# Best way to generate energy from a reactionless thruster?

The IVO Quantum Drive is scheduled to be launched into space on June 10th this year, for realsies.

I fully expect that it will not work, because it would violate conservation of energy.

But if it did work... hey, let's write some SF about it! The obvious way to turn this into a free energy generator is to mount a bunch of reactionless drives in a ring to make them spin a shaft that drives a dynamo. That's not particularly complex, electrical generators are well-developed technology, but... it does still involve moving parts and bearings which require lubrication and maintenance. So, for the purpose of this question, let's define "best" as "most reliable and robust": if you have a thing that just produces a constant force, on demand, in any orientation, what's the best way to exploit that to produce electricity? Is there a better approach that just spinning it in a circle to turn a generator shaft?

(Note that anything that works at all will produce produce energy for free, so efficiency is not a concern here.)

• It's worth noting that the drive is (supposedly) reactionless, not energy-less. It takes electricity to power it. So generating power from it is going to be a losing proposition because entropy. Commented Mar 31, 2023 at 18:29
• @jdunlop iirc, don't reactionless drives always violate conservation laws in certain frames of reference?
– BMF
Commented Mar 31, 2023 at 18:41
• The drive apparently relies on Quantized Inertia. If it works, then there'll be waaay better ways to garner free energy. QI's creator wrote a book about it IIRC.
– BMF
Commented Mar 31, 2023 at 21:55
• @LoganR.Kearsley None. Mixed up QI with another theory. Apparently the best QI has to offer is a "horizon drive" (and the author did write a scifi book about it, although by the desc not one I'd pick up myself...). Not sure that's what this thing being launched is, though. The HD uses a spinning object under insane angular acceleration and an electromagnetic damper to produce thrust. Something, something, cosmic Unruh waves with which inertia is apparently connected. The needed "spinning object" is beyond our tech capability though.
– BMF
Commented Mar 31, 2023 at 22:40
• 'To Fail' is such a defeatist term. All data is good data, and all experiments are successful in telling us something. My prediction is that the test will somehow demonstrate a limitation in the thrust produced, in order to satisfy the all-encompassing absolute natural Law of Diminishing Returns. Commented Apr 1, 2023 at 15:59

Linear Piston - Assuming you have two of the drives and can immediately turn them on and off alternately, you can make a single linear piston like a Stirling Generator. A single drive pulling half the time against a spring or other elastic return stroke will accomplish the same thing.

Gravity Assist Passes - Larger scale. Let's say you want to move Deimos up to higher orbit around Mars. Pass one or several reactionless thruster spacecraft on a close orbit over Deimos, such that Deimos is pulled into a slightly higher orbit. Spend the rest of the spacecraft's orbit with reactionless drive re-establishing the proper angle, speed, and position to repeat over and over again, raising Deimos up over time.

Direct Orbit Changes or Spacecraft Planet - Larger Scale still. Attach a reactionless drive to a planet and make it into a spacecraft that can go anywhere without needing to worry about propellant.

Particle Accelerator / Permanent Battery - Tiny Scale. Apply the reactionless drive to individual ions and fling them through a vacuum at an electrode. Attach electrical leads at the source and target and there's an overall current.

You could possibly use the entropy-violating free-energy generating quantum drive to produce vibrations, and have vibration-powered generators take those vibrations and turn them into electricity. Although I'm not sure how you'd use the quantum drives to produce the vibrations in the first place. Otherwise you'd probably have to resort to using alternators or generators, which is probably a better idea anyways.

A frame challenge.

From the cited article

...or else they end up being a kind of perpetual motion machine. This is due to the fact that applying constant force results in constant acceleration, which means that the object’s kinetic energy increases quadratically over time, whereas the energy input increases linearly. As a result, the object’s kinetic energy will exceed the energy input, and (if this energy is collected via deceleration) there would be a net gain in energy.

If the kinetic energy of the system (what you are using to rotate the generator shaft) exceeds the energy that you are putting into it (the output from the generator) it is readily apparent that what you have is a perpetual motion machine on steroids. You are getting work out of an apparatus without either putting external energy into it or without using up the internal energy of the system. It seems to me that this device is intended to use externally supplied energy to produce thrust, not to produce more energy than was put into it. An interesting concept that came out in following links suggested by the cited article is that additional energy MAY be somehow coming from harnessing zero-point energy.

TL:DR Your requested system is akin to trying to hook up a generator to a motor, and keep the motor spinning in perpetuity without ever having to supply more energy. I posit that there has to be some as yet unknown limitation on the kinetic energy of the system.

