I WAS AT a party in downtown Oakland when I first heard about the Voice of
God. It was the usual mix鈥攁 few intellectuals from Berkeley and Stanford,
the gracious host and hostess and a gaggle of greedy journalists, of whom I was
one. The conversation was highbrow and stilted but the food was plentiful, so I
stayed to chat. It was an innocuous, forgettable evening, except for one thing,
a short conversation with an expert in laser optics from Stanford University.
His extraordinary tale left me spinning.
It involved a clandestine military project with a goal so outrageous that,
even now, it is difficult to comprehend. The story was set in the late 1980s, at
an undisclosed military research facility hidden in the New Mexico desert. Here,
researchers working with high-power laser weapons discovered that they could
create a glowing ball of fire in the sky by crossing the beams of two powerful
infrared lasers. The beams were invisible to the naked eye, but where they
intersected, their electric fields became so intense that they ripped apart
molecules in the air, creating a plasma鈥攁 luminous mix of high-energy ions
and electrons.
By moving the laser beams around the sky, the researchers found they could
shift the plasma ball back and forth at very high speed. They even discovered
that by switching the beams on and off quickly and redirecting them to different
spots, they could maintain several plasma balls in the air at the same time. At
night, they demonstrated their skills, flying their glowing creations in
formation high above the cold desert.
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These shows were noisy events. When the intense electric field rips one
molecule apart, it releases electrons that smash into its neighbours, breaking
them apart and releasing more electrons. This develops into a cascade known as
inverse bremsstrahlung, and the result is explosive. Literally. The pressure
wave it creates can reach thousands of atmospheres. Even the smallest shock
waves sound like firecrackers, and by rapidly pulsing the plasma balls on and
off, the researchers created a stream of shock waves that merged together to
form a continuous loud hiss or, depending on the frequency of the pulsation, a
crackle.
Now the tale gets more interesting. According to my fellow party guest, the
team discovered that by modulating the frequency and intensity of the hissing
sound, they could create a voice-like effect. The result was a highly
manoeuvrable, glowing ball of plasma that seemed to appear out of thin
air鈥攁 ball of plasma that could 鈥渢alk鈥�. The US military named the
technology the Voice of God and classified it top secret. My contact said that
he had heard of plans to use the device as a psychological weapon during the
Gulf War in 1991, but that for some reason these plans were never realised.
And there the tale ends. After the party, I contacted the researcher for more
details but he was unable, or possibly unwilling, to provide them. I was stuck
with nothing to follow up鈥攏o military facility, no contact numbers, no
names. Nothing but the idea itself.
So is it possible? Does the technology really exist to create glowing balls
of plasma that talk? Thus began a quest to discover not whether the Voice of God
exists, but whether it could exist.
My first useful interview was with Leik Myrabo, a professor of engineering
physics from Rensselaer Polytechnic Institute in New York state who works with
the Propulsion Directorate at the US Air Force Research Lab at Edwards Air Force
Base in California. Myrabo is no stranger to the way lasers can break down the
atmosphere to form a plasma. He uses the effect to propel prototype spacecraft
into the air on the tip of a laser beam (快猫短视频, 10 January
1998, p 34). But after hearing my story, he sounded sceptical: 鈥淚鈥檓 not saying
it鈥檚 impossible, but it would be difficult.鈥�
The first problem, he told me, would be generating the required intensity of
several gigawatts per square centimetre. The laser Myrabo uses is the most
powerful of its kind in the US. Known as the Pulsed Laser Vulnerability Test
System (PLVTS), it generates a rapid series of infrared pulses, each one lasting
only 18 microseconds. One pulse has the energy of 450 joules. And the PLVTS can
generate 20 of them every second. This gives an average power of 9 kilowatts but
the only way that Myrabo can create inverse bremsstrahlung is by focusing this
beam down to a point. In this tiny spot, the power density is millions of times
higher than in the unfocused beam, and the air explodes. 鈥淚t sounds like a
firecracker going off,鈥� he said.
The focusing optics in Myrabo鈥檚 propulsion system are built into his
prototype spacecraft: the back of the craft is a curved mirror. But the Voice of
God would not have the benefit of a curved mirror or a lens floating in the air,
and any focusing system built at the laser end of things would have to be huge
to operate over long distances. There鈥檚 another problem: crossing two laser
beams would be of little value, according to Don Walters, an atmospheric
physicist at the Naval Postgraduate School in Monterey, California. 鈥淐rossing
the beams only doubles the intensity but you鈥檇 need to increase it by many
orders of magnitude,鈥� he said.
Without the ability to focus the beams, Walters and Myrabo agree that Voice
of God technology would require lasers vastly more powerful than any that are
easily available today. 鈥淚 suppose NOVA could do it,鈥� Walters told me, referring
to the world鈥檚 most powerful laser at the Lawrence Livermore National Laboratory
near San Francisco. 鈥淏ut that鈥檚 the size of an entire building.鈥�
But Walters didn鈥檛 dismiss the idea outright. 鈥淚t seems a bit far-fetched,
but I suspect it could work in the lab with just one laser,鈥� he said. In fact,
he went as far as to say that creating a laser-induced plasma should be easy in
many labs but that the plasmas can only be produced a few centimetres in front
of the lenses that focus the beam.
Controlling the frequency of the pulses would be straightforward too, though
changing their intensity would be tough. 鈥淏ut I wouldn鈥檛 be surprised if
somebody had already done it,鈥� he said. After many telephone calls and several
interviews, the consensus seemed to be that the Voice of God was possible in the
lab but very difficult to produce in the sky.
Finally, I contacted John Pike, a spokesperson for the Federation of American
快猫短视频s in Washington DC and a long-time observer of the US military machine.
鈥淚鈥檝e never heard of it,鈥� he said, pointing out that it sounded a bit like a
story that had circulated soon after the Gulf War. Somebody, he said, had
suggested beaming a short film of an imitation Allah saying 鈥淕o home鈥� onto the
low clouds over Kuwait, but apparently the plan was never put into action.
So what about the Voice of God? Pike wasn鈥檛 particularly impressed with the
idea. 鈥淚t sounds like a project that didn鈥檛 have the benefit of adult
supervision,鈥� he joked. Conceivably true, I thought, but hardly grounds to rule
out the possibility. After all, the US military has tested a piloted flying
saucer, experimented with mind control, and attempted to recreate Star
Wars technology in space. Would the Voice of God really be a step too
far?
Given the way the extraordinary keeps becoming ordinary, I doubt it. And even
if the idea hasn鈥檛 been tried before, somebody is almost certain to try it now .
. .