The Good Ship Further, the starship in the Big Time Space Opera I'm researching, will have FTL and artificial gravity. A few months ago I complained about the difficulties I was having coming to terms with the level of handwaving necessary to get artificial gravity on an interstellar spaceship without having to work out the mathematical complexities of a rotating crew section acclerating at high speeds. This was something that honestly kept me up nights, and seemed to be a brick wall I kept bashing my head against.

And then, this last weekend, I ran headlong into a paradigm shift. I was researching the Zero-Point Field, which I'd already decided would be the basis for power generation on the Further. I'd recently decided, too, that instead of some sort of magic "underspace impellers" the starship would be propelled by something like a bias drive or pitch drive, both proposed by Marc Millis of the late, lamented Breakthrough Physics Propulsion Program. I'd read up a bit on Alcubierre's "warp drive," but couldn't work out how to integrate it.

Then I found the website of the Institute for Advance Studies in Austin. And, more specifically, their report Engineering the Zero-Point Field and Polarizable Vacuum for Interstellar Flight, originally presented in 2001 at the University of Sussex. This one document, probably the best single primer on the relationship between ZPF and gravity that I've found, really opened my eyes, and helped to cast a lot of the material I'd already gathered in a new light. I don't think I've come across this "polarizable vacuum" representation of general relativity before, but it's fascinating. The part which really rings my bell was first proposed by a Russian physicist, Andrei Sakharov, in the late sixties. He proposed that "gravitation is not a fundamental interaction at all, but rather an induced effect brought about by changes in the quantum-fluctuation energy of the vacuum when matter is present."

Cool, huh? Well, I had to read that through a few times before it made it past my forehead. This idea is dependent on a completely different conception of space than that I've been taught. Put as simply as possible (and lensed through my own meager layman's understanding) it states that spacetime isn't curved, as has been the consensus since Einstein, but flat. And that the characteristics of flat space are modulated and modified by the presence of matter.

"In brief, Maxwell's equations in curved space are treated in the isomorphism of a polarizable medium of variable refractive index in flat space; the bending of a light ray near a massive body is modeled as due to an induced spatial variation in the refractive index of the vacuum near the body; the reduction in the velocity of light in a gravitational potential is represented by an effective increase in the refractive index of the vacuum, and so forth. "

So this isn't just a question of gravity, but everything. The speed of light, "effective" mass, clock speeds, energy states, and "rulers"--all are no longer fundamental qualities, but secondary characteristics of the quantum vacuum. And if you were able to jigger the "variable vacuum dielectric constant" (how's that for a mouthful?), you could actually change those metrics. Reduce that constant, and you increase the local speed of light, decrease effective mass, speed clocks and expand rulers. How is that useful? Well, if you increase the speed of light, you get accelerate to arbitrarily fast speeds without violating the restrictions against acclerating past the speed of light. (Which, in retrospect, is the solution devised by the creators of Futurama!)

If you factor in something like Alcubierre's warp drive, which avoids relativistic effects by keeping the real acceleration of the contents of the warp "bubble" zero, then this gets really interesting. The creation of an Alcubierre warp bubble requires massive amounts of negative energy, but given that one of the characteristics of the Zero Point Field is negative energy, it seems like some sort of love connnection should be possible here.

While the paper proposes metric engineering to decouple gravity and inertia, it doesn't talk about generating gravity, but it seems to me if you can do the one, the other shouldn't be out of bounds. Which means that this gives me both FTL drive as well as artificial gravity, all from the same source, with a minimum of handwaving.

Now, I'm considering all of the wacky thing you could do with the ability to generate gravity. A rational basis for a "tractor beam"?