# Another 'propellantless drive'... scam? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [April 20, 2024, 3:55pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552 "2024-04-20T15:55:56Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [August 29, 2025, 7:16pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/41 "2025-08-29T19:16:31Z")
Reminds me of the reactionless Dean drive. But that was in a science _fiction_ magazine and John Campbell was always a pushover for flakes (cf. Dianetics). ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [August 29, 2025, 8:01pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/42 "2025-08-29T20:01:59Z")
> [@Balance](#): > > I wouldn’t immediately say that “propellantless” is a guaranteed indication of nonsense. Yeah. “Reactionless” is better, since even “drives” like sails that don’t use propellant depend on action/reaction to move. They just don’t provide the propellant or force themselves. > [@Hari\_Seldon](#): > > Reminds me of the reactionless Dean drive. Or the “gravity polarizer” and “thruster” reactionless drives of Niven’s Known Space series. ---
**Author:** ![Ancient\_Nerd](https://avatars.discourse-cdn.com/v4/letter/a/ed655f/32.png) [@Ancient\_Nerd](https://boards.straightdope.com/u/Ancient_Nerd)\ **Post date:** [August 29, 2025, 8:18pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/43 "2025-08-29T20:18:32Z")
Remember EEstore? A ceramic capacitor that could match the energy density of a battery for the electric car market. Chemistry stores energy by tearing molecules apart. Dielectrics store it by stretching them a little. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 29, 2025, 9:52pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/44 "2025-08-29T21:52:40Z")
> [@Ancient\_Nerd](#): > > Dielectrics I read that as “Dianetics” and I believe that somebody would have made that claim. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 29, 2025, 10:41pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/45 "2025-08-29T22:41:05Z")
> [@Hari\_Seldon](#): > > Reminds me of the reactionless Dean drive. But that was in a science _fiction_ magazine and John Campbell was always a pushover for flakes (cf. Dianetics). Reminds me of the Alcubierre drive for FTL travel, which is nonsense presented as speculative fact. Needless to say, Miguel Alcubierre was a big Star Trek fan as a youth. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 29, 2025, 11:05pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/46 "2025-08-29T23:05:00Z")
I mean, it would work, if you could find the right material. Which you almost certainly can’t. But the math is all solid. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 29, 2025, 11:33pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/47 "2025-08-29T23:33:03Z")
What about the fundamental violation of causality? Which stems from the relativistic premise that the speed of light is not actually a “speed”, but a fundamental property of spacetime? _There was a young lady named Bright Whose speed was far faster than light; She set out one day In a relative way And returned on the previous night._ ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 29, 2025, 11:37pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/48 "2025-08-29T23:37:17Z")
Is causality absolute to begin with? Everyone always seems to start by assuming that, but maybe that’s just a wrong assumption. ---
**Author:** ![We\_re\_wolves\_not\_werewolves](https://avatars.discourse-cdn.com/v4/letter/w/838e76/32.png) [@We\_re\_wolves\_not\_werewolves](https://boards.straightdope.com/u/We_re_wolves_not_werewolves)\ **Post date:** [August 29, 2025, 11:37pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/49 "2025-08-29T23:37:20Z")
> [@Stranger\_On\_A\_Train](#): > > Theranos has become the cautionary tale for this because it should have been obvious that the way the technology was purported to work was never viable I don’t disagree, but it is easy to say that in hindsight. I mean the freaking CEO of the Cleveland Clinic was vouching for Holmes to any investor that asked! ---
**Author:** ![Ancient\_Nerd](https://avatars.discourse-cdn.com/v4/letter/a/ed655f/32.png) [@Ancient\_Nerd](https://boards.straightdope.com/u/Ancient_Nerd)\ **Post date:** [August 30, 2025, 1:06am UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/50 "2025-08-30T01:06:26Z")
> [@Exapno\_Mapcase](#): > > I read that as “Dianetics” and I believe that somebody would have made that claim. Dielectrics are used in electronics. A capacitor is a component, a sandwich of metal and an insulator. The insulator can be air or some other material. EEstor was a company that came and went about ten years ago. They were working on a dielectric material and promised that it would provide orders of magnitude better energy density than was really possible. They claimed it could be used in a capacitor instead of batteries in electric vehicles. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 30, 2025, 1:26am UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/51 "2025-08-30T01:26:04Z")
