6 ms·

I don't think really any scientists in the relevant fields actually think it's an interesting mystery. Lots of people make extraordinary claims about new theori

I don't think really any scientists in the relevant fields actually think it's an interesting mystery. Lots of people make extraordinary claims about new theories or perpetual motion machines, but those claims frequently get reported on a disproportionately large amount. 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.

maaku 11y ago
> Lots of people make extraordinary claims about new theories or perpetual motion machines. Such claims don't often get replicated by multiple, independent labs, as is the case here.
- moron4hire 11y ago
  And they seem to be basing their work on "Einstein was right, we just didn't fully understand what it meant."
- crusso 11y ago
  I'm not up on every instance of "replication" -- but so far, the ones I've read about have been really shoddily performed. http://io9.gizmodo.com/no-german-scientists-have-not-confirmed-the-impossibl-1720573809/1720737686 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.
  - austinz 11y ago
    I am skeptical about the EmDrive (although I would very much like it to be real), and my opinion on the drive or its theoretical underpinnings is not really relevant, given my lack of knowledge about the field. But I don't think that writeup is very good either: 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.
    - DavidSJ 11y ago
      Pardon my ignorance, but I don't think anyone seriously doubts that the null article produces no thrust. So it's not a question of whether the null article's production of thrust disproves the efficacy of anything. It's a question of whether the experimental setup which measured that thrust is trustworthy.
      - taneq 11y ago
        Holy triple negative batman! Do you mean that nobody thinks the null article produces thrust? Or did I parse that wrong?
        DavidSJ 11y ago
        You have the right parity but there is a slight semantic difference between that and what I said. Sorry that I wasn't so clear. I'll try again. 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.
        taneq 11y ago
        Agreed on the semantic differences, I missed that one. > "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!
      - austinz 11y ago
        I'm not saying the experiments were trustworthy or conducted properly. Only that the author of the article misunderstood the experimental setup. (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.)
- mcnamaratw 11y ago
  If you read the papers, the claims are not very well backed by independent experiment. (The claims are 'replicated' meaning lots of people repeat them!) There's little data and what there is is right at the limit of measurement error. Results from different groups conflict wildly. Tech Review is a PR rag, not a scientific publication.
51Cards 11y ago
Considering that the 2 rounds of NASA testing are now undergoing peer review it seems that some "...scientists in the relevant fields actually think it's an interesting mystery." 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-emdrive-will-undergo-peer-review-that-it-wont-pass/ http://www.popularmechanics.com/space/news/a20076/the-emdriv...
gaur 11y ago
> "Einstein was wrong!"-type articles I like popular articles about dark energy. About the only thing you learn from them is "Einstein called the cosmological constant his greatest blunder!".
- raattgift 11y ago
  Removing the CC from the normal form of the Einstein Field Equations was what he considered his 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.
keeperofdakeys 11y ago
A famous example of this was polywater, https://en.wikipedia.org/wiki/Polywater https://en.wikipedia.org/wiki/Polywater.
- ridgeguy 11y ago
  Ironically, it was Boris Derjaguin's participation in the polywater debacle that caused many to dismiss him when he claimed to have synthesized diamond by chemical vapor deposition, at pressures far below the thermodynamic stability region for diamond. 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.
Aelinsaar 11y ago
"Einstein Was Wrong- Click here to find out why!". That's the real, ugly truth. This is the endpoint of clickbait, a kind of Brandolini Black Hole.

maaku 11y ago

> Lots of people make extraordinary claims about new theories or perpetual motion machines. Such claims don't often get replicated by multiple, independent labs, as is the case here.

moron4hire 11y ago
And they seem to be basing their work on "Einstein was right, we just didn't fully understand what it meant."
crusso 11y ago
I'm not up on every instance of "replication" -- but so far, the ones I've read about have been really shoddily performed. http://io9.gizmodo.com/no-german-scientists-have-not-confirmed-the-impossibl-1720573809/1720737686 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.
- austinz 11y ago
  I am skeptical about the EmDrive (although I would very much like it to be real), and my opinion on the drive or its theoretical underpinnings is not really relevant, given my lack of knowledge about the field. But I don't think that writeup is very good either: 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.
  - DavidSJ 11y ago
    Pardon my ignorance, but I don't think anyone seriously doubts that the null article produces no thrust. So it's not a question of whether the null article's production of thrust disproves the efficacy of anything. It's a question of whether the experimental setup which measured that thrust is trustworthy.
    - taneq 11y ago
      Holy triple negative batman! Do you mean that nobody thinks the null article produces thrust? Or did I parse that wrong?
      - DavidSJ 11y ago
        You have the right parity but there is a slight semantic difference between that and what I said. Sorry that I wasn't so clear. I'll try again. 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.
        taneq 11y ago
        Agreed on the semantic differences, I missed that one. > "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!
    - austinz 11y ago
      I'm not saying the experiments were trustworthy or conducted properly. Only that the author of the article misunderstood the experimental setup. (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.)
mcnamaratw 11y ago
If you read the papers, the claims are not very well backed by independent experiment. (The claims are 'replicated' meaning lots of people repeat them!) There's little data and what there is is right at the limit of measurement error. Results from different groups conflict wildly. Tech Review is a PR rag, not a scientific publication.

51Cards 11y ago

Considering that the 2 rounds of NASA testing are now undergoing peer review it seems that some "...scientists in the relevant fields actually think it's an interesting mystery." 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-emdrive-will-undergo-peer-review-that-it-wont-pass/ http://www.popularmechanics.com/space/news/a20076/the-emdriv...

gaur 11y ago

> "Einstein was wrong!"-type articles I like popular articles about dark energy. About the only thing you learn from them is "Einstein called the cosmological constant his greatest blunder!".

raattgift 11y ago
Removing the CC from the normal form of the Einstein Field Equations was what he considered his 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.

keeperofdakeys 11y ago

A famous example of this was polywater, https://en.wikipedia.org/wiki/Polywater https://en.wikipedia.org/wiki/Polywater.

ridgeguy 11y ago
Ironically, it was Boris Derjaguin's participation in the polywater debacle that caused many to dismiss him when he claimed to have synthesized diamond by chemical vapor deposition, at pressures far below the thermodynamic stability region for diamond. 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.

Aelinsaar 11y ago

"Einstein Was Wrong- Click here to find out why!". That's the real, ugly truth. This is the endpoint of clickbait, a kind of Brandolini Black Hole.