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Comment by gus_massa | Hacker News Reader

> I think what I most enjoy about the possibility of the EmDrive is that it's similar to how things were often discovered during the "golden age" of science.

There were also a lot of false discoveries. Someone made a machine that does something, and after a few iterations it was discovered that it was only a bad measurement (or a scam). It happens also with theoretical ideas, the most famous are aether and flogisto. They were good ideas, they explained a lot of experiments, but after a time it became obvious that they were wrong.

> The EmDrive is one of the rare modern situations where someone has engineered a device that shouldn't work according to what we know and the scientists are having to come up with the explanation.

The obvious explanation is that they have an error in the measurement. Probably something get very hot and the thermal effect produce a tiny force, some experiments show that it need some time to build up and it continue a little after the current is off, like a thermal effect. Another possible explanation is that the high currents produce a magnetic field that produce a tiny force. They are putting a lot of electricity and energy in a small device, and they only measure a tiny force, it's very difficult to rule out experimental errors. A similar case are the faster than light neutrinos, that were the product of a bad measurement.

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It's a very, very small effect right now, near the noise threshold. Magnetic induction from the power leads can be bigger than the effect. Testing in vacuum eliminated some other sources of noise. That's why there's such skepticism.

The encouraging thing about having some theory now is that it gives some insights into what to do to get a bigger effect. Lilienfeld built a field effect transistor in 1925. This was a major breakthrough, but wasn't pursued. He was using a copper/sulfur oxide on aluminum, sort of like a copper oxide rectifier, a known device at the time. That oxide apparently has some semiconducting properties. But lacking any theory, there was no clear way to make it better.

There was nothing to indicate that highly refined silicon (something nobody used back then) was the material to use instead of aluminum. Germanium diodes were known to rectify, but nobody understood why. Not until Bell Labs tried to figure out how germanium diodes worked and some semiconductor device physics was discovered was there forward progress.

Once the underlying mechanism started to be understood, progress was fast.

No vacuum testing has ever taken place. They've run tests in a vacuum chamber that was not evacuated.

Link? According to the article, "And last year, NASA conducted its own tests in a vacuum to rule out movement of air as the origin of the force." So either the story is wrong or you are, but both can't be right, right?

Huh, seems I'm wrong - there was an actual high vacuum test -http://arc.aiaa.org/doi/pdf/10.2514/6.2015-4083

Paywalled on that link though so I can't see the details which tend to be everything since last time a vacuum chamber was involved it wasn't actually evacuated.

A German team tested it in a vacuum. It's mentioned with sources on the EmDrive's Wikipedia page.

Yes, and that report indicates a null result. But they also indicate that the driving frequency was way mistuned for the cavity. They were driving it with a magnetron from a microwave oven, which output a frequency far from optimal. This indicates a low-budget operation, and not one in a lab with lots of microwave gear.

NASA, at least, has a microwave source with the right frequency. But they report "researchers were now working on a new integrated analytical tool to help separate EmDrive thrust pulse waveform contributions from the thermal expansion interference". That indicates this thing is still way too close to the noise threshold.

Back when cold fusion was taken seriously, I went to a Stanford talk where a physicist described their attempts to replicate the experiment. At first, he said, they had the apparatus surrounded with radiation detectors and alarms, in case it produced a dangerous burst of neutrons. After a while, they realized that wasn't going to happen. They discovered that the effect being measured was about twice background radiation. Then they discovered that people moving around the apparatus affected neutron readings by more than the measured amount. (Humans are mostly water, and thus reflect neutrons.) Finally they moved the experiment to a "neutron cube" built from lead bricks, where the background radiation was very low. The measured neutron readings went way down. That's what it's like when a phenomenon is near the noise threshold.

> That's what it's like when a phenomenon is near the noise threshold.

That's not really noise level, that's just unknown systematic errors.

he just means here are all kinds of piddly effects that will throw it off. If you switch the thing on and you get a huge effect size with high signal/noise you don't need to worry about stuff like who is standing near the tank other than to worry that they're being irradiated with fast neutrons.

