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File: 1479767429026.png (128.95 KB, 222x300, dieglocke.jpg)

No.415

Now that anti-gravity was proven to just werk, when can we expect to have flying cars just like my sci-fi animes?

http://www.sciencealert.com/it-s-official-nasa-s-peer-reviewed-em-drive-paper-has-finally-been-published

  No.416

>>415
sure, if your cars weigh like 10^-6 pounds.

  No.420

>>415
this is NOT about antigravity!
Its about a reactionless drive.
This is great news for space probes and even interplanetary spaceships (maybe) but NOT for applications here on earth.

  No.422

>This is great news for space probes and even interplanetary spaceships (maybe)

Yeah...no, no it isn't.
It MIGHT be useful for missions that last 10+ years but for everything else it's completely useless.
They are simply unable to generate enough thrust to be useful for anything not traveling outside the solar system.
And that's supposing this toy actually works.

Also, the term 'reaction-less drive' implies that it's possible to generate thrust without conserving momentum (and therefore, energy). If we admit such a thing is possible then, in theory, perpetual motion and 'free energy' machines would become possible.

So, when you say there's a possibility for reaction-less drives to work you're saying perpetual motion and 'free energy' machines may be possible, which is something you probably don't want to argue in favor of.

Also, op was obviously brewing soykaf.

  No.423

>>422
>brewing soykaf
10/10 word filters kalyx

  No.424

>>415
That doesn't mean it works, it means the paper is scientifically solid, meaning it adjusts to the standards for a paper.
There's a lot of testing to be done still, more information will probably appear in one or two years after they do further testing.

  No.426

>>424
Indeed. If it works, and it seems to do, we still need to explain how does so.

Preferably an explanation that hinges upon a missing variable rather than one that breaks things.

  No.429

>>426
the paper suggested that pilot-wave QM theories could explain the thrust. They seem to be legit.

https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory

  No.431

>>415
>There's a lot more work to be done before we can say for sure whether the EM Drive is really producing thrust – the team notes they that more research is needed to eliminate the possibility that thermal expansion could somehow be skewing the results.
This is from the article itself.

Also, there is no mention of any antigravity, which has nothing to do with this anyway.

>>429
Well, the pilot wave theory _exists_ as a theory, but it's very much not the most accepted one, and this definitely doesn't prove it anyway, but it is worth looking into.

  No.432

>>423
haven't you seen it before? it's at least 2 years old

  No.433

>>432
nah, I lurk like 99% of the time

  No.434

>>426
>Preferably an explanation that hinges upon a missing variable rather than one that breaks things.
Nope - if this changes things fundamentaly - it will be the best thing that can happen - it will advance our understandings in the right way a huge step... if not we keep as we are and learn little!

  No.435

>>431
>Well, the pilot wave theory _exists_ as a theory, but it's very much not the most accepted one, and this definitely doesn't prove it anyway, but it is worth looking into.

yes, I'm saying, if this is indeed producing thrust(my money's on it is), then it's a big piece of evidence for the pilot wave theory.

  No.436

No flying cars, but we'll be able to more efficiently get to mars in 5 hours, so that's cool I guess.

  No.437

>>436
assuming you have a kilowatt of power and a kilogram of material to push in total(which is totally unrealistic, but whatever), with .0012 mN of force, if you were travelling in a straight line from earth to mars at the closest approach you could get to mars in 6745368 seconds -- about 78 days. And you'd be moving at 8 km/s, so say goodbye to your probe when it gets there.

more interesting applications are in interstellar travel. One of these babies could get to relativistic speeds pretty fast, on much less fuel than it takes a normal rocket.

  No.438

>>437
*.0012 N. I wrote the wrong units but the calculations are right.

  No.439

>>437
>One of these babies could get to relativistic speeds pretty fast,

well, I say that, but I lied.

Still, for just a kilowatt of constant power and a kilogram of mass you could travel a light-year in..... 89 years.

