5 ms·

Here are two nice posts by physicist John Baez with some reasons to be skeptical about the "reactionless drive": https://plus.google.com/117663015413546257905/

Here are two nice posts by physicist John Baez with some reasons to be skeptical about the "reactionless drive": https://plus.google.com/117663015413546257905/posts/WfFtJ8bYVya https://plus.google.com/117663015413546257905/posts/WfFtJ8bY... https://plus.google.com/117663015413546257905/posts/C7vx2G85kr4 https://plus.google.com/117663015413546257905/posts/C7vx2G85...

spingsprong 12y ago
"They're claiming to see a force one thousandth as big as the Chinese - probably because they are doing the experiment one thousand times more accurately. And still, some people are excited about this. " I think he's slipping from skepticism to cynicism here.
- deleted 12y ago
  [deleted]
- crusso 12y ago
  Disagree. He's being prudent and rational to hold these experiments to the same standards that we hold other more mundane ones. Hoax phenomenon and devices always seem to fail in precisely the way that this one has. As you more carefully examine the test setups, suspicious conditions of the experiment persist (like the lack of using a vacuum in the vacuum chamber), and observed phenomenon continue to diminish as the accuracy of the test equipment improves. And I use the word "fail" knowing full well that they claimed that they had positive results. If they couldn't use best practices in performance of the experiment like evacuating the vacuum chamber and they couldn't even show that their null device that wasn't designed to produce the same effect didn't work, then they have some serious problems.
readerrrr 12y ago
He seems to be makings some mistakes as well. He says: This is baloney too - but now it's graduate-level baloney. "Quantum vacuum virtual plasma" is something you'd say if you failed a course in quantum field theory and then smoked too much weed. There's no such thing as "virtual plasma". If you want to report experimental results that seem to violate the known laws of physics, fine. But it doesn't help your credibility to make up goofy pseudo-explanations. The original description might be clumsy, but the idea of empty space being full of virtual particles is not wrong. Here is Dr. Laurence Krauss's description of empty space: especially the idea that what we think of empty space is really not empty, correct? KRAUSS: That's exactly right. Empty space is a boiling, bubbling brew of virtual particles that pop in and out of existence in a time scale so short that you can't even measure them. Now, that sounds of course like counting angels on the head of a pin; if you can't measure them, then it doesn't sound like it's science, but in fact you can't measure them directly. But we can measure their effects indirectly. These particles that are popping in and out of existence actually affect the properties of atoms and nuclei and actually are responsible for most of the mass inside your body. And in fact, really one of the things that motivated this book was the most profound discovery in recent times, and you even alluded to it in the last segment, the discovery that most of the energy of the universe actually resides in empty space.
- cousin_it 12y ago
  Baez is right, there's no such thing as "virtual plasma". Just Google the phrase.
  - tobinfricke 12y ago
    To expand on that a little: http://blogs.discovermagazine.com/outthere/2014/08/06/nasa-validate-imposible-space-drive-word/#.U-N7iJs-uHd http://blogs.discovermagazine.com/outthere/2014/08/06/nasa-v... >>In the paper by White et al, they also write that the Cannae Drive “is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.” That last bit stopped me. What’s a quantum vacuum virtual plasma? I’d never heard the term, so I dropped a note to Sean Carroll, a Caltech physicist whose work dives deeply into speculative realms of cosmology and quantum theory. Carroll wrote back immediately, with a pointed message: “There is no such thing as a ‘quantum vacuum virtual plasma,’ so that should be a tip-off right there. There is a quantum vacuum, but it is nothing like a plasma. In particular, it does not have a rest frame, so there is nothing to push against, so you can’t use it for propulsion. The whole thing is just nonsense. They claim to measure an incredibly tiny effect that could very easily be just noise.” There is no theory to support the result, and there is no verified result to begin with.<<
    - JoeAltmaier 12y ago
      Huh. I thought the OP experiment WAS verification.
      - scott_s 12y ago
        Because lots can go wrong, one experiment is not a verification. Particularly when the measurements are so sensitive. And I'm aware this is the third experiment, but with a result that is so counter to basic theory, we need many more.
    - lnanek2 12y ago
      Pretty strange response, there are lots of things that prove virtual particles are a legitimate model, even for things like generating force: http://en.wikipedia.org/wiki/Casimir_effect http://en.wikipedia.org/wiki/Casimir_effect
mnl 12y ago
I'd never understand how intelligent and educated people lose it completely when it comes to Physics. They've been exposed to some PopSci tales not meant to be accurate at all and then feel entitled to be right when they figure out some nonsensical consequences by themselves -no proper maths involved ever-. It's depressing. Baez is right, of course. I've been checking the (Word-generated) "papers" from this guy's group at NASA, they're extremely shoddy: There's another report with their unstable calibration for the torsion pendulum which shows their complete lack of undergraduate lab report skills. And a poster from them where they say: "Q-thruster test articles are going to be tested in a vacuum to reduce possibility of air currents polluting the thrust signal during testing, but electrolytic capacitors in signal amplifier are not vacuum compatible"... Awesome. I've also checked the Chinese Physics B paper. Their device is completely different from this one. It's an open cavity and they only use classical EM. I don't understand very well how their thrust measurement set-up works so I hold my judgement on their claims, but at least they're trying to be legit. Violation of momentum is an extremely serious claim (in words of D.J. Griffiths, "there is no principle in Physics more sacred than that"). The Universe would look nothing like this if that were true and all the Physics that we've discovered consistent with thousands of experiments would be gone. The way they use the quantum vacuum has nothing to do with the formalism that made it possible. Several detailed QED calculations backed up by experiments to astounding precision would be completely wrong and we know that's not the case. BTW, the fundamental principle is conservation of momentum, Newton's 3rd law of motion is a consequence that sometimes doesn't hold, for instance forces between charged particles in electrodynamics don't follow the 3rd law (but approximately at low speeds). If you take into account momentum carried by the fields you get conservation of momentum back, quite nicely as well.
- jcfrei 12y ago
  The issues raised by Baez are quite substantial. I'm surprised the report was still published by NASA.
- forgotketchup 12y ago
  > I've been checking the (Word-generated) "papers" from this guy's group at NASA, they're extremely shoddy. Not defending this particular paper, but I'm curious why you highlighted the fact that it's written in Word. Just about everybody in physics these days uses Word to compose papers (Word + Mendeley is a dream, by the way). Maybe you think he's not a 'real man' because he doesn't sling raw LaTeX?
snowwrestler 12y ago
I think it's great to express detailed skepticism about experiments like these, but I find the high levels of attitude to be tiresome. It doesn't add anything of substance to the skepticism, and it seems like an anti-pattern for good science. Scientists need to maintain some level of humbleness about their certainty. Not be credulous, but not be sarcastically smug either. NASA is not universally populated with geniuses, but they're not high school idiots. I don't think they should be ridiculed for reporting a best-effort attempt to test surprising or controversial results. Otherwise how would surprising results ever be found?
- cookiemonster11 12y ago
  The skepticism is very substantiated. Read John Baez' posts maybe? Or the Paper in question?
  - snowwrestler 12y ago
    I'm talking about the mockery and sarcasm, which add nothing to the substance of Baez's posts.