If you're that low-budget why would you not just size the cavity to match a commercial microwave oven magnetron?

My understanding was that the report didn't show a null report:

The device produced positive thrusts in the positive direction and negative thrusts in the negative direction of about 20 micronewtons in a hard vacuum, consistent with the low Q factor.

Besides being tested horizontally in both directions on the torsion pendulum, the cavity was also set upwards as a "null" configuration. However, this vertical test intended to be the experimental control showed an anomalous thrust of hundreds of micronewtons that could be caused by a magnetic interaction with the power feeding lines going to and from liquid metal contacts in the setup.

(from Wikipedia)

Am I misreading this somehow?

The German team did it for a BBC documentary on "junk science" - they were looking for a null result, so while I take claims that the tech works with a pinch of salt, the same applies here.

Everybody acts to their own interests.

Ah yes, the typical "let's prove this doesn't work" so do it half-assed and then go "see, it doesn't"

It is possible to "disprove" a lot of known science with those kind of experiments

Nasa's test and their results are publically available on Nasa's website. http://ntrs.nasa.gov/search.jsp?R=20140009930&hterms=RF+Test...

The article is very sweeping. You're getting only the pro side, not any of the critical view.

People are still heavily debating the experiments. It has not been empirically demonstrated to a standard sufficient to call the thrust real. That's why only a very small community is working on this. "NASA" in this context means EagleWorks is letting a couple people spend a bit of spare time and resources on it as a speculative project.

Mike McCulloch's work is interesting, but it's quite far from any mainstream acceptance or testing, as he himself would admit. It's mostly independent of the EmDrive stuff, but the enthusiast community has latched onto it as a way to escape the unpleasant reality that established physics says the EmDrive is a perpetual motion machine. I'm glad EmDrive is giving his work a boost because I think it should be tested, but there should be much better ways of testing Modified inertia by a Hubble-scale Casimir effect than the EmDrive (he's got a couple blog posts about it if you're curious).

Its arguably a possibility that we are so unsure of the effect because we have scientists "cautiously creeping" so as to not hurt their future reputation.

There was anomalous scaling in the observed effects in one Chinese research teams results, but it has not been repeated because full reproduction and pushing past their power levels would cost some decent money.

Seems stupid the (possibly) most groundbreaking advance in propulsion ever made, can't get a million or two when we collectively gamble more than that each day at casinos lotteries and horses races.

We could quickly eliminate the question of "is this anomalous results from bad experiment design" with a bigger experiment that would make such flaws more evident. Yet we waste time instead of money.

I think you've nailed it there. A professional scientist can't take this seriously because the reputational risk is so high.

Science needs to embrace failure more!

Nobody is allowed to fail or make mistakes any more, not just scientists.

Your past used to fade with time. You used to be able to move town, escape your failure, try again.

Now, any failure is forever emblazoned in shrieking tones online, and the only escape is a new name, and starting over.

It's not just science, it's everything.

Somebody built this complicated device without already having any understanding of how it supposedly works, and you think it might work anyway? Talk about winning the lottery.

What's stupid is betting on stupid.

> What's stupid is betting on stupid.

What's stupid is making investments which are known to have an expected return less than 1:1. Playing the lottery isn't stupid because we don't understand how it works; playing the lottery is stupid because we do understand how it works, we know what the expected return is, and we know that it's a worse investment than just stuffing cash under a matress. This is entirely uncontroversial, and lotteries are run by profit-making entities (either private firms or as a "tax on the ignorant" by governments) whose entire viability relies on this fact.

In contrast, things like the EmDrive are high-risk high-return investments. Their expected return is more difficult to estimate than a lottery, since we'd need to estimate the probability of it working and the expected return if it did work. However, whilst an idea like the EmDrive may be controversial, the idea that spending a small proportion of investment on ideas like the EmDrive isn't controversial. There may be arguments over how much counts as "small", which ideas should be prioritised, etc. but this just goes back to the uncertainty of estimating the expected return. It's entirely uncontroversial to say that, if it works, the EmDrive would be an incredibly lucrative technology; it's also uncontroversial to say that it's unlikely to work. The tricky part is working out which term dominates the expectation: does the big thing (the potential return) multiplied by the small thing (the probability) result in a big thing or a small thing (the expected return)?

