Fighting with photons

The most famous weapon of science fiction is rapidly becoming fact

The deployed ray gun (or “directed-energy weapon”, in the tedious jargon that military men seem compelled to use to describe technology) is known as Zeus. It is not designed to kill. Rather, its purpose is to allow you to remain at a safe distance when you detonate unexploded ordnance, such as the homemade roadside bombs that plague foreign troops in Iraq.

If Zeus works, it will make soldiers’ lives noticeably safer. But what would really make a difference would be the ability to destroy incoming artillery rounds. The Laser Area Defence System, LADS, being developed by Raytheon, is intended to do just that—blowing incoming shells and small rockets apart with laser beams. The targets are tracked by radar and (if they are rockets) by infrared sensors. When they come within range, they are zapped.