Progress in revolutionary propulsion physics
Marc G. Millis
Abstract and summary · read the original at the source
In one page
Marc Millis ran NASA’s Breakthrough Propulsion Physics project, and here, writing from the Tau Zero Foundation, he condenses the 739-page volume he and Eric Davis edited for the American Institute of Aeronautics and Astronautics into a single conference paper. Its subject is what physics would have to yield for a craft to move without carrying propellant, for interstellar distances to become traversable, and for an onboard energy source to match both. Millis sorts more than three dozen approaches by which of those three goals they address and how far each has travelled through the scientific method, and he is exact about where the field stands: the questions are now sharp, the make-or-break issues connect to named unsolved problems in physics, and no device is confirmed. He also hands the field a working method — judge a proposal by its rigour rather than by guessing at its feasibility, count reliable knowledge as success, publish the null results — and then lists the next experiments to run.
Why it matters hereThis is the paper chapter 1 borrows its evidence ladder from: Millis states, for a whole field at once, how to tell a rigorous claim from a loose one and what counts as progress when the breakthrough has not yet arrived. For chapters 4 and 13 it is the map — space drives, warp drives, wormholes, vacuum energy and the unfinished physics behind each, laid out with the specific next measurement attached to every one.
What it claims
01The three goals that organise the whole field, taken from the NASA Breakthrough Propulsion Physics project, are propulsion that needs no propellant, faster-than-light travel, and energy breakthroughs to power the first two; Millis itemises more than three dozen approaches against them, notes that none is at the stage of a confirmed working device, and grades each by how far it has moved through the scientific method.Sect. IV, Notional Propulsion Approaches; Table 1
Published and peer-reviewed02A space drive — a craft that moves by interacting with the space around it instead of ejecting propellant — changes the arithmetic of a mission, because the energy required drops from an exponential function of trip velocity to a squared one; its two make-or-break issues are conservation of momentum and net external thrust.Sect. I, Introduction; Sect. IV, Space Drive Physics
Published and peer-reviewed03The quantum vacuum is the leading candidate for the reaction medium such a drive would push against, and the size of the prize is exactly what is unsettled: depending on the factors chosen for the calculation, the equivalent mass density of quantum vacuum energy is quoted anywhere from 10 to the minus 26 up to 10 to the 98 kilograms per cubic metre, while the origin of inertial frames themselves remains undetermined.Sect. IV, Conservation of momentum; Sect. V, Unfinished Foundations of Physics
What to watch04Comparing the two space-warping routes on energy, Millis reports that a wormhole is the cheaper one: roughly 10 to the 46 joules held below the ambient vacuum level — the paper’s term is negative energy — would open a faster-than-light wormhole about 100 metres across, whereas the same energy spent on a warp bubble of equal diameter buys only about one per cent of light speed.Sect. IV, Faster-Than-Light Implications of General Relativity, citing Frontiers of Propulsion Science p. 491
Published and peer-reviewed05On drawing energy from the vacuum, the paper reports two established results and one open question: a net thrust from a dynamical Casimir effect has been shown theoretically, though that first embodiment is feebler than a photon rocket; energy conversion is possible in principle without violating thermodynamics, as in Forward’s Casimir battery, but as a one-shot device that must then be recharged; and whether the vacuum can be tapped continuously turns on whether it can be treated as a plenum, and on whether quantum electrodynamics or stochastic electrodynamics is the right formalism.Sect. IV, Quantum Vacuum, citing Frontiers of Propulsion Science Ch. 12 and p. 571, 577-587
Published and peer-reviewed06The next-step list is specific and still open: use ultrahigh-intensity tabletop lasers to test the space-warping assertions of general relativity, independently repeat Tajmar’s anomalous frame-dragging near rotating cryogenics and Woodward’s inertia experiments, use micro- and nano-structure engineering to probe the quantum vacuum across many geometries and materials, run vacuum-energy experiments with negative-index and ultra-high carrier-density materials and superconductors, and publish null results so the community stops re-investing in dead ends.Sect. III, Novice Orientation; Sect. VI, Next Step Research
What to watch
Read it · abstract
Abstract
Prior to 1988, traversable wormholes were just science fiction. Prior to 1994, warp drives were just fiction. Since then, these notions matured into published scientific discourse, where key issues and unknowns continue to be raised and investigated. In 2009, the American Institute of Aeronautics and Astronautics published a peer-reviewed, expansive technical volume on these and other investigations toward breakthrough propulsion. This paper summarizes the key assertions from that 739-page volume, describing the collective state-of-the-art and candidate research steps that will lead to discovering if, or how, such breakthroughs might finally be achieved. Coverage includes: prerequisites for space drive physics, manipulating gravity or inertia for propulsion, lessons from superconductor experiments, null results with "lifters", implications of photon momentum in media, quantum vacuum physics, and the faster-than-light implications of general relativity and quantum non-locality.
The way in
https://arxiv.org/abs/1101.1063Paper IAC-10-C4.8.7, presented at the 61st International Astronautical Congress, Prague, 27 October to 1 November 2010, and carrying the line ‘Copyright 2010 by Marc G. Millis. Published by the International Astronautical Federation, with permission and released to the International Astronautical Federation to publish in all forms.’ The author version is free to read on arXiv as 1101.1063, posted 5 January 2011, and that record carries the arXiv non-exclusive distribution licence version 1.0 — checked on the arXiv abstract page on 2026-09-08 — which is not a Creative Commons licence, and no Creative Commons statement appears in the text. So this sheet carries the summary, the claims and the author’s own abstract and sends the reader to the source. Millis writes from the Tau Zero Foundation, Fairview Park, Ohio. The 739-page volume he is summarising is Frontiers of Propulsion Science, edited with Eric W. Davis, volume 227 of Progress in Astronautics and Aeronautics, AIAA 2009; page references in the claims below are to that book as cited in the paper. Two companion sheets in this library carry the NASA programme Millis led: the programme overview at /library/stm-aa880eadcb and the 1997 workshop proceedings at /library/stm-df8f3b69bc.
How to cite it
Marc G. Millis (2010) Progress in revolutionary propulsion physics. arXiv:1101.1063
Where it sits in the curriculum
The evidence ladderThe metric, warp drives and wormholesThe unified pictureEnergy from the vacuum