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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

#141

Post by Dylan16807 »

Steuard wrote: post #132
Dylan16807 wrote: post #114

Earlier quoted context omitted.

>Despite this coming from a large group of scientists with top-notch credentials, that was immediately doubted by almost the entire physics community You make it sound like the scientists reporting it didn't doubt it.

Well, that's a funny question, right? On the one hand, they really were careful in their announcement to indicate "we're not sure about this". They were clearly making a real attempt to exercise proper scientific skepticism of such a remarkable result. But on the other hand, they were willing to make that public announcement in the first place. If they'd really felt the same level of skepticism that most of the rest…

At the time I saw it as a big request for help in finding the experimental oversight. They had tried pretty hard to rule everything out, and they wanted fresh eyes.

Re: What we know about the EmDrive and Cannae Drive

#143

Post by jdjdps »

Retra wrote: post #134
mng2 wrote: post #123

Earlier quoted context omitted.

One of my profs told the class (NucE) that after the cold fusion announcement, people would come around the department to furtively ask for heavy water and such. So you can bet that smart people aren't going to pass up the opportunity to confirm what would be a major scientific discovery.

That is one of my arguments against homeopathy: We've got a world full of bright young medical students looking for cheap and easy research to do that will lead to positive results. If they haven't proven homeopathy effective, it's because it isn't.

Oh no no. Thats not how it works at all. People only look in places where they expect to find things. Thats why we dont rub sticks together all day when building a nuclear reactor. Its also why it can take centuries to correct mistaken scientific conclusions. While I fully expect homeopathy to be bunk, if it is not then I would not be surprised that it has not been scientifically verified. Market forces/darwian selection/distributed search algorithms that we tend to find in the real world are not finding global minimums, only local minimum. This makes it tricky to construct arguments of the form, well if we havent found a solution of form x then x must be impossible within frame y.

Re: What we know about the EmDrive and Cannae Drive

#144

Post by narrator »

narrator wrote: post #25

I think this technology, if real, should be shut down and controlled by the government. Officially, it should be denied and declared to be quackery. It would likely cause grave security problems. Just think of the capabilities this would give the bad guys. We already went too far with technology with the discovery of nuclear weapons and enormous effort has been invested in controlling that technology for decades. The…

Hmm.. I was hoping somebody would write a well reasoned response to why this point of view is wrong so I could reasonably change my mind. Well at least I got it out there, even if I had to sacrifice karma.

Re: What we know about the EmDrive and Cannae Drive

#146

Post by jdjdps »

Steuard wrote: post #4

This is not worth getting excited about. Really. Extraordinary claims require extraordinary evidence. These drives would violate conservation of momentum.[0] Conservation of momentum is built in to the known laws of physics at an extraordinarily deep level. It is obviously not impossible that our known laws are wrong, but the alternative would be to somehow produce a radically different set of physical laws that neve…

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 them from within the walls of science, from the walls of Freedom. Yeah muh Science/freedom/nationalism/whatever makes me feel safe by allowing me to feel like I belong and satisfies a psychological need to construct a them and us world. Ffs. Grow up. Seriously hacker news. Grow up. Please, please humanity, grow up. Arrrrgggghhhh. I cant even. - Edited to remove swear words

Re: What we know about the EmDrive and Cannae Drive

#147

Post by jdjdps »

tjradcliffe wrote: post #99
jcoffland wrote: post #46

Earlier quoted context omitted.