Not amazing. Maybe in 50 years when we know how it works.

  No.440

>>437
>And you'd be moving at 8 km/s, so say goodbye to your probe when it gets there.
If only we had some way of decelerating. Perhaps by thrusting in the opposite direction...

  No.441

>>440
then double your travel time.

  No.462

I'm not convinced. The result of testing in the paper is indistinguishable from the margins of experimental error. We should ask ourselves "What is more likely, a well tested and established idea like conservation of momentum is wrong or is this experimental error?"

And invoking 'some hidden variable theory' without rigorous explanation is hand waving. It's style over substance.

We've seen this kind of story before with the N-ray. Everyone testing it wanted it to be true and didn't critically, skeptically, judge their own work and were fooled by themselves; we are very good at making ourselves see what we want to see.

  No.464

>>462
>What is more likely, a well tested and established idea like conservation of momentum is wrong or is this experimental error?"

as I've said before, *if* the EM drive is producing thrust it can be considered evidence for quantum interpretations under which momentum and energy are conserved. It is by no means definitely discounting conservation of momentum or energy.

That, and if conservation of energy and momentum are falsified, that is advancement of science. The goal of science is to falsify as many things as you can to narrow the field of theories which are correct. Whether it has been verified in the past is of no consequence.

  No.465

>>464
It is discounting it, they say it's reactionless with no strong explanation.

What you said in the second paragraph is true but that's not how the cards tend to fall in honing our knowledge of things. In the scientific method we tend to advance our knowledge by falsifying old theories; then those old theories become special cases. For example, General Relativity showed that Newtonian mechanics are a good low energy, low gravity approximation of relativistic physics. Lewis binding models are a decent approximation of electron cloud theory we have found with QM.

Falsifying something like "every reaction has an equal and opposite reaction" isn't making a special case, it's more like throwing everything out the window. Is it possible that we could be wrong about it? Sure, of course it is possible. I just don't see it as being likely, and I'm not going to see it as likely until there is strong data, repeatability, and more than hand waving to support it. Getting data below the error margin is akin to finding nothing at all.

  No.466

>>440
Depends on the destination. Gravity of planets can be utilized to reduce speed, although coming to a complete stop is not likely. You would need retrothrusters, but a lot of work could be done without the need for fuel/energy/time.

  No.467

>>465
>It is discounting it, they say it's reactionless with no strong explanation.

http://arc.aiaa.org/doi/10.2514/1.B36120

>If the vacuum is indeed mutable and degradable as was explored, then it might be possible to do/extract work on/from the vacuum, and thereby be possible to push off of the quantum vacuum and preserve the laws of conservation of energy and conservation of momentum. It is proposed that the tapered RF test article pushes off of quantum vacuum fluctuations, and the thruster generates a volumetric body force and moves in one direction while a wake is established in the quantum vacuum that moves in the other direction.




>and I'm not going to see it as likely until there is strong data, repeatability, and more than hand waving to support it.


I expect that data to be coming out eventually. I think it is best to reserve judgement until then.

  No.468

>>467
That's the hand wavy bit, the part you quoted. They provide no formulation (of the underlying principle) that they can make specific, testable, measurable predictions with. It's not rigorous.

And we have been seeing the data come in. People have been testing this idea since it was first proposed by Roger Shawyer 1999. He claimed that he could get 0.016 Newtons of force out of 850 watts of power. In 2010 a Chinese team claimed they got 750 mN out of 2500 watts. The NASA team got about a thousandth less force than Sawyer claimed, it was in the μN range for 17 watts. It lacks reproducibility.

We've seen how it's worked out, it has many of the hallmarks of bad experimental design you'd expect to see in pseudoscience: poor accounting for error, lack of a rigorous explanation, wildly inconsistant results. And as the accuracy of experiments has improved the predicted thrust has kept dropping, if this is a trend you'd expect it to tend to 0 as experiments get better. We can judge it now, and it looks bad.