spingsprong 12y ago

"They're claiming to see a force one thousandth as big as the Chinese - probably because they are doing the experiment one thousand times more accurately. And still, some people are excited about this. " I think he's slipping from skepticism to cynicism here.

deleted 12y ago
[deleted]
crusso 12y ago
Disagree. He's being prudent and rational to hold these experiments to the same standards that we hold other more mundane ones. Hoax phenomenon and devices always seem to fail in precisely the way that this one has. As you more carefully examine the test setups, suspicious conditions of the experiment persist (like the lack of using a vacuum in the vacuum chamber), and observed phenomenon continue to diminish as the accuracy of the test equipment improves. And I use the word "fail" knowing full well that they claimed that they had positive results. If they couldn't use best practices in performance of the experiment like evacuating the vacuum chamber and they couldn't even show that their null device that wasn't designed to produce the same effect didn't work, then they have some serious problems.

readerrrr 12y ago

He seems to be makings some mistakes as well. He says: This is baloney too - but now it's graduate-level baloney. "Quantum vacuum virtual plasma" is something you'd say if you failed a course in quantum field theory and then smoked too much weed. There's no such thing as "virtual plasma". If you want to report experimental results that seem to violate the known laws of physics, fine. But it doesn't help your credibility to make up goofy pseudo-explanations. The original description might be clumsy, but the idea of empty space being full of virtual particles is not wrong. Here is Dr. Laurence Krauss's description of empty space: especially the idea that what we think of empty space is really not empty, correct? KRAUSS: That's exactly right. Empty space is a boiling, bubbling brew of virtual particles that pop in and out of existence in a time scale so short that you can't even measure them. Now, that sounds of course like counting angels on the head of a pin; if you can't measure them, then it doesn't sound like it's science, but in fact you can't measure them directly. But we can measure their effects indirectly. These particles that are popping in and out of existence actually affect the properties of atoms and nuclei and actually are responsible for most of the mass inside your body. And in fact, really one of the things that motivated this book was the most profound discovery in recent times, and you even alluded to it in the last segment, the discovery that most of the energy of the universe actually resides in empty space.