This isn't high risk though. It's low risk. However, just because something's low risk doesn't mean it's worth the investment.

The problem here is that you could make this same argument about almost anything, a la Pascal's Wager.

> This isn't high risk though. It's low risk.

I meant "high risk" in the sense that the return has a high variance, with all of it being concentrated in a thin sliver of the probability; apologies if I've misused a technical term.

> The problem here is that you could make this same argument about almost anything, a la Pascal's Wager.

I'd call it a consequence of expected return being a widely-applicable calculation, rather than a "problem" per se. Even if we knew the expected returns, we'd still need a decision procedure to perform the allocation.

My point is that it's uncontroversial to avoid putting all funding into the most promising project (e.g. other Physics research doesn't wait until we're "finished" with the LHC), so there's certainly scope for allocating a small budget to more "fringe" research like the EmDrive. I'm not in charge of research budgets, but as a simplified argument we might imagine allocating funding on an exponential scale, based on expected return and risk: the most promising projects compete for a chunk of half the funds, the "second tier" projects for a quarter, and so on. Projects with lower impact are lower tier, projects with lower probability of success are lower tier. We stop once we've rounded-up an allocation to the smallest unit of funding, hence avoiding Pascal's Wager.

Also note that there are only a finite number of options to choose from, because there are only a finite number of submitted research proposals.

Exactly, in order to have a long career in science, one needs to toe the line, and keep in the mainstream.

>Seems stupid the (possibly) most groundbreaking advance in propulsion ever made, can't get a million or two when we collectively gamble more than that each day at casinos lotteries and horses races.

Perhaps they need to set up a crowdfunding campaign to get those people betting on their experiment, gambling on a science experiment rather than a game of chance.

>only a very small community is working on this

>established physics says

Restricting research capacity and dismissing empirical evidence because it doesn't jive with "established science" is exactly the opposite of what science is all about.

This seems like a misconception to me. Scientists have always tried to apply their energies toward the most promising lines of research. The supply of research capacity is finite.

Can you provide links to alternate timelines that proof your heuristics effective? ;)

Exactly, instead of spending time dismissing the EMDrive as impossible; time should be spent devising experiments that prove it ineffective.

Modern science seems to be rapidly encroaching on religious territory: observable evidence is less important than what historical figures have said.

Science has always had devout, religious elements, don't think otherwise. Look at the backpack the Theory of Evolution received from respected scientists and how much hand-waving dismissal there was of Relativity.

It has been argued that the only way science progresses is when the obstacles to science die of old age.

There have always been the recalcitrant "that's how it's always been done around here" types that often push back even when confronted with evidence. Take, for example, Ignaz Semmelweis[1] - he had the evidence that it works but he couldn't explain how washing hands could decrease mortality in hospitals. Few people took him seriously, he suffered a nervous breakdown and died. Afterwards it took Pasteur and Lister to get people to actually accept the theory.

[1] https://en.wikipedia.org/wiki/Ignaz_Semmelweis

I do understand that it is a recurring theme. This belief approach to science can be scientifically proven to be a bad idea (given evidence such as yours).

While every chance should be made to further explore our current assumptions (such as with the LHC), we shouldn't be neglecting low hanging fruit that challenges our ideas (such as the EMDrive). If as much as 1% of the money that is being spent on LHC went to "anomalous science" we'd likely have a conclusive answer on whether the EMDrive doesn't work. Science is tool that disproves, and we've been hacking it into a proofing tool for far too long. It's time to go back to basics and figure out more about what we don't know.

> McCulloch’s theory makes two testable predictions.

Think about the cost of either of those experiments - vanishing in the face of other science that is being performed today. If science wants to see the EMDrive go away, and is certain that it doesn't work, a comparatively small grant is all that it takes.

We need Antinobel prize for disproving stuff.

A scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it. -- Max Planck

> established physics says the EmDrive is a perpetual motion machine.

In what sense is it a perpetual motion machine? As far as I understand it violates the conservation of momentum, not the conservation of energy. How would a theoretical perpetual motion machine based on this effect work?

Constant thrust means constant acceleration, so speed goes up indefinitely with a constant supply of energy. But kinetic energy is proportional to the speed squared. So you get more energy than you put in.

I don't think they actually claim acceleration will be constant as the devices accelerates up.

It only looks like conservation of momentum is violated. From the article:

>The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust.

The new idea introduced is the quantization of inertia at small accelerations. As far as I understand it, from one end of the cone to the other there isn't a smooth change of inertia. This depends on the idea of Unruh radiation, and the reason the article gives for quantization of inertia is that as accelerations get very small, Unruh radiation wavelength becomes larger than the observable universe, forcing unruh radiation to take whole-value wavelengths (quantization). Again as far as I understand it, the inertia of photons on one end of the cone takes a different quantized value of inertia than the photons on the other end. So the thrust isn't a violation of conservation of momentum. The thrust is necessary to not violate conservation of momentum.

No, the new idea is a massive photon. There's strong limits on that from astronomical observations, and a stronger one from Special Relativity when cast in a modern isometry group theory form. In that form, the Poincare Group is the isometry group of the unremovable (flat space) background, and the Poincare Group has exactly one free parameter, "c", which corresponds to the speed of a massless particle. In this form, we assume that light is massless, and look for experimental evidence supporting that assumption (there is a fair amount; we have lab studies showing that the m_photon cannot be more than about 10^-17 eV/c^2 and there are even more stringent limits from observational cosmology).

A nonzero photon mass makes a mess of particle physics at high energies. The Standard Model falls apart due to loss of gauge invariance, and QED becomes really obviously non-renormalizable near limits we have already tested. So this would be a big thing.

(Note that if you bite the bullet and take a nonzero photon mass (as McCullogh says in his paper at page 3: "Normally, of course, photons are not supposed to have inertial mass in this way, but here this is assumed") you can probably get a non-constant photon speed too, along the lines of neutrino oscillation. But you can always write down non-physical theories that conflict with frequently and precisely tested areas of physics...)

None of the above departs from the symmetries of Special Relativity, and one subgroup of those (invariance under spatial translation) is what implies the (local) conservation of (linear) momentum per Noether's (first) theorem.

So there's a really big looming question about why the Standard Model (which has the Poincare Group baked into it) works as well as it does everywhere but in an EmDrive or a single space probe, and resorting to special shapes of objects on scales much larger than that of atoms further conflicts with Poincare invariance.

Finally, Unruh radiation is a difference in particle count and particle energy measured by differently accelerated observers. The cosmological horizon, when it formed, produced an acceleration between observers then and observers in the future. Unruh radiation from that is pretty uncontroversial. However the problem is that the acceleration is pretty small, so the temperature will be much lower than that of the CMB. Also, you'd expect anisotropies based on Earth's (and its surrounding Local Group's) peculiar motions relative to the horizon. Why isn't there a dipole anisotropy similar to the one we see in the CMB, and if there is, by how much does it offset the inertial argument in McCulloch's paper?

Conservation laws aren't fundamental, but are implications of local differentiable physical symmetries (this is the primary result of Noether's (first) theorem).

The local symmetries in question are represented by the Poincare Group, which is the isometry group of Minkowski spacetime, which in turn is the unremovable background of Special Relativity. (The Lorentz Group is a subgroup of the Poincare Group).

This is another way of saying that in a 3+1 flat spacetime, well-designed local probes of fundamental physics will not depend on time translation (i.e., experimenting today vs experimenting tomorrow), on spatial translation (e.g., the same experimental results here vs there), on spatial orientation (i.e., rotation about the 3 spacelike axes; so you get the same result when you turn the system under test 90 degrees to the left), or under Lorentz boosts, which are basically instantaneous changes in constant uniform motion along any of the axes. Additionally, small-scale (small compared to several times the size and mass-energy of the whole solar system) natural phenomena are essentially always "well-designed local probes of fundamental physics".

