The atomic bomb dropped on Hiroshima in 1945, known as "Little Boy," contained about 64 kg of uranium-235, but due to the bomb's low efficiency, only around 0.5 grams of that uranium actually underwent nuclear fission. This tiny amount of matter was converted into energy, releasing a blast equivalent to about 15,000 tons of TNT. To put it in perspective, 0.5 grams is roughly the weight of a butterfly—yet it caused one of the most devastating explosions in history. This illustrates the incredible energy potential contained within even a minute amount of mass, as described by Einstein’s equation E=mc².