"Heretics of Science", Professor Eric Laithwaite, and Gyroscopic Propulsion:

On the BBC, there was a series called Heretics of Science. One person featured there was Professor Eric Laithwaite, who is otherwise famous for his work with "mag-lev" trains. We see these in operation in different parts of the world, with trains running off magnetic levitation instead of wheels on rails. Laithwaite was shown a device using gyroscopic precession to drive a small wheeled device. He then went on to present his ideas about this to the scientific community, including what he saw as a reduction in the weight of a gyroscope. He was subsequently shunned and ignored by the scientific community because he dared to challenge what was generally accepted dogma. I recommend finding the episode and any relevant information on Prof. Laithwaite.

He also, during his research, discovered that many many other people had also discovered these effects and there were many attempts to patent versions of it. Since the scientific community refused to accept these discoveries, including claiming that any reductions in weight or apparent propulsion were simply errors in measurement, no actual patent could be issued.

The Biefeld Brown Effect and Torsion Fields:

The Biefeld Brown Effect is claimed by many to simply be ionic wind. It's claimed to be basically the same as ion drives demonstrated in school science fairs. One early model had two charged plates, one larger than the other, that create a conic disruption. When these models were rotated, they showed a much stronger effect than basic ion drives might. The military stepped in and we didn't hear anything else about it in popular magazines.

Gravity is not a "curvature of space". Einstein was trying to explain complex concepts simply and people assumed his simple explanations were exactly how things work. Most are still trying to wrap their heads around how something can curve in all directions in 3D at the same time. Gravity is actually a buoyancy effect. Physical objects create a thinning effect in the "fabric of space" and things "float" towards the less dense area.

The Biefeld Brown Effect disrupts this "fabric of space". Spinning the discs works synergistically with the rotation of the Earth and works with the basic concept of "ether dragging", which the scientific community also claims to have disproved. It's that thinning effect between those charged plates that's a key to the "mercury vortex engine".

Mercury Vapor, Electron Cascades, and Fluorescent Lights:

Mercury will turn to vapor when hit with a strong electrical current. That's how the old fluorescent lights work. The vapor would excite the phosphor on the glass and we'd have light.  We had to be careful not to break one or we might have a drop of mercury to try to keep away from curious children and animals. The mercury was great for this because it created an "electron cascade" rather than a simple flow of current through it. The electrons would be knocked loose and knock others loose till you had this electron chaos bouncing around. It's ideal for creating an electromagnetic disturbance.

This is where things get fuzzy for me. I don't have details, but I can guess at it. If you rotate electrically charged mercury vapor, you should get a nice spinning vortex with the "electron cascade" going on and  create enough of a disturbance to get something much stronger than the Biefeld Brown effect using charged plates. Effects like this are sometimes referred to as "torsion fields".

The Philadelphia Experiment and Naked Terminators:

The "urban legend" of the Philadelphia Experiment, which has had 2 movies based on it, is assumed to have used something like this, but not necessarily using the mercury vortex. The story goes that the giant electric welders at the Norfolk Navy base would create an odd blackout effect and they'd occasionally have tools nearby go missing. This led into research about creating dimensional portals and so forth and led to the Philadelphia Experiment. Unfortunately, living things generate a different energy field, and resulted in some of the test subjects in that experiment being stuck inside walls and such. But of course, it's all dismissed as being just an "urban legend".

Special Relativity and Relative Mass:

You might ask, what does a gyro propulsion device have to do with Stargate portals? It has to do with the "thinning" effect. Thin the "fabric of space" too much and you start opening holes and wind up somewhere you might not want to be. But Einstein's Special Theory of Relativity points to something else.

Its said that as an object approaches the speed of light, its relative mass becomes infinite. The standard reasoning uses "potential energy" and all sorts of movement related numbers to explain the increase in relative mass. I believe that as an object moves through space, it thins the "fabric" around it, like the wake of a moving boat or an aircraft breaking the sound barrier.

If "space" can be thinned out, an object within it will have the same amount of matter, but it will have more mass per unit of "space" around it. I'm assuming that an object in a thinned area of "space" would have the same effect as a bigger heavier object in the "normal" amount of "density" we're used to. The actual mass doesn't change. It's the amount of mass relative to the "density" of space.

It's an explanation for why the Big Bang went off and the whole thing didn't collapse in on itself. The amount of matter / energy per unit of "space" was close enough it didn't tear any "black holes". Then as "space" expanded, the ratios changed enough that enough mass in a small space could tear open a "black hole".

And it explains why time passes differently for people moving at high speeds. "Space" is thinner and events don't occur in that area at the same rate as what we see as "normal".

If something's relative mass can affect how Newton's action / reaction laws work, then it could affect a gyroscopic propulsion device.

Gyros in a Torsion Field:

The propulsion effect we've seen so far from gyroscopic propulsion devices is fairly weak. It's not likely to replace helicopters and jets any time soon. But what if the effect could be amplified?

If a gyro propulsion device is run by mechanical gearing, without any electrical devices to be disrupted by an electromagnetic torsion field, then the effect might be enhanced within that field. The gyros would have the same mass, but the thinning of "space" there might cause them to act as if they were much more massive.

The normally weak effect would be amplified by putting it into a thinned pocket of space.