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What we know about the EmDrive and Cannae Drive

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Re: What we know about the EmDrive and Cannae Drive

#171

Post by btilly »

pdonis wrote: post #168
btilly wrote: post #126

Earlier quoted context omitted.

...and if you did, then you'd be on shaky ground. Extracting energy from the zero-point energy all around us no more violates conservation of energy than extracting energy from E=mc^2 does. And we can no more figure out how to do so than Einstein could figure out how to do so a century ago. Heck, simply finding an efficient way to store lots of energy that way would be a nice trick as well! We know of no reason why y…

> Extracting energy from the zero-point energy all around us Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point". > We know of no reason why you can't beat any existing battery technology by many orders of magnitude! We know more than that: we know how to store orders of mag…

Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point".

The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it. In other words the zero point energy is not necessarily the minimal configuration that can be achieved.

Thus the apparently trivial answer isn't necessarily correct.

Re: What we know about the EmDrive and Cannae Drive

#172

Post by pdonis »

btilly wrote: post #171
pdonis wrote: post #168

Earlier quoted context omitted.

> Extracting energy from the zero-point energy all around us Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point". > We know of no reason why you can't beat any existing battery technology by many orders of magnitude! We know more than that: we know how to store orders of mag…

Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point". The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it. In other words the zero point energy is not necessarily the minimal co…

> The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it.

Yes, that's because if you arrange stuff in a "vacuum" it's no longer a vacuum. In the case of the Casimir effect, you now have a pair of uncharged plates in what used to be vacuum.

The question is, how do you propose to extract net energy using this effect? It takes energy to arrange the stuff in the first place (for example, to put the uncharged plates in place)--in other words, it takes energy to perturb the "vacuum". If you run the numbers, you'll see that there's no way to get back more energy from something like the Casimir effect than it took to arrange the stuff the right way in the first place. Which is just another way of saying that the "zero point" of an actual vacuum--no stuff present at all--is still effectively the lowest energy you can achieve.

Re: What we know about the EmDrive and Cannae Drive

#173

Post by jdjdps »

pdonis wrote: post #166
jdjdps wrote: post #146

Earlier quoted context omitted.

I get really tired of these ignorant psuedo sceptic responses. It's so obviously a straw man attack it makes me cringe. Why are you so set on assuming that it is violating conservation of momentum? No one of import is claiming this. My god, authority must always be right! All who move beyond appeals to authority when constructing arguments must be decried as beyond the fringe! Heathens! Infidels! Traitors! Expell the…

> Why are you so set on assuming that it is violating conservation of momentum? Because the EmDrive experimenters themselves are saying that thrust is being produced without any exhaust--i.e., momentum is being added to the cavity in one direction, without any compensating momentum being ejected in the other direction. That violates conservation of momentum. > No one of import is claiming this. Not directly, perhaps,…

'You're supposed to question what they're saying; you're supposed to look at logical implications to see if what they're saying is all consistent.' What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible. Then saying I found their observations to be inconsistent with how I expect the world to behave given my model. A natural follow on step from this is to conclude that they have missunderstood how their experiment is constructed - there is something about the way they are performing their experiment which is not accurately reflected in the model of their experiment. For instance there might in fact be conventional exhaust escaping from the device in a manner they had not anticipated. This is fine, this is also my interpretation. But where we differ is that I am very able to imagine a world where my model is innacurate and I appreciate that sometimes things that appear to require radically different models can in fact be produced by relatively minor ammendments. And that many people I meet seem to be very unwilling to question their own models and ammend them where necessary, upsets me. It upsets me because I believe in many instances it is born of the same kinds of irrationality that the whole enterprise of rational thought was designed to fix in the first place. At times, to me, it feels like it has become just another church for people to cling to. The rigid models I percieve within public discourse on these topics are a symptom of the very same creeping irrationality that they are purportedly defending against.

Re: What we know about the EmDrive and Cannae Drive

#174

Post by jdjdps »

Steuard wrote: post #163
jdjdps wrote: post #146

Earlier quoted context omitted.