  No.469

File: 1480732922966.png (25.85 KB, 200x127, figure19.gif)

>>468
>That's the hand wavy bit, the part you quoted. They provide no formulation (of the underlying principle) that they can make specific, testable, measurable predictions with. It's not rigorous.

pilot wave theories are rigorous, just not popular. I'd encourage you to maybe read about them before dismissing them.

>poor accounting for error


what error source isn't covered in the paper?

>lack of a rigorous explanation


if there is no known rigorous explanation of real results, does that mean the results are false or the theory needs work?

>wildly inconsistant results


looks pretty consistent to me.

  No.470

>>469
>pilot wave theories are rigorous, just not popular. I'd encourage you to maybe read about them before dismissing them.

I am aware, and I never dismissed them in previous conversation; but it's also important to note that a pilot wave theory has never been experimentally verified so pinning it as a cause, although bold and interesting if true, is somewhat vacuous at the moment. My issue is that they never mathematically detailed how pilot waves implies 'EMdrive works', this is why I say it's hand waving. If they had a detailed model we could make specific predictions that we can test, and we would have an idea of what type of results to expect. And if we didn't get those results we could falsify it and move on.

>what error source isn't covered in the paper?

Possible error from the testing apparatus is mentioned but the data is so close to the margin of error that it borders insignificance.

>if there is no known rigorous explanation of real results, does that mean the results are false

Not necessarily, but in the 21st century physics this is a huge minus for something that Sawyer had claimed to have figured out. It's another minus that none of the operating principles he originally proposed for it had been previously verified and have since been abandoned; when the result he wanted didn't come the theory just happily changed from being based off of superposition of microwaves to hidden variable theory.

In science when we test an idea and don't get the result we expected we need to consider that it might be wrong, tweaking everything to get the same (or near same) result after not getting the data you were looking for means that you're not making your idea falsifiable. It's the pattern that homeopathy goes through, scientific theories need to be falsifiable.

>or the theory needs work?

Of course.

>looks pretty consistent to me.

I'm talking about consistency between different people independently verifying the theory. There isn't any. If it worked you'd expect different, unasociated people to be able to set up the same experiment and get the same results, with the tests I mentioned we never saw that. The same person (or group) running the same experiment over and over and getting the same result isn't independent verification; in fact this is where the polywater craze came from, it's why so many people believed the N-ray was real, it's pathological science.

Should people keep testing it? Sure. If many people could precisely repeat the experiment (with higher precision) in the most recent paper that would be really cool. I'd be glad to be proven wrong. But this has had such a bad track record so far and we can't ignore that. It isn't a convincing trend.

I feel like this conversation is about to run in a circle and there isn't much to discuss until the recent result is either independently verified, or we could see it be falsified, or if dreadful colors show they'll just change it again and again if they don't get the results they were looking for. But I've enjoyed chatting.


  No.563

>>562
China claims a lot of weird stuff. They claimed to have successfully cloned a human a while back.

  No.564

>>469
>pilot wave theories are rigorous, just not popular
Well, no, as far as I can see it.

Pilot wave theories, while having some nice properties and being similar to water droplets in a nice way, do fail. Making it fit with quantum entanglement and quantum eraser experiments seems to require ad hoc hypothesising, at the very least.

Plus, there is no arguing that it is wrong in it's current form. It might be that it's due to incompleteness, but it doesn't account for special or general relativity and fitting things together in physics isn't particularly easy.

I've also not seen any real explanation as to how the pilot wave theory explains the EM drive, though I'd be very happy to see that happen.

>>562
>breaking news, China discovered everything cool, though it won't show it to us fully or prove it in any way, but they totally did it, you guys!

Jokes aside, I hope that EM drives have something real behind them.

  No.566

>>563
I thought that was some weird Korean sect that did that.
Back in the late 90s/early 00s

  No.571

>>566
Nah, what I'm thinking of was more recent. Back in like 2011 or something

  No.573

>>566
Wasn't that the Raelians?