Really what's the difference. Either we can fit it in to our models or we have to change the models. It always bothers me that so many people in the scientific community speak of our scientific models of the physical world as if they were truth itself. All models are flawed and only imitate reality by definition. We must accept that our models are only a glimpse of the real thing. We barely manage to grok our own pla…

> Why can't we admit that what we currently know only seems impressive to a few moderately advanced apes but in reality it is likely only tiny drop in the bucket compared to the knowledge our universe holds. Because that would be to deny without any reason but empty speculation that what a small group of scientists have done in the past 300 years is a singularly impressive achievement, adding more to human understand…

Don't you think thinkers have always thought this at every point of time in history? The answer is yes they have. There have been large innaccuracies discovered in our models before. So what makes you think that it's so different this century? I'm not saying the these drives work, just that appearing to fundamentally violate our models makes it unlikely to be a real effect. But it isn't impossible, lets not be too self assured here. Pride makes you feel good, and bringing emotion into your reasoning is rarely a good thing where science is concerned.

Re: What we know about the EmDrive and Cannae Drive

#148

Post by Confusion »

Retra wrote: post #134
mng2 wrote: post #123

Earlier quoted context omitted.

One of my profs told the class (NucE) that after the cold fusion announcement, people would come around the department to furtively ask for heavy water and such. So you can bet that smart people aren't going to pass up the opportunity to confirm what would be a major scientific discovery.

That is one of my arguments against homeopathy: We've got a world full of bright young medical students looking for cheap and easy research to do that will lead to positive results. If they haven't proven homeopathy effective, it's because it isn't.

There is no cheap and easy research in medicine when it comes to showing that some substance heals people, which is what if often comes down to, because the actual mechanism is unknown.

You can't show something as simple as aspirine 'works' by setting up a lab experiment without test subjects. And as soon as you involve those, it becomes legally complex, expensive, time consuming and hard.

You simply can't compare medical experiments to physics experiments. A physics experiment can be set up to be extremely controlled. If you observe some effect, the number of things it could be due to is very small.

A medical experiment requires people with all their messiness and possibly confounding variables. If you observe some effect, there are zounds of possible explanations. Controlling for all of them requires many test subjects. That makes it expensive, time consuming and hard.

Even a medical experiment on human cells in a petri dish is infinitely more complex than a physics experiment, in terms of variables involved.

Re: What we know about the EmDrive and Cannae Drive

#149

Post by madaxe_again »

Steuard wrote: post #4

This is not worth getting excited about. Really. Extraordinary claims require extraordinary evidence. These drives would violate conservation of momentum.[0] Conservation of momentum is built in to the known laws of physics at an extraordinarily deep level. It is obviously not impossible that our known laws are wrong, but the alternative would be to somehow produce a radically different set of physical laws that neve…

Please do explain dark energy, given that all of physics is known and in the can?

Nothing is ever cut and dry, or proved - just commonly accepted and proved within our current paradigm - there's plenty to suggest that we've got the nature of reality fundamentally wrong.

Re: What we know about the EmDrive and Cannae Drive

#150

Post by Confusion »

Steuard wrote: post #52
dicroce wrote: post #21

Earlier quoted context omitted.

What about this well known, tested and well accepted effect: http://en.wikipedia.org/wiki/Casimir_effect I'm not sure this working implies what you think it does.

I'm not sure what you're getting at, either. The Casimir effect is real, absolutely. I think it was an exercise in one of my quantum field theory classes. In particular, the Casimir effect is something that you can compute entirely within the structure of existing physics, and it doesn't violate any conservation laws. Now, if you suggest that I can somehow extract the Casimir energy without having put the same energy…

A quantum field theory class isn't enough to actually understand and explain a Casimir experiment if you want to go beyond the 'shut up and calculate' approach. Being able to compute the Casimir force is insufficient for understanding and explaining the entire experiment.

In a Casimir experiment, which closed system can you define in which you require conservation of energy? How do you calculate the total energy in the system in the 'before' and 'after' configurations?

How does separating two plates put energy into that system in such a way that it can subsequently manifest itself as the Casimir force? Does separating the plates increase the zero point energy and is that subsequently decreased by the Casimir force? Is it known to be possible to change the zero point energy like that?

Arguing violations of the laws of physics is not very interesting if we can't microscopically pinpoint what happens in the first place. Which can be surprisingly hard: it took decades to properly explain Laplace's demon.

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