I get really tired of these ignorant psuedo sceptic responses. It's so obviously a straw man attack it makes me cringe. Why are you so set on assuming that it is violating conservation of momentum? No one of import is claiming this. My god, authority must always be right! All who move beyond appeals to authority when constructing arguments must be decried as beyond the fringe! Heathens! Infidels! Traitors! Expell the…

I honestly don't even know where to begin in responding to this. You've called me (or my words) "ignorant" and "pseudo-skeptic", you've suggested that I have relied on appeal to authority in making my arguments, and you've implied that I'm motivated by an ignorant "us vs. them" mentality. You've told me to "grow up". All of that seems like pure personal attack, rather than any sort of robust engagement with ideas. Th…

I was angry at a great deal of posts like yours over a range of topics. Perhaps in this instance the anger was missplaced. In a previous post I have worked out how to articulate my concerns: A lot of the time posts with an overtly negative tone that claim to come from a place of rationality, are in fact reactionary. They claim to be defending a core of rationality from encroaching confusion, when in fact they are a symptom of irrationality, a result of the innapropriate application of emotional reasoning to areas of life where it has no explicative power. I believe that the rigidity of the models to be found within the minds of certain kinds of folks has less to do with the defense of rationality and more to do with the defense of identity. I find it extremely irritating to deal with people who are irrationally certain in an uncertain world - especially when they justify themselves by claiming they are just being more reasoned than the next man. Having said that I can hardly claim my post was anything but an emotional outburst.

Re: What we know about the EmDrive and Cannae Drive

#175

Post by btilly »

pdonis wrote: post #172
btilly wrote: post #171

Earlier quoted context omitted.

Which can't be done because it's the zero point energy--i.e., it's the state with the lowest possible energy. If there were a lower energy state possible, we would be calling that the "zero-point". The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it. In other words the zero point energy is not necessarily the minimal co…

> The Casimir force demonstrates that the zero point of vacuum can be ABOVE the zero point of the same space with a different arrangement of stuff in it. Yes, that's because if you arrange stuff in a "vacuum" it's no longer a vacuum. In the case of the Casimir effect, you now have a pair of uncharged plates in what used to be vacuum. The question is, how do you propose to extract net energy using this effect? It take…

When you say, "If you run the numbers", what you mean is, "If you do the calculation for the operation that we know how to do then..."

And I agree. We do not know how to perform an operation that extracts net energy from the zero point energy. We have no idea how to go about it. And we have good reason to suspect that this is impossible.

We just have no proof of it.

For an analogy to a past situation like this, it is like the situation for many decades when it was known that Maxwell's demon could break the laws of entropy, but we were pretty sure it couldn't be built. And there was a century long back and forth on the topic before that was demonstrated.

Re: What we know about the EmDrive and Cannae Drive

#176

Post by pdonis »

jdjdps wrote: post #173
pdonis wrote: post #166

Earlier quoted context omitted.

> Why are you so set on assuming that it is violating conservation of momentum? Because the EmDrive experimenters themselves are saying that thrust is being produced without any exhaust--i.e., momentum is being added to the cavity in one direction, without any compensating momentum being ejected in the other direction. That violates conservation of momentum. > No one of import is claiming this. Not directly, perhaps,…

'You're supposed to question what they're saying; you're supposed to look at logical implications to see if what they're saying is all consistent.' What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible. Then saying I found their observations to be inconsistent with how I expect the world to behave given my m…

> What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible.

Conservation of momentum has been confirmed by many, many experiments; it's not just a feature of my or anyone's "model" of the world.

> there might in fact be conventional exhaust escaping from the device in a manner they had not anticipated.

Yes, that's quite possible. But as far as I can tell, the experimenters are not even considering that possibility, or checking for it.

> I am very able to imagine a world where my model is innacurate

Sure, imagining a world in which momentum is not conserved is easy. But, as I said above, experiments have shown us that we do not live in such a world.

Of course it is logically possible that momentum is conserved almost all the time, instead of absolutely all the time, and these experiments just happened to be the first ones anyone ever ran that poked reality in a place where momentum was not quite conserved. But in Bayesian terms, my prior for that being the case is much, much lower than my prior for the experimenters having made a mistake somewhere. Experimenters make mistakes all the time; but nobody has yet discovered any violation of a conservation law.

Re: What we know about the EmDrive and Cannae Drive

#177

Post by jdjdps »

pdonis wrote: post #176
jdjdps wrote: post #173

Earlier quoted context omitted.