Conservation of linear momentum arises from invariance under spacelike translation; a violation of that conservation makes it very difficult to maintain spatial translation symmetry, and in particular flies in the face of the many direct tests of physical systems at different places on our planet and in our solar system, for example. So that's a big deal that needs explaining, and in particular the explanation should preserve the known and reproducible invariance under those translations as well as allowing the EmDrive's alleged violation.

The perpetual motion machine argument is slightly different because it is rooted in a claim about how the EmDrive behaves when in non-constant motion; in the current version of the theory paper "V 9.4" at equations 14-16, there is an implied violation of the Einstein Equivalence Principle. The equation is a bit odd, and you easily can read it to say that there is a power<>thrust relationship that varies with acceleration, and raise the Einstein elevator objection: if you put the EmDrive into an upwards-accelerating box, or leave it on the ground, do you still take this power<>thrust relationship seriously? If so, you get "free power" (although that's a bit subtle). If not, then you have to explain a violation of the Equivalence Principle, which is also something that has also been very well tested and has so far applied without fail.

You could think of it with a somewhat concrete example: to hover at some fixed height above the Earth's surface, the EmDrive would have to emit thrust similar to the amount of work you would do to hold it at that height with your hands; since you are near the surface, that should be about "g" expressed as N/kg (and indeed Eq 16 tells you how much electrical power you will require for the EmDrive). So far so good. But (eq 16) can be read to say that when you place the EmDrive on the ground, it will produce electrical power proportional to to "g".

I think this is pretty clearly just a mistake rather than a serious claim. Unfortunately eq 16 features prominently in the FAQ and all the "marketing" material about the EmDrive. (Even more unfortunately it's hard to see how to fix the equation without making the drive obviously inoperable).

Thanks. For the supposed violations - aren't we still then only discussing the device working within known physics? There is no violation if the device were to slowly lose mass due to some unknown process (making it a form of Ion thruster), or if it accelerates some yet unknown weakly interacting massive particle in the opposite direction of the thrust, or if it somehow only conserves invariants for a "larger" system, potentially the entire universe?

Given an exotic enough explanation (negative energies/faster than light particles/spacetime warping/..) it feels like you can cheat your way around almost any invariant? Occam is left weeping in a corner of course.

Sure, if it's not actually reactionless, most objections fall away.

The problem with reaching for exotic particles or the like is that we don't see them in searches which involve tens of orders of magnitude more power, and we certainly don't see them in, for example, electric toasters or radar sets. So what would need explaining is what's peculiar about the EmDrive with respect to (extremely) unusual particle interactions, and there is [a] nothing obvious and [b] nothing at all in the "theory" paper.

Likewise, reaching for non-local physics answers raises similar questions (why is EmDrive doing non-local whatever but my kettle isn't; or alternatively, why is EmDrive coupling with whatever much much much more strongly than my conventional oven is).

I have another pair of things that you can add to the list: [a] EmDrive somehow violates causality in a way that other similar arrangements of mass-energy-momentum does not and [b] EmDrive somehow escapes logic in a way that other similar systems under study does not. These are neither more far-fetched nor more unpalatable, compared to abandoning local physics (causality and logic preserved, but hidden non local variables proliferate) or abandoning the Standard Model as an accurate low-energy theory of matter (causality, logic and locality preserved, but now what happens in the molecules and atoms of cars, computer chips, and light bulbs? we no longer can be quite so sure!).

There is A LOT of known physics and almost exactly zero examples of violations of the known invariants at low particle energies. You are re-testing relevant parts of all that in reading this comment.

That's not the case. Tajmar did one in vacuum. http://www.ibtimes.co.uk/emdrive-dr-martin-tajmar-generates-...

They did it last year and alo found some thrust signals, altough they were very careful to leave the door open to measurement errors, like Lorentz forces.

Eagleworls lab will also attemp one vacuum test in a more equipped NASA lab.

