‘Telepathic ray guns’ that beam voices into the target’s skull. Weapons to disrupt balance or cause artificial fevers. Devices to trigger epileptic-type seizures from afar. Those are just a few of the exotic items described in a 1998 Army document, describing the "Bioeffects Of Selected Nonlethal Weapons." I give my take in this week’s New Scientist.

The document is a run-down of the state-of-the-art at the time of the different directed energy technologies (laser, microwaves and acoustics) that might be developed into effective nonlethal weapons.

It took a few weeks get the article out –- Sharon descibed it in Danger Room earlier — because my editors wanted to confirm that the document was for real. It looks as though it was released under the Freedom Of Information Act – but how could we be sure? Under other circumstances there might not be any issue, but in the area of directed-energy nonlethals there are a lot of wild claims.

Because the frequency of the sound heard is dependent on the pulse characteristics of the RF energy, it seems possible that this technology could be developed to the point where words could be transmitted to be heard like the spoken word, except that it could only be heard within a person’s head.

In one experiment, communication of the words from one to ten using "speech modulated" microwave energy was successfully demonstrated. Microphones next to the person experiencing the voice could not pick up the sound. Additional development of this would open up a wide range of possibilities.

….This technology requires no extrapolation to estimate its usefulness. Microwave energy can be applied at a distance, and the appropriate technology can be adapted from existing radar units. Aiming devices likewise are available but for special circumstances which require extreme specificity, there may be a need for additional development. Extreme directional specificity would be required to transmit a message to a single hostage surrounded by his captors. Signals can be transmitted long distances (hundreds of meters) using current technology. Longer distances and more sophisticated signal types will require more bulky equipment, but it seems possible to transmit some of the signals at closer ranges using man-portable equipment.