NOW FOR SOME MORE SCIENCE-FICTION REALITY

Remember the mysterious black barge anchored in the Hudson River between the Manhattan and Jersey shores during our Code Orange New Year eight months ago? Well, the barge is back. Make that two of them. And just in time for the National Republican Convention at Madison Square Garden, which will be protected by "the largest armada of land, air and maritime forces ever assembled to provide security at a national political gathering."

Our Upper West Side spotter, who checked the barges out yesterday with her binoculars, wonders whether they're platforms for guided-missile launchers to protect the city from an airborne attack. The last time they appeared in the river we never did solve the barge mystery. This morning's report on convention security in The New York Times makes no mention of missile launchers stationed in the Hudson. It does say that 26 police launches will patrol the city's waterways and that seven surveillance helicopters will be patrolling the skies.

I guess we should also mention the 181 bomb-sniffing dogs to be put on the streets and subways, in additon to plainclothes detectives who will "eyeball" other riders, along with 10,000 police officers to be stationed around Madison Square Garden itself, including "special heavily armed 'Hercules' antiterror squads, snipers and phalanxes of officers set up around the arena to search buses and trucks."

And let's not forget: The police will have on hand a bit of high-tech sonic weaponry just in case noisy demonstrators need to be brought into line. As reported by the Associated Press, it was unveiled last week as part of  "a mini-arsenal of devices and counterterrorism equipment." Called the LRAD (for Long Range Acoustic Device), the weapon was "developed for the military and [is] capable of blasting warnings, orders or anything else at an ear-splitting 150 decibels."

The police plan to mount two LRADS on Humvees posted outside the arena. "It would mark the first time the instrument -- which can beam sounds for 300 yards or more -- has been used by a civilian force." This does not go down well with Bill Dobbs of United for Peace and Justice, which has planned a massive antiwar demonstration on the eve of the convention. He called the sound system "a potential Big Brother nightmare." Police "are trying to use technology and machinery to control every aspect of life on the street," he said, "rather than relax a little and let a part of democratic society unfold."

Compared with infrasound, however, the LRAD is a light tap on the shoulder. Imagine the authorities getting hold of one of French robotics scientist Vladimir Gavreau's "police whistle," sometimes called a "sound cannon." It's an infrasonic device so lethal there is reportedly no known defense against it. By lowering the frequency of sound below 15 cycles per second -- so low that the sound can't be humanly heard -- such a device is capable of spreading death and destruction from a source that is impossible to detect without special equipment.

"At a very specific pitch, infrasound explodes matter," Gerry Vassilatos writes about Gavreau's experiments from the 1930s to the 1970s. "At others, infrasound incapacitates and kills. Organisms rupture in its blast."

Years ago, as far back as the 1960s, the author William S. Burroughs wrote about using sound as a weapon. In a wide-ranging 1984 interview, he noted: "It is no exaggeration to say that all important research is now top secret, until someone lets a rat out of the bag. Infrasound, for example." How does infrasound work? Burroughs explained in layman's terms:

As everyone knows, sound is a succession of waves in which the air is alternatively compressed and decompressed. Fast vibrations either go right through solid objects or bounce off them, usually doing relatively little harm even when very powerful. But slow vibration, below the hearing level, can create a sort of pendulum action, a reverberation in solid objects that quickly builds up to intolerable intensity.

To study this phenomenon the [Gavreau] team built a giant whistle, hooked to a compressed air hose. Then they turned on the air. Professor Gavreau says: "Luckily, we were able to turn it off quickly. All of us were sick for hours. Everything in us was vibrating: stomach, heart, lungs. All the people in the other laboratories were sick too. They were very angry with us."

Gavreau discovered that the wave length "most dangerous to human life" is 7 Hertz (seven cycles per second). Some of the invisible injuries to Gavreau and his team were more persistent. According to another account, they "were dangerously ill for days, their internal organs wracked with painful spasms as a result of their body cavities having resonated at the deadly frequency." They had only just escaped being "torn apart" by their own experiment. What's more, "the entire test building was shaken and nearly destroyed."

Claims like that are hard to believe. But others go further. In one test, reportedly "involving a device less than a cubic metre in volume," Gavreau's team "caused a large, fan-shaped portion of Marseilles to shake. Later, a mounted and remotely controlled version [of the device] was said to have 'burst heavy battlements and tank interiors open with a hideous effortlessness.'"

And Burroughs notes:

In developing a military weapon, scientists intend to revert to a policeman's whistle form, perhaps as big as eighteen feet across, mount it on a truck and blow it with a fan turned by a small airplane engine. This weapon, they say, will give forth an all-destroying 10,000 acoustic watts. It could kill a man five miles away. There is one snag: at present, the machine is as dangerous to its operators as to the enemy.

That wouldn't deter suicide infrasounders. But we're grateful for the snag. In any case, he was talking about the situation in 1984. What has been developed since? For a more recent, extended essay on infrasound weaponry, see "Sonic Doom," an article by Jack Sergeant and David Sutton in the Fortean Times. They debunk the effectiveness of such weapons.

Although Vassilatos writes that "infrasound does not lose its intensity when travelling very long distances across the ground" and remains "at the same intensity as when released," Sergeant and Sutton contradict him. They write:

The main difficulty lies in propagating the sound waves over distance to their intended target, a possibility hampered by the tendency of low-frequency waves to expand in all directions, thus losing focused power, and of high-frequency waves to enter a "shocked state" where energy is lost to the air.

So sonic weapons, even those employing ultrasound and infrasound, would only work over very short distances and, rather than resulting in the kinds of psychological or physical effects claimed by conspiracy-heads or military nuts, would probably just cause serious and permanent hearing damage.

Their conclusion? "Sonic weapons, despite the oft-repeated claims, would most likely be large, cumbersome, close-range devices resulting in ruptured eardrums." Who is correct? Whom to believe? We don't know. But we'd hate like hell to find out at the National Republican Convention.