BY JIM WILSON
Photo by Philip Gentry
Ever since electricity was tamed in the 19th century, the
idea of manipulating gravity by altering an
electromagnetic field has been the subject of intriguing
experiments and occasional bursts of irrational exuberance.
Physicists insist that because gravity is a basic force of
nature, constructing an antigravity machine is theoretically
impossible. But recently, and not without some reluctance,
they have begun to consider another possibility. Several
highly respected physicists say it might be possible to
construct a force-field machine that acts on all matter in a
way that is similar to gravity. Strictly speaking,
it wouldn't be an antigravity machine. But by exerting an
attractive or repulsive force on all matter, it would be the
functional equivalent of the impossible machine.
While an operational device is at least five years in the
future, developers of what can be loosely termed a force-field
machine say it has cleared major theoretical hurdles. To
demonstrate their claim, they invited POPULAR MECHANICS to
visit their Huntsville, Ala., laboratory to see the most
important component of their proof-of-concept demonstrator. It
is a 12-in.-dia. high-temperature superconducting disc (HTSD).
When the force-field machine is complete, a bowling ball
placed anywhere above this disc, which resembles a clutch
plate, will stay exactly where you left it.
Everyone knows that gravity is the glue that
keeps our feet on the ground and the planets on their orbits.
It operates on every single molecule and atom in our bodies.
Physicists define gravity as the attractive
force between two masses. They also say it is the weakest and
most pervasive of the four basic forces of nature. The others
are the strong force and weak force that operate within the
atomic nucleus and the electromagnetic force that explains
everything from refrigerator magnets to light bulbs,
telecommunications to chemistry.
Machines that use electromagnetism to defy gravity have a checkered
history. In 1911, Edward S. Farrow, a New York engineer,
staged public demonstrations of a weight-reducing device he
called a condensing dynamo. In all likelihood it was no more
than an electromagnet, a small version of the behemoths that
lift wrecks into junkyard crushers. Earlier this year, BAE
Systems, a major British aerospace company, announced that it
had taken up the gravity quest with an
initiative called Project Greenglow. The mainstream physics
community immediately dropped a load of wet blankets on the
defense contractor, claiming it was wasting money on a bad
The Einstein Connection
Prospects for the Alabama HTSD are attracting serious
attention because this particular disc was fabricated by Ning
Li, one of the world's leading scientists. In the 1980s, Li
predicted that if a time-varying magnetic field were applied
to superconductor ions trapped in a lattice structure, the
ions would absorb enormous amounts of energy. Confined in the
lattice, the ions would begin to rapidly spin, causing each to
create a minuscule gravitational field.
To understand how an HTSD is critical to the construction
of a force-field machine, it's useful to know something about
an unusual state of matter called a Bose-Einstein condensate.
In our day-to-day lives we encounter three states of matter:
solid, liquid and gas. In the laboratory it is possible to
create another state of matter in which all the atoms are
aligned in a way that makes them behave as if they were one
single atom. This novel state of matter is named after Albert
Einstein and Indian physicist Satyendra Nath Bose who
predicted its existence decades ago.
In an HTSD, the tiny gravitational effect of each
individual atom is multiplied by the billions of atoms in the
disc. Using about one kilowatt of electricity, Li says, her
device could potentially produce a force field that would
effectively neutralize gravity above a 1-ft.-dia.
region extending from the surface of the planet to outer
"The first thing to understand about Li's device is that it
is neither an antigravity machine nor a gravitational shield,"
says Jonathan Campbell, a scientist at the NASA Marshall Space
Flight Center who has worked with Li. "It does not modify
gravity, rather it
produces a gravity-like field that may be either attractive or
repulsive." Li describes her device as a method of generating
a never-before-seen force field that acts on matter in a way
that is similar to gravity. Since it may be
either repulsive or attractive she calls it "AC gravity." "It adds to, or
counteracts, or re-directs gravity," explains Larry
Smalley, the former chairman of the University of Alabama at
Huntsville (UAH) physics department. "Basically, you are
adding a couple of vectors to zero it [gravity] out or enhance
Although he didn't call it AC gravity, Einstein's theory
of relativity predicts this effect. All objects produce
gravito-magnetic energy, the amount of force proportional to
its mass and acceleration. Li says that the main reason this
energy has never been detected is that the Earth spins very
slowly and the field's strength decreases rapidly as you move
away from the center of the planet. The first measurements are
expected to be made by NASA's Gravity Probe B experiment,
which is planned for launch in 2002.
Beginning with the most basic law of physics--force = mass
x acceleration--Li reasoned that it would be possible to
perform the same experiment here on Earth, using ions locked
in a lattice structure inside a superconductor. When an ion
rotates around a magnetic field, the mass goes along for the
ride. This, according to Einstein, should produce a
Unlike the planet, ions have a minuscule mass. But also
unlike the Earth, they spin their little hearts out, rotating
more than a quadrillion times a second, compared with the
planet's once-a-day rotation. Li calculates this movement will
compensate for the small mass of the ions.
Li explains that as the ions spin they also create a
gravito-electric field perpendicular to their spin axis. In
nature, this field is unobserved because the ions are randomly
arranged, thus causing their tiny gravito-electric fields to
cancel out one another. In a Bose-Einstein condensate, where
all ions behave as one, something very different occurs.
Li says that if the ions in an HTSD are aligned by a
magnetic field, the gravito-electric fields they create should
also align. Build a large enough disc and the cumulative field
should be measurable. Build a larger disc and the force field
above it should be controllable. "It's a gravity-like force
you can point in any direction," says Campbell. "It could be
used in space to protect the international space station
against impacts by small meteoroids and orbital debris."
Concept To Machine
Although Li's theory has passed through the scientific
quality-control process called peer review and an HTSD has
been constructed, important technical unknowns remain. This
summer, Li left UAH. She and several colleagues are striking
out on their own to commercialize devices based on her theory
and a proprietary HTSD fabrication technique.
Li's next step is to raise the several million dollars
needed to build the induction motor that individually spins
the ions in the HTSD. "It will take at least two years to
simulate the machine on a computer," says Smalley, who plans
to join Li's as-yet-unnamed company after he retires from UAH.
"We want to avoid the situation that occurred in fusion where
extremely expensive reactors were built, turned on, and didn't
work as intended because of unforeseen plasma instabilities."
Li says she has turned down several offers for financial
backing. It is less about money than control. "Investors want
control over the technology," she says. "This is too
important. It should belong to all the American