To be fair, capacitors probably will, eventually, surpass batteries for storage of electrical energy. But they’re not there yet. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 30, 2025, 3:36am UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/52 "2025-08-30T03:36:11Z")
Whoosh. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [August 30, 2025, 4:10am UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/53 "2025-08-30T04:10:35Z")
> [@wolfpup](#): > > What about the fundamental violation of causality? Maybe it doesn’t hold, and it’s just human bias that it should. Maybe anything that goes FTL splits off or diverts into an alternate universe and therefore can’t affect its _own_ past. Maybe changing the past is flatly impossible and attempts to do so will fail. Or maybe there’s some unknown physical law that prevents FTL/time travel (my personal belief). The latter possibility is a reason I consider FTL a useful concept to look into. Not because I think it’s _possible,_ but because FTL & time travel keep popping up in physics until somebody goes to the effort of demonstrating why _that_ _particular_ method won’t work. To me that looks like there’s some underlying law involved we don’t know yet; I’m reminded of the period before the Laws of Thermodynamics were formulated and respectable scientists kept coming up with perpetual motion machines that had to be disproven one by one because nobody knew _why_ they weren’t possible. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 30, 2025, 2:43pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/54 "2025-08-30T14:43:30Z")
> [@Chronos](#): > > To be fair, capacitors probably will, eventually, surpass batteries for storage of electrical energy. I don’t know about that. How much better can supercapacitors get? Other things being equal, the more charge you store, the greater the voltage gradient across the dielectric. Until at some point it is going to exceed the breakdown point of any physical dielectric material. Without some more research I don’t know how close to that limit we are. But I rather doubt if multiple orders of magnitude improvements are possible? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 30, 2025, 4:25pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/55 "2025-08-30T16:25:02Z")
> [@We\_re\_wolves\_not\_werewolves](#): > > I don’t disagree, but it is easy to say that in hindsight. I mean the freaking CEO of the Cleveland Clinic was vouching for Holmes to any investor that asked! I don’t know about the CEO of the Cleveland Clinic but there were plenty of experts in microfluidics who directly told Holmes that what she dreamed of was completely unfeasible, and anyone with clinical experience in dealing with blood knows what a difficult substance it is to work with and remove from instruments. When I first heard of the concept (circa 201?"0 or 2011, well before the scandal broke) I remember first thinking, “How could that possibly work?” but I assumed that the claims of doing hundreds of tests were just typical SiVal bombast and that the device would do a handful of tests using disposable ‘lab-on-a-chip’ technology or maybe some kind of gas chromatography–mass spectrometry approach to look for specific biomarkers. When they started putting out animated ‘demos’ I immediately recognized that it was nonsense because I actually worked on a somewhat similar (but legitimate) device for a real biomedical company and knew something of all of the contamination and control problems they were having even with dealing with much larger volumes of blood and single use pipettes and sensors to run just a small suite of tests. > [@Chronos](#): > > To be fair, capacitors probably will, eventually, surpass batteries for storage of electrical energy. But they’re not there yet. Unlikely, at least for long term storage. The problem with capacitors isn’t just the limit of charge density on energy storage but the exponential curve of discharge makes it inherently difficult to linearize the output over any significant range, which for most applications is crucial. For short periods it is possible to convert and store or mediate energy released from a ‘supercapacitor’ mechanically (in flywheels, springs, et cetera) or inductively (provided you don’t have a problem with a powerful magnetic field in the area) but the real application for high capacity capacitors is to buffer transient inputs or provide short bursts of power throughput from a lower power storage or generation source. > [@Der\_Trihs](#): > > The latter possibility is a reason I consider FTL a useful concept to look into. Not because I think it’s _possible,_ but because FTL & time travel keep popping up in physics until somebody goes to the effort of demonstrating why _that_ _particular_ method won’t work. To me that looks like there’s some underlying law involved we don’t know yet; I’m reminded of the period before the Laws of Thermodynamics were formulated and respectable scientists kept coming up with perpetual motion machines that had to be disproven one by one because nobody knew _why_ they weren’t possible. There