I tend to think it's all vapourware since it goes against so many well founded rules that it's more likely that it's just pathological science. The theory in the OP is also likely to be rubbish. The author of the paper was challenged many times and failed to provide sound answers. Furthermore he supports a telepathy "researcher" which is also a red flag.

Because we should only research orthodox, approved subjects, and not go where the data leads us?

You're seriously suggesting that his mathematics should be studied less seriously because he has a friend who studies telepathy?

Well, it's not just a friend, it's something he supports.

There's something to be said for Bayesian updating, and in this case I'm willing to say that people who have the right of it scientifically are less likely to support telepathy.

I haven't read any previous studies of telepathy, so I have no informed opinion on it. Which seems to be a minority position: the majority position seems to be to assume that not only is telepathy "not real" but also anyone studying it is clearly a "not real" scientist.

Is there any data to support your theory that people who are willing to study telepathy are less mathematically able than those who are not?

Because it seems to me that people who are willing to rule out an entire area of study for social reasons are less able scientists than those who are willing to go where the data leads regardless of reputational consequences.

This EM drive is a case in point. Studies seem to suggest there is a real thing happening here, but scientists are not willing to study it because of the reputational risk. Which is clearly bad science.

You keep saying "go where the data leads" but the data is leading in circles so far. What data would lead you to study telepathy? There's data then there's wishful thinking.

I am sorry, but nerve system is electric. It emits electromagnetic signals. Nerve system is also perfect receiver for these signals. If you will train your body to emit/recognize these signals, you will be able to communicate telepathically. Your "hardware" (bioware?) allows you to do that. Some sharks are using that skill to locate fish.

Not sure if troll or serious.

Go ahead and try that and get back to us.

And it's been done[1], successfully — but the signals need to be amplified before the receiving brain can detect them. Parapsychology research was answering a pressing need in the 1950s, and so it was pursued and funded. Now that we have ubiquitous resilient encrypted wireless broadband communication on the worldwide scale, and we're pretty sure the enemy forces cannot submit our soldiers using the power of concentration, the need is much less pressing. Recent advances in brain activity imaging with fMRI and the impetus to create computer-brain interfaces will lead to any advances in telepathy that can be had, and maybe discover new questions to study.

Out of all the futures that seemed possible at the beginning of the Cold War, ours is no less strange and awesome than one where telepathy were a mundane experience. Being skeptical about telepathy in the style of the great Sci Fi works of the latter half of the 20th century reflects the understanding that some ideas become reality, and some just peter out.

[1] http://www.kurzweilai.net/first-brain-to-brain-telepathy-com...

Body can be trained to improve strength of signal and make it directional.

I tried to train myself to improve strength of my look few years ago by training, and girls describe their feeling at that period as "burning skin". When I looking at them with concentration, they able to feel that at distance of up to hundred of meters. I also saw video with similar experiment recently, but I cannot find it right now.

So, IMHO, telepathy is possible physically at some short distance, but requires years of training of participants. Someone need to train himself to be strong signal emitter, which can be confirmed by measurement of body EM radiation at frequency interval of 1.3-30Hz. Then somebody else need to learn how to hear that weak EM signal, like blinds do.

If what you're saying were true (even requiring decades of training), it would herald a revolution in our understanding of human physiology. Let's see you reproduce these experiments in a lab with a skeptical researcher.

Where I can get funding to research short-range telepathy and other mumbo-yumbo science? :-) I was very skeptical myself just few years ago.

I had similar feeling ("burning skin") only two times in my whole life, so, IMHO, it is very rare. However, woman told me that it is no so rare, and staring of some "hungry" mans is similar. IMHO, it is sort of "I love you", but for silent animals.

> Where I can get funding to research short-range telepathy

DARPA[0].

This kind of research really has been done to death, and much of the groundbreaking research has been declassified by now. For example the CIA mind control research[1].

[0] http://www.darpa.mil/news-events/2015-01-19 [1] http://www.theblackvault.com/documentarchive/cia-mkultra-col...

Tell us more?

It's like hearing. I can hear, but I cannot explain - how. My English vocabulary is not enough to describe it in details (I am from Ukraine, I learned English as adult).

