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In theoretical physics , a kugelblitz (German: "ball lightning", not to be confused with ball lightning ) is a concentration of light so intense that it forms an event horizon and becomes self-trapped: according to general relativity , if enough radiation is aimed into a region, the concentration of energy can warp spacetime enough for the region to become a black hole (although this would be a black hole whose original mass-energy had been in the form of radiant energy rather than matter).
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Mr. Tompkins in Wonderland where c = 10 km/hr