Answer: Fires

In 2011, a group of researchers at Harvard University demonstrated a rather interesting technology they had developed working on a study funded by the Defense Advanced Researches Project Agency: an electrical wand that extinguishes fire.

The basic principle behind the wand is that when a relatively small amount of electrical energy is discharged directly into it, it generates an oscillating electric field. The oscillating electric field causes the soot particles to become electrically charged and affect the stability of the flames, effectively detaching the fire from the fuel source and putting the fire out.

The technology will hardly replace water hoses for large scale fire fighting, but the scientists behind the development hope to see it incorporated into buildings alongside other fire suppression technologies to help stamp out small home and office fires without the damage caused by water or foam systems.