Whoops sorry I was late reading all my notifications! Yes Alcubierre Drive is the word you're looking for. Or perhaps I think "Alcubierre Metric" probably the better term because it's still just General Relativity.
Ever since GR came out (ie since Townsend Brown was 10) I think it was understood that it meant that you could technically exceed the speed of light by somehow "stretching" space. Basically: Special Relativity in 1905 imposed the speed of light barrier, General Relativity in 1915 didn't exactly remove that barrier, but it hinted that possibly maybe perhaps, if we knew how, we could "warp space" instead to move faster than light. That's what little I understand: that the GR equations do not impose a limit on how fast spacetime can move relative to itself (if "move" is even the right concept) but only on how fast light or matter can move through spacetime. That's quite a big loophole, at least in theory.
Science fiction writers were very quick to seize on this possibility - because interstellar travel without going faster than light is really, really boring, you can only do so many "500 year generation ship collapses into primitive/medieval culture" stories - which is why we got so many variations on "stardrive" or "hyperspace" or "warp" or "wormholes". They all pretty much come down to slightly different twists on the general "vibe" of 1915 GR, though not its numbers.
Generally, sci-fi writers don't have actual mathematical knowledge of GR and want to fudge things to make exciting stories, and the GR people in physics (although it seems like they were invited into the subject by Townsend Brown's friends, eg the Gravity Research Foundation), really aren't interested in trying to build warp drives. The story we've always heard since the 1970s is that "it's theoretically possible to warp spacetime with a machine, but practically impossible, you'd need something the size of a star". Which is why the science interest focused on black holes and not much else.
But Carl Sagan started to cross that boundary with his fictional novel Contact (1985) - he got Kip Thorne, a GR physicist, to construct a somewhat plausible looking "traversable wormhole" solution.
https://en.wikipedia.org/wiki/Contact_(novel)
The Alcubierre metric in GR dates to 1994 according to Wikipedia and I think its main contribution is in reducing the amount of mass/energy required to do the warping. There's still the big problem of needing "exotic matter" or "negative energy" that we don't know how to make and have never observed to exist. With the possible exception of "dark matter", which again we haven't actually seen.
Harold G "Sonny" White is one of the few researchers who seems to be actually poking at Alcubierre Drive type concepts in the lab as opposed to just in mathematical theory. Whether he will actually achieve anything is yet unknown. Most physicists disbelieve that he's onto anything (because the usual numbers given by GR analyses for EM/gravity interaction are just ridiculously tiny).
https://en.wikipedia.org/wiki/Harold_G._White and
https://en.wikipedia.org/wiki/Advanced_ ... Laboratory
It would be very cool if someone did figure out a way of explaining the Biefeld-Brown effect with General Relativity (or even giving us a reliable and undeniable Biefeld-Brown replication rig first, since Lifters didn't seem to be that). I'm still hoping that maybe one of the various "propellantless EM thruster" concepts that are still active at the moment might turn out to give positive results. One such attempt (which seems to be based on a capacitor, but I don't know if it's B-B geometry) called the "IVO Quantum Drive" has been launched into space on a microsatellite in November 2023, but has not yet begun testing.
https://www.reddit.com/r/IsaacArthur/co ... _that_was/
As expected, most science forum posters are extremely skeptical that any of the "EM drives" will ever work, because textbook physics tells us that they can't work. If Townsend Brown was correct that a) a force, motion or masslike effect can be generated electrically and reliably replicated, and b) that it can be distinguished from ordinary electromagnetic effects, and c) that it can be scaled up beyond every replication we know of to date, then textbook physics will need some tweaks.
Oh yeah, there's a strange Korean guy Eue Jin Jeong (
http://dipoleantigravity.blogspot.com/ ) who believes that unmodified General Relativity predicts a "dipole" (ie a linear force/acceleration, a permanent and observer-independent shift in the center of mass) and not just "quadrupole" (sideways wobbling around a center of mass) from a spinning half-sphere. He thinks that this force would naturally produce the jets coming from black holes, and the rings of Saturn, and that this force (the most obvious and the strongest non-Newtonian one to derive from GR) was overlooked somehow by GR mathematicians since Einstein. Well, not overlooked: it's explicitly noticed and deleted because it is believed to be "nonphysical", while everyone focused on the far weaker quadropole effect (eg the waves LIGO believe they have observed, which are so fantastically tiny in theory that they are believed to only possibly be generated by massive objects like black holes colliding).
I don't know if Jeong is at all correct (the entire GR physics establishment rejects him), since I can't "do" GR enough to have any intuition about it. But... I feel like something like "there's a field effect that creates rings around spinning planets" seems possibly sensible. This might simplify a whole bunch of observations, and would probably do a fair number on Dark Matter because "why do galaxies hold together" is the big problem that causes Dark Matter to be invented. However, it would also imply that asymmetric rotating objects (eg half-spheres) would experience an anomalous acceleration along the axis of rotation, increasing with the mass and the speed of rotation, and while there have always been fringe whispers about effects like this, it seems like it ought to be fairly easy to observe and I'm not sure that we do.
IF, and that word is doing a lot of heavy lifting, IF Jeong is correct, then this would be an absolutely massive (pun intended) thing that went wrong right in the foundations of the post-Einstein interpretation of General Relativity and would probably imply that all of cosmology and perhaps the Alcubierre Drive would need to be rethought from scratch. There would maybe also be more powerful interaction effects between electromagnetic and massive objects than current GR theory predicts. And that would be very cool. But again: only if.
Nate