Apparently, the Department of Defense is researching the possibility of developing the next generation of incredibly-high-yield explosives. The new bomb emits gamma rays but only requires a tiny amount of the element “hafnium”, which means one could derive a nuclear-size boom from a very tiny bomb. There’s a story in the New Scientist about it:

The hafnium explosive could be extremely powerful. One gram of fully charged hafnium isomer could store more energy than 50 kilograms of TNT. Miniature missiles could be made with warheads that are far more powerful than existing conventional weapons, giving massively enhanced firepower to the armed forces using them.

The effect of a nuclear-isomer explosion would be to release high-energy gamma rays capable of killing any living thing in the immediate area. It would cause little fallout compared to a fission explosion, but any undetonated isomer would be dispersed as small radioactive particles, making it a somewhat “dirty” bomb. This material could cause long-term health problems for anybody who breathed it in.

(Thanks to Rachel for this one!)