That doesn't state that they think it works or doesn't... but they are investing time to clarify which is which. And that to me qualifies as it being an "interesting mystery".
http://www.popularmechanics.com/space/news/a20076/the-emdriv...
Such claims don't often get replicated by multiple, independent labs, as is the case here.
http://io9.gizmodo.com/no-german-scientists-have-not-confirm...
I'd love for this phenomenon to be real, but the Technology Review article did not present a realistic picture of the verification attempted to date.
From the IO9 article:
> The experimental setup is so flawed that it’s continuing to produce measurable “thrust” while in null mode when it should do nothing.
From the Wikipedia page on RF resonant cavity thrusters (and corroborated by the citations):
> the 'null test article', was designed without the internal slotting that the Cannae Drive's creator theorised was necessary to produce thrust
> The null test device was not intended to be the experimental control.
The article's author seems to fundamentally misunderstand the purpose of the null test setup. Setting everything else aside, if the null articles did produce thrust, this would disprove the Cannae theory (which requires the slotted configuration), but would say nothing about the efficacy of RF thrusters in general.
Their quotes from various physicists about why the drive is probably nonsense are a lot more compelling.
(To be precise, the comment about the null thruster was made by the author in a comment on this article, and by a previous article written by the author, which this one references. It is not in the article itself.)
It sounds like you think the author is asserting that the null test article was intended as an experimental control and that its production of thrust is evidence for the null hypothesis.
I read him/her as asserting that the null test article is an experimental apparatus calibration tool, and that the reading of thrust suggests the apparatus is improperly calibrated, so that no results at all can be inferred from the experiment.
There's a difference between "I don't believe X" (which allows for ambivalence) and "I believe not X" (which does not). There's also a difference between "I believe not X" and "I have no doubt of not X".
I was pointing out that there is no dispute or even doubt about the null article's inability to produce thrust (and this would have been a better phrasing). So the question is not "what does the null article's thrust imply about various hypotheses?" It's "what does the apparatus' measurement of thrust from the null article imply about the apparatus?" GP seems to have missed this point.
> "What does the apparatus' measurement of thrust from the null article imply about the apparatus?"
That makes sense, and I think it's a good question. Thanks for clarifying!
Tech Review is a PR rag, not a scientific publication.
In fact, he was right and diamond synthesis by CVD is routine today. We probably lost about a decade of progress in diamond CVD because of Derjaguin's having been tarred with polywater, as it were.
I like popular articles about dark energy. About the only thing you learn from them is "Einstein called the cosmological constant his greatest blunder!".
It was there originally, but he realized that he could not have a static universe with a nonzero CC, so he removed it, as Hubble, Lemaitre and Friedmann had not yet demonstrated the universe is non-static. When there was overwhelming evidence of what we now call the Hubble flow, he realized that a small positive cosmological constant produces exactly that, and thus he put it back in.
What you don't usually learn in those articles about dark energy is that in the Friedman-Lemaitre-Robertson-Walker model of the standard cosmology, you have an assortment of matter fields which are characterized by density and pressure.
Matter (in the most general sense of non-gravitational field content) has positive pressure, and some matter can clump (leading to non-uniform densities, and where density is higher, so is pressure; super-dense massive objects have enormous positive internal pressure).
Dark energy is in its simplest form a field with slightly negative pressure, and with constant density (i.e., it does not clump and it does not dilute away with the expansion like the matter fields do). This constant density is the "cosmological constant". Its absolute value is very small compared to the pressure even in slight overdensities of ordinary matter (like in sparse gas and dust clouds), so it's drowned out entirely by the positive pressures in structures like galaxies or stars.
Pressure and density are terms which are in the (Robertson-Walker) metric, and the metric describes the 4-lengths of spacetime intervals. Positive pressure contracts these lengths; negative pressure increases them.
So when fields with nonzero pressure are treated as the principal generators of the metric (i.e., matter and dark energy tell spacetime how to curve), you can call the result the metric expansion (or contraction) of space.
This is from the perspective of a former physicist who is grumpy about the endless torrent of "Einstein was wrong!"-type articles. I personally feel like it's risky to allow people to pin their hopes on something that's pretty obviously bunk, but I imagine it does have some benefits. I just don't think it's worth it.