'You're supposed to question what they're saying; you're supposed to look at logical implications to see if what they're saying is all consistent.' What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible. Then saying I found their observations to be inconsistent with how I expect the world to behave given my m…

> What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible. Conservation of momentum has been confirmed by many, many experiments; it's not just a feature of my or anyone's "model" of the world. > there might in fact be conventional exhaust escaping from the device in a manner they had not anticipated. Yes, tha…

'it's not just a feature of my or anyone's "model" of the world.'

This may just be semantics, but I dont see how you could argue that it isnt a feature of a model of the world. A neural representation of the world shared amongst a group of humans. Tested against reality in the best ways we can imagine. But it is still just a model, it is not actual reality. Are you really so sure about those priors? You are also have a very influential prior there which supposes that that if the device functions, it does so because it violates conservation of momentum. Surely you cant know this? Are there really no other explanations which fit more neatly with our current models?

Re: What we know about the EmDrive and Cannae Drive

#178

Post by astrodust »

danielweber wrote: post #97
mahranch wrote: post #58

Earlier quoted context omitted.

This is less like flush toilets and more like computers. It took nearly 50 years for the first computers to sit in consumer's home offices. It took time for the technology to be miniaturized and cheap enough to make its way to consumer electronics. Or even cell phones. We were using radio signals in hand held devices for nearly 50 years before a vast majority of consumers were walking around with phones in their pock…

If this were proven true, there would be a completely manic gold-rush of capital into the area. Flying cars that operate at less than 1/10th the energy of cars on the road now? This would very quickly move from "let's wait for NASA to do more tests" to "let's beat NASA to the test." That's all assuming it's real, of course. I'd bet against it.

It is completely useless for flying cars. It has zero use for getting things into orbit.

The only thing that's amazing about the EM Drive, if true, is that it doesn't require a propellant. It's extremely energy intensive, but since energy can be derived from a reactor or solar panels, this is often easy to overcome.

In an atmosphere solar panels are drag, and a reactor is completely insane.

Re: What we know about the EmDrive and Cannae Drive

#179

Post by pdonis »

jdjdps wrote: post #177
pdonis wrote: post #176

Earlier quoted context omitted.

> What you are doing here is saying - I will take my model of the world and check that their observations are consistent with what it predicts are physically possible. Conservation of momentum has been confirmed by many, many experiments; it's not just a feature of my or anyone's "model" of the world. > there might in fact be conventional exhaust escaping from the device in a manner they had not anticipated. Yes, tha…

'it's not just a feature of my or anyone's "model" of the world.' This may just be semantics, but I dont see how you could argue that it isnt a feature of a model of the world. A neural representation of the world shared amongst a group of humans. Tested against reality in the best ways we can imagine. But it is still just a model, it is not actual reality. Are you really so sure about those priors? You are also have…

> it is still just a model, it is not actual reality.

We have a model that includes conservation of momentum. But experiments have shown that reality also includes conservation of momentum--that that feature of the model is an accurate representation of reality.

> Are you really so sure about those priors?

Yes.

> You are also have a very influential prior there which supposes that that if the device functions, it does so because it violates conservation of momentum.

That isn't a prior; it's a hypothesis--the one the EmDrive proponents are claiming.

> Are there really no other explanations which fit more neatly with our current models?

"The experimenters have made a mistake somewhere" is another explanation which fits in more neatly with our current models. Their mistake could be that the device isn't actually producing thrust, or it could be that it's producing thrust because it's ejecting radiation out the back end which they aren't detecting. Either one of those invalidates the EmDrive proponents' claims.

Re: What we know about the EmDrive and Cannae Drive

#180

Post by jdjdps »

pdonis wrote: post #179
jdjdps wrote: post #177

Earlier quoted context omitted.

'it's not just a feature of my or anyone's "model" of the world.' This may just be semantics, but I dont see how you could argue that it isnt a feature of a model of the world. A neural representation of the world shared amongst a group of humans. Tested against reality in the best ways we can imagine. But it is still just a model, it is not actual reality. Are you really so sure about those priors? You are also have…

> it is still just a model, it is not actual reality. We have a model that includes conservation of momentum. But experiments have shown that reality also includes conservation of momentum--that that feature of the model is an accurate representation of reality. > Are you really so sure about those priors? Yes. > You are also have a very influential prior there which supposes that that if the device functions, it doe…

I give up. I think you're wrong, you think I'm wrong. I dont have time to iron out all the mistakes you are making and Im sure you feel the same way.
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