What is of interest to science fiction, however, is the following passage from a link suggested by the cited article, Modelling the Pioneer anomaly as modified inertia

One possibility for a model of inertia is that of Haisch et al. (1994) who proposed that an accelerated object feels a magnetic Lorentz force through its interaction with a zero point field (ZPF) similar to the Unruh field (Unruh, 1976). This force is given by F = −Γω ^2 cha/> 2πc^2 where Γ is the AbrahamLorentz damping constant of the parton being oscillated, ¯h is the reduced Planck constant, ωc is the Compton scale of the parton below which the oscillations of the ZPF have no effect on it, c is the speed of light, and a is acceleration. Haisch et al. (1994) showed that this force behaves like inertia. One objection to a modification of inertia is that it violates the equivalence principle, which has recently been tested to an accuracy of 10−13 kg by Baessler et al (1999). However, this principle has not been tested at the low accelerations seen by the Pioneer craft or by stars at the edges of galaxies. (See original for an accurate rendition of the equations)

Note of particular interest is the qualification '...has not been tested at the low accelerations...'. Perhaps we are entering an era where, in order to continue expanding the thickness of the physics textbook, we will have to look at modifying many, if not all, of our physics equations with denominator terms that in effect amount to enforcing the 'Law of Diminishing Returns', just like the relativistic equation for adding velocities has modified the Galilean equation by adding a 'diminishing denominator' term. For instance, the equation F=ma has been empirically supported at accelerations normally experienced in our relativistic reference frame, but is there a need to add a qualifying denominator for the leading and trailing edge of the curve? Is it possible that we will have to recognize that 'nature abhors a straight-line curve'?

EDIT To clarify, my frame challenge is the assumption that this engine will, indeed, provide more kinetic energy velocity than the energy put into it, and thus qualify as a 'perpetual motion machine'. As long as it does not cross the threshold of 'the thrust leads to a velocity that produces kinetic energy greater than the total input thrust energy' it is not in violation of any laws. There COULD be factors at play in the engine that follow all of the rules, with some modifications to the science that we don't yet know are required, just like Newtons Laws required modifications due to relativistic factors. Relativity did not throw out the physics textbook, it just made it thicker. For instance, the Alcubierre Drive is, in essence, a drive that only requires energy, not reaction mass, for propulsion, and I know of no reference that even remotely suggests the Alcubierre Drive is a perpetual motion machine. It breaks no rules, it just requires a thicker physics textbook. If this drive does, indeed, work, it is not proof that it is a result of it being a perpetual motion machine.

ALL drives, no matter how they work, are bound by the limitation of kinetic energy to thrust input, so no drive can supply a constant acceleration beyond this limit. Yet thrust drives do work, despite this limitation, and all of the techniques that purport to turn them into perpetual motion machines (and there are a lot of them in science fiction) are based on either false assumptions or misunderstood physics. These methods mostly have in common some method that allows this thrust-energy-to-kinetic-energy barrier to be crossed.

TL:DR

This question is based on the assumption that this drive is indeed a perpetual motion machine that does cross that barrier, and not due to some as-yet-not-understood factor that requires a thicker physics textbook, not a completely re-written textbook.

• The real limitation is that it can't locally conserve energy unless it produces less thrust than a photon rocket. The fundamental claim of the technology is that it does in fact break that limit. If there's some new physics that allows explaining where the energy comes from so it's not really violating conservation, that doesn't change the practical result, that you can get unlimited energy out of it. If you can't get energy out of it, that's just saying "oh yeah, the thruster doesn't actually work after all". Commented Apr 1, 2023 at 17:25
• If you look carefully at the analysis in my first quote, by extension this graph, and thus this limit, does not just apply to this engine, it applies to ALL engines. No engine using ANY type of thrust can accelerate at a constant rate beyond a limit where the kinetic energy of the rocket exceeds the total energy of the thrust (delta v) that got the engine to that velocity. Any rocket, any form of thrust that is linearly constant, has a Law of Diminishing Returns on its velocity determined by its kinetic energy. Under constant acceleration, the graph of the instantaneous velocity is not linear. Commented Apr 1, 2023 at 17:55
• @JustinThymetheSecond I'm the one who wrote what I linked, and I stand by it. The reason that "at some point, the energy of the thrust cannot lead to an increase in velocity" is really simple and doesn't require revising Newtonian physics: it's because you run out of propellant, and then your velocity stops increasing. It just so happens to work out, that you're always going to run out of propellant before you break conservation of energy. Commented Apr 1, 2023 at 18:26
• Alcubierre drive can be used to create free energy machines. Any FTL transmitting phenomenon can by arriving before it left. (And it doesn't matter whether it's "moving space" or not, a CTC can occur all the same.)
– BMF
Commented Apr 1, 2023 at 22:05
• @JustinThymetheSecond I had difficulty seeing it until I used Desmos to make a space-time graph shift under Lorentz transformations (highly recommend, btw; there's no substitute for playing around with the transformations visually). The gist is this: any FTL motion looks like backwards time travel in an arbitrary number of STL frames (albeit highly relativistic). After completing any FTL jump, the FTL ship can take on one of those highly relativistic frames to end up influencing its own past light cone.
– BMF
Commented Apr 2, 2023 at 4:39