle English word meaning 'silent', and may be derived from the "mummer" who acts without speaking. Note the similar English word "mime" (Old English "mīma", Latin "mimus") meaning silent actor or imitator. The