are plenty of solutions in general relativity which can exist mathematically but have no apparent physical instantiation. Cosmic wormholes are an example; they definitely exist as a solution to the Einstein field equations but their termini should collapse upon themselves or expand indefinitely (depending on the energy density relative to the causal domain they are in). In order to have a stable, traversable wormhole would require a specific type of field with a just-so balance of negative energy density so that the termini neither expands nor contracts. We don’t have any direct evidence for the existence of such a field or the matter that would allow it to be maintained in a stable configuration, so traversable wormholes _probably_ don’t exist but nothing in current physics prohibits them. Global causality is strictly an assumption and here is no actual reason to expect strict causality beyond our experience with the everyday world. We know that causality doesn’t hold in quantum mechanics unless you assume a time-symmetric interpretation or non-local hidden variables, which breaks other physics. As for Dr. Charles Buhler and his purported propellantless thruster there doesn’t seem to be any more news in the last year and change beyond [a somewhat credulous _Popular Mechanics_ article](https://www.popularmechanics.com/space/rockets/a64323665/overcoming-earths-gravity/), and certainly no peer-reviewed research or even a preprint laying out any theoretical basis or showing their experimental setup, nor does there seem to be any pitch for investment or other obvious scams. So, I’m still guessing that this is some basic experimental error or a would-be innovator just desperately hoping to have discovered a new principle of physics despite a lack of good theory or independent validation. Stranger ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 30, 2025, 5:10pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/56 "2025-08-30T17:10:14Z")
> [@Stranger\_On\_A\_Train](#): > > Unlikely, at least for long term storage. The problem with capacitors isn’t just the limit of charge density on energy storage but the exponential curve of discharge makes it inherently difficult to linearize the output over any significant range, which for most applications is crucial. I wouldn’t have thought that was the major issue? We’re probably not going to use ‘raw’ capacitor storage. Switching power supply converters have been around for quite a while now. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [August 30, 2025, 5:21pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/57 "2025-08-30T17:21:28Z")
At this point if anyone ever could actually devise a real propellantless\* drive, their biggest problem would be convincing mainstream science and physics that they weren’t a nut or a fraud **∗** In the interests of respecting multiple conservation laws I’ll say something functionally equivalent to a propellantless drive; e.g. something that could couple to the pseudo-absolute framework of the Cosmic Microwave Background, or what have you. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [August 30, 2025, 5:36pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/58 "2025-08-30T17:36:54Z")
> [@Lumpy](#): > > their biggest problem would be convincing mainstream science and physics that they weren’t a nut or a fraud See the SF story ‘Toy Shop’ by Harry Harrison… 🙂 ---
**Author:** ![We\_re\_wolves\_not\_werewolves](https://avatars.discourse-cdn.com/v4/letter/w/838e76/32.png) [@We\_re\_wolves\_not\_werewolves](https://boards.straightdope.com/u/We_re_wolves_not_werewolves)\ **Post date:** [August 30, 2025, 5:52pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/59 "2025-08-30T17:52:36Z")
> [@Stranger\_On\_A\_Train](#): > > I don’t know about the CEO of the Cleveland Clinic but there were plenty of experts in microfluidics who directly told Holmes that what she dreamed of was completely unfeasible, and anyone with clinical experience in dealing with blood knows what a difficult substance it is to work with and remove from instruments. see article here: [Cleveland Clinic taps Theranos, bets on cheaper diagnostics | Healthcare Finance News](https://www.healthcarefinancenews.com/news/cleveland-clinic-taps-theranos-bets-cheaper-diagnostics) From the article: “This relationship could open up new opportunities for both patients and physicians to be part of high-quality, low-cost healthcare,” said Cleveland Clinic president and CEO Toby Cosgrove, MD, in a statement. “Healthcare innovation is essential to making care more accessible, affordable and timely for patients.” ---
**Author:** ![pjd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pjd/32/3009_2.png) [@pjd](https://boards.straightdope.com/u/pjd)\ **Post date:** [August 30, 2025, 6:07pm UTC](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552/60 "2025-08-30T18:07:38Z")
See also ‘Belief’ by Asimov. [Previous page](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552.md?page=2) [Next page](https://boards.straightdope.com/t/another-propellantless-drive-scam/1000552.md?page=4)