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This is such a bad article. The Emdrive working as advertised does not immediately imply that conservation of momentum does not hold. There are a variety of mo

This is such a bad article. The Emdrive working as advertised does not immediately imply that conservation of momentum does not hold. There are a variety of more plausible alternatives, precisely because conservation of momentum is so well-tested. Perhaps the most famous one is that the Emdrive is pushing against virtual particles that arise from a quantum vacuum.

madaxe_again 10y ago
Indeed - it appears the author didn't read or didn't understand the paper. If the EMDrive works as postulated, then physics doesn't fall apart, and conservation of momentum isn't violated - however it does mean that our statistical view of quantum mechanics is nothing but elegant mathematical shorthand ( which remains perfectly workable for much of QM), and reality is far more de Broglie-Bohmian than commonly believed. So. The worst case (if it works as advertised) is that physics doesn't fall apart and rather a whole new field of physics opens up. Although if that field opens up it was always going to open up, so does the progression of time and therefore progress mean anything in a deterministic universe? New metaphysics too, I guess.
- krastanov 10y ago
  Guys, to both the parent and grandparent, please do not throw out word like that haphazardly. Even if you know what Bohmian mechanics or vacuum virtual particles actually means, you are just spreading rumors at this point, unless you try to define those terms. About virtual particles: First of all, the virtual particle picture is a useful picture to build intuition, the math behind it is not as simple as the picture implies. Second, no, just pushing on the virtual particles is not a magical way to save conservation of momentum - where does that momentum go after those virtual particles re-annihilate for instance? About Bohmian mechanics: How do you even reach that conclusion? This is a really wild claim, that can not be taken seriously without any argument. Bohmian mechanics already has philosophical problems (stemming from computation theory, c.f. some of Aaronson's writing) even if mathematically it is equivalent to QM in the case of a single particle. But look at how ugly its generalization to multiple particles looks like (I do concede, ugliness is not the best guide, but it is something to consider when searching for a good description of nature).
  - wyager 10y ago
    > I do concede, ugliness is not the best guide, but it is something to consider when searching for a good description of nature Ugliness is a proxy for complexity, and we should assign a lower prior probability to more complex theories. We should be (somewhat) more skeptical of theories that don't tickle our mathematical aesthetics.
  - obi1kenobi 10y ago
    The point was not to precisely define an alternative hypothesis. The point was to illustrate that the click-baity "physics is broken" view taken by the article is not warranted, and that there is very little consideration of the less-extreme alternatives.
  - madaxe_again 10y ago
    Read the paper - that was the hypothesis presented by the folks at NASA, not me. As to whether I understand pilot wave qm - I wrote a masters reaearch project on it on it, I studied physics. As to ugliness, you think schrodinger is beautiful?!
    - krastanov 10y ago
      > As to whether I understand pilot wave qm - I wrote a masters reaearch project on it on it, I studied physics. As I said, you might understand the topic, but here you just dropped a fancy term and a very big claim, without explaining the first or giving an argument for the second. My point was not to claim you do not know what you are talking about, rather that you are not helping us understand what you are talking about.
jdeisenberg 10y ago
Towards the end of the article, the author says this: "The point isn’t that physics is wrong, nor is the point that the Eagleworks team is wrong. The point is that this is the beginning stages of actual science being done to examine an effect. The most likely outcome is that momentum really is conserved and there’s something funny going on here."
- api 10y ago
  Yes, but "funny" may still involve new physics unless it turns out to be something mundane but very sneaky.
  - greglindahl 10y ago
    The most likely "cause" is (still) experimental error.

madaxe_again 10y ago

Indeed - it appears the author didn't read or didn't understand the paper. If the EMDrive works as postulated, then physics doesn't fall apart, and conservation of momentum isn't violated - however it does mean that our statistical view of quantum mechanics is nothing but elegant mathematical shorthand ( which remains perfectly workable for much of QM), and reality is far more de Broglie-Bohmian than commonly believed. So. The worst case (if it works as advertised) is that physics doesn't fall apart and rather a whole new field of physics opens up. Although if that field opens up it was always going to open up, so does the progression of time and therefore progress mean anything in a deterministic universe? New metaphysics too, I guess.

krastanov 10y ago
Guys, to both the parent and grandparent, please do not throw out word like that haphazardly. Even if you know what Bohmian mechanics or vacuum virtual particles actually means, you are just spreading rumors at this point, unless you try to define those terms. About virtual particles: First of all, the virtual particle picture is a useful picture to build intuition, the math behind it is not as simple as the picture implies. Second, no, just pushing on the virtual particles is not a magical way to save conservation of momentum - where does that momentum go after those virtual particles re-annihilate for instance? About Bohmian mechanics: How do you even reach that conclusion? This is a really wild claim, that can not be taken seriously without any argument. Bohmian mechanics already has philosophical problems (stemming from computation theory, c.f. some of Aaronson's writing) even if mathematically it is equivalent to QM in the case of a single particle. But look at how ugly its generalization to multiple particles looks like (I do concede, ugliness is not the best guide, but it is something to consider when searching for a good description of nature).
- wyager 10y ago
  > I do concede, ugliness is not the best guide, but it is something to consider when searching for a good description of nature Ugliness is a proxy for complexity, and we should assign a lower prior probability to more complex theories. We should be (somewhat) more skeptical of theories that don't tickle our mathematical aesthetics.
- obi1kenobi 10y ago
  The point was not to precisely define an alternative hypothesis. The point was to illustrate that the click-baity "physics is broken" view taken by the article is not warranted, and that there is very little consideration of the less-extreme alternatives.
- madaxe_again 10y ago
  Read the paper - that was the hypothesis presented by the folks at NASA, not me. As to whether I understand pilot wave qm - I wrote a masters reaearch project on it on it, I studied physics. As to ugliness, you think schrodinger is beautiful?!
  - krastanov 10y ago
    > As to whether I understand pilot wave qm - I wrote a masters reaearch project on it on it, I studied physics. As I said, you might understand the topic, but here you just dropped a fancy term and a very big claim, without explaining the first or giving an argument for the second. My point was not to claim you do not know what you are talking about, rather that you are not helping us understand what you are talking about.

jdeisenberg 10y ago

Towards the end of the article, the author says this: "The point isn’t that physics is wrong, nor is the point that the Eagleworks team is wrong. The point is that this is the beginning stages of actual science being done to examine an effect. The most likely outcome is that momentum really is conserved and there’s something funny going on here."

api 10y ago
Yes, but "funny" may still involve new physics unless it turns out to be something mundane but very sneaky.
- greglindahl 10y ago
  The most likely "cause" is (still) experimental error.