cousin_it 12y ago
Baez is right, there's no such thing as "virtual plasma". Just Google the phrase.
- tobinfricke 12y ago
  To expand on that a little: http://blogs.discovermagazine.com/outthere/2014/08/06/nasa-validate-imposible-space-drive-word/#.U-N7iJs-uHd http://blogs.discovermagazine.com/outthere/2014/08/06/nasa-v... >>In the paper by White et al, they also write that the Cannae Drive “is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.” That last bit stopped me. What’s a quantum vacuum virtual plasma? I’d never heard the term, so I dropped a note to Sean Carroll, a Caltech physicist whose work dives deeply into speculative realms of cosmology and quantum theory. Carroll wrote back immediately, with a pointed message: “There is no such thing as a ‘quantum vacuum virtual plasma,’ so that should be a tip-off right there. There is a quantum vacuum, but it is nothing like a plasma. In particular, it does not have a rest frame, so there is nothing to push against, so you can’t use it for propulsion. The whole thing is just nonsense. They claim to measure an incredibly tiny effect that could very easily be just noise.” There is no theory to support the result, and there is no verified result to begin with.<<
  - JoeAltmaier 12y ago
    Huh. I thought the OP experiment WAS verification.
    - scott_s 12y ago
      Because lots can go wrong, one experiment is not a verification. Particularly when the measurements are so sensitive. And I'm aware this is the third experiment, but with a result that is so counter to basic theory, we need many more.
  - lnanek2 12y ago
    Pretty strange response, there are lots of things that prove virtual particles are a legitimate model, even for things like generating force: http://en.wikipedia.org/wiki/Casimir_effect http://en.wikipedia.org/wiki/Casimir_effect

mnl 12y ago

I'd never understand how intelligent and educated people lose it completely when it comes to Physics. They've been exposed to some PopSci tales not meant to be accurate at all and then feel entitled to be right when they figure out some nonsensical consequences by themselves -no proper maths involved ever-. It's depressing. Baez is right, of course. I've been checking the (Word-generated) "papers" from this guy's group at NASA, they're extremely shoddy: There's another report with their unstable calibration for the torsion pendulum which shows their complete lack of undergraduate lab report skills. And a poster from them where they say: "Q-thruster test articles are going to be tested in a vacuum to reduce possibility of air currents polluting the thrust signal during testing, but electrolytic capacitors in signal amplifier are not vacuum compatible"... Awesome. I've also checked the Chinese Physics B paper. Their device is completely different from this one. It's an open cavity and they only use classical EM. I don't understand very well how their thrust measurement set-up works so I hold my judgement on their claims, but at least they're trying to be legit. Violation of momentum is an extremely serious claim (in words of D.J. Griffiths, "there is no principle in Physics more sacred than that"). The Universe would look nothing like this if that were true and all the Physics that we've discovered consistent with thousands of experiments would be gone. The way they use the quantum vacuum has nothing to do with the formalism that made it possible. Several detailed QED calculations backed up by experiments to astounding precision would be completely wrong and we know that's not the case. BTW, the fundamental principle is conservation of momentum, Newton's 3rd law of motion is a consequence that sometimes doesn't hold, for instance forces between charged particles in electrodynamics don't follow the 3rd law (but approximately at low speeds). If you take into account momentum carried by the fields you get conservation of momentum back, quite nicely as well.

jcfrei 12y ago
The issues raised by Baez are quite substantial. I'm surprised the report was still published by NASA.
forgotketchup 12y ago
> I've been checking the (Word-generated) "papers" from this guy's group at NASA, they're extremely shoddy. Not defending this particular paper, but I'm curious why you highlighted the fact that it's written in Word. Just about everybody in physics these days uses Word to compose papers (Word + Mendeley is a dream, by the way). Maybe you think he's not a 'real man' because he doesn't sling raw LaTeX?

snowwrestler 12y ago

I think it's great to express detailed skepticism about experiments like these, but I find the high levels of attitude to be tiresome. It doesn't add anything of substance to the skepticism, and it seems like an anti-pattern for good science. Scientists need to maintain some level of humbleness about their certainty. Not be credulous, but not be sarcastically smug either. NASA is not universally populated with geniuses, but they're not high school idiots. I don't think they should be ridiculed for reporting a best-effort attempt to test surprising or controversial results. Otherwise how would surprising results ever be found?

cookiemonster11 12y ago
The skepticism is very substantiated. Read John Baez' posts maybe? Or the Paper in question?
- snowwrestler 12y ago
  I'm talking about the mockery and sarcasm, which add nothing to the substance of Baez's posts.