Centauri Dreams asked Marc Millis, former head of NASA’s Breakthrough Propulsion Physics Project, for his thoughts on so-called hyperspace propulsion, as recently published in an article called “Take a Leap into Hyperspace” (New Scientist, 5 January 2006). The article has received wide coverage because of its sensational implication that we may be much closer to a breakthrough in interstellar propulsion than anyone realized. And as discussed here in the last few days, it draws on the work of the German theoretician Burkhard Heim and the later refinements of Walter Dröscher and Jochem Häuser.
Millis’ response follows. But he leads it off with this qualification: “My assessments below are only a cursory response rather than the result of a full technical review. If I had done a full technical review, I would have submitted it to a journal. Given the level of interest, however, and the habit that many of us have to jump to conclusions (pro or con), I thought I should comment.”
With that necessary provisio, the podium belongs to Marc Millis:
First, there are many different approaches in the literature related to breakthrough propulsion, not just this one. Each is at a very early stage of inquiry. As much as we’d like the final answer NOW if any of these will lead to a real interstellar craft, that question cannot yet be reliably answered. Instead, we should be asking: “What do we work on next; what is the next step?” This is the context in which I’ve framed my comments.
On this particular approach, where Dröscher and Häuser build on the theories of Heim to suggest propulsive effects, the next logical step is to verify the assertion that the Heim theory correctly predicts the masses of subatomic particles; this assessment should be carried out in the open peer-reviewed literature so that the results and its verification are traceable (instead of by anecdote). A confirmation of this assertion, by itself, would be significant. Since this task only requires analysis, instead of experiment, this should not be too costly for the advocates to support themselves.
For those advocating the Heim theory, it would also be very useful to have a more tutorial version of Heim’s derivations (and in English) to help the greater community understand precisely what is being done. From the German 1977 paper and other text I read, I only found the assertions without the step-by-step explanations for how these were developed. The existing publications are insufficient to convey the theory.
Also, it should not be forgotten that the Heim theory and its propulsive implications are two separate issues. It seems that Dröscher and Häuser reintroduced dimensions into the Heim theory that Heim had dismissed, so even if the mass prediction claims of Heim are confirmed, there is no guarantee that the modified theory would, itself, be valid. Having this conversion step explained, and in the form of a peer-reviewed paper, would be quite helpful. As it is, I could not follow the details myself in my quick scans of the papers.
Regarding experimental tests: As much as I am a strong advocate for experimental tests, there is the issue of relative cost. Again, there are other options out there that might be worthy of support. With the Dröscher-Häuser experiments, I could not tell if their experiment was the least-expensive approach to validate (or falsify) their theory. When competing with lesser-cost options, this will be an issue. I strongly recommend that any experimental proposal be designed to be the lowest-cost experiment sufficient to clearly falsify or support the theory.
And this brings me back to the issue of the other options and research funding. Although I still track such developments in my discretionary time, the NASA Breakthrough Propulsion Physics Project is no longer funded and I know of no other group within NASA that is authorized, qualified, and funded to support such on-the-edge propulsion physics. There are pockets of activity scattered across government, industry, and academia, but these are typically small discretionary efforts. If it turns out that there are any funding sources interested in such breakthroughs, I’d recommend having a competitive research solicitation to help identify the best prospects.
For those who do not already know, I recently published overviews of the approaches that I know about, including the work that NASA and others supported. But even these papers do not encompass all the possibilities. I also published a paper on the management methods for dealing with such visionary and provocative prospects in a constructive manner, including the criteria for competitive solicitations. I hope you find these useful:
(1) Summary of options:
Marc G. Millis, Prospects for Breakthrough Propulsion From Physics, NASA TM-2004-213082 (2004 May)
(2) Management methods:
Marc G. Millis, Breakthrough Propulsion Physics Project: Project Management Methods, NASA TM-2004-213406 (2004 Dec.)
(3) Options, methods, and estimating benefits:
Marc G. Millis, “Assessing Potential Propulsion Breakthroughs”, Annals of the New York Academy of Sciences, (due out early 2006).
This Dröscher-Häuser-Heim approach is in such an early stage of development that it is premature to judge its viability. Fortunately, relatively low-cost next-steps could be taken by its proponents to help others assess the prospects, such as confirming (in the open literature) the ability of the Heim theory to predict the masses of subatomic particles, and showing the derivations and equations necessary to comprehend the other assertions.
Also, it is important to remember that there are many other approaches out there. The best way to determine which of these might merit support is to conduct a competitive research solicitation. There is no NASA funding planned for such an assessment in the foreseeable future.
Centauri Dreams note: Those who continue to follow developments in deep space propulsion will already be familiar with the Breakthrough Propulsion Physics Project. BPP looked at such controversial topics as gravity control, space drives, faster-than-light travel, and vacuum energy, and did so in a credible and efficient manner. For a total investment of only $1.6M spread over 1995 to 2002, this project produced 14 peer-reviewed journal articles, addressed 8 different research approaches, posted an award winning Web site called Warp Drive When, and garnered over 100 positive press articles for NASA.
Since funding for BPP was deferred in 2003, Millis has been actively pursuing the creation of a foundation that can serve as an alternate venue to continue and enhance research and public education toward practical interstellar flight. Centauri Dreams will have more on this work as it develops. For now, background information on the foundation (including a document outlining its charter) may be found here.