Before that, I used some techniques to better control my body and feelings for years, so I was able to notice subtle differences and gradations of my feelings. I also know (poorly) body language (because I am amateur ballroom dancer), so I can notice subtle changes in behavior of others.

I feel warmth at my face when I do that, like warmth after warmup, and not like warmth when I self-heat a part of my body by concentrating at it.

It is much easier to stare at somebody, if I have feelings to her/him (e.g. when I like or dislike her/him).

It works without eye contact: from target back or when target is sleeping.

Targets always know direction from which I stared at them.

When effect is strong, it is easy notice it: it feels like something happens at skin ("burning") but without pain of any kind, i.e. nerve system sends strong signals about something ephemeral, but nothing happens in reality. When effect is weak, it feels like warmth, so it is easy to mismatch it with self-heating with concentration. So, to test effect properly, you must not say to targets that you testing them, otherwise they will concentrate at their body and will feel warmth.

IMHO, it is kind of "i like you/i dislike you" sign language used by animals and then forgotten by humans.

I had similar feeling myself, but two times only:

- in train, from girl: after about hour of staring at her (experimenting) I got exact same response. :-)

- from soldier, when we talked about how to free Crimea of Russian soldiers. :-)

It is all.

I stopped doing that because it was hard to stop looking without staring. Random people started to like me for no reason, remember me and my name for years, etc. I unlike that.

PS. I saw a film where I was able to track at which girl operator/director is looking when filming, because of girl reactions, so I am 100% sure that I am not alone. :-)

You trained your telepathy by staring at girls? And then asked them how they experienced it?

I'm not convinced that this is a valid experimental procedure...

It is not a telepathy, it is something else. But yes, I trained myself by staring at girls from their back and noticing how they react, and what I feel, when they react.

This is not a valid experimental procedure, of course. I saw video with experiment which was done properly, but I cannot find it.

I have a good news for you, if you are not sitting on millions already, here's an easy way:

http://web.randi.org/the-million-dollar-challenge.html

Wow, did you even bother to follow that link?

To be fair, that link did work for a good many years.

I didn't know that Randi had retired and that the prize had been withdrawn. Very sad. It's the end of an era.

Thanks, actually no. I've linked it many times before, assumed it's still the same.

I wasn't suggesting that the data leads to telepathy. It may, it may not. I don't know. I haven't studied it. But dismissing anyone that studies it as a crank, and by implication anyone that supports them in that study as also a crank, is bad for all of us.

I'm less concerned about telepathy per se than with "science as politics". The social sciences are seeing some serious problems because there are things that scientists cannot say or talk about because of their political implications. Climate science is hampered by the problem of having to be constantly aware of the political ramifications of their research: are they "helping the deniers" if they publish a result?

If we start bringing this bullshit into hard science then we'll break that too. This is maths and physics. There's the hypothesis, there's the experiment. Do the experiment and validate the hypothesis. If the experiment isn't working, devise a better one. If the new theory leads to predictions then test those predictions. It's all objective, it can be tested, and those tests can be reproduced.

It's like free speech. I may not like the things you say, but I will absolutely support your right to say them. If you find telepathy interesting enough to study, then that's awesome. If you think you've got a result, and I'm interested enough, then I'll look at your methods and your data and work out if I agree with you or not. But dismissing you as a crank just because you're studying it is anti-scientific.

And just like free speech is being threatened by politics and there are now things that people must not say, science is becoming threatened and there are things that must not be published. This is bad imho.

If you're interested, then go ahead and read about the history of telepathy research so you can have a (more) informed opinion about it. Numerous well-performed and controlled experiments have not find any evidence for it, and in this case, absence of evidence is reasonably strong evidence of absence. Since there are so many other interesting (real) things in the universe to study, I conclude that people who continue to study it are doing so for reasons unrelated to the merits. It doesn't make someone "not a real scientist", but I sure would look askance at their critical thinking skills.

> This EM drive is a case in point. Studies seem to suggest there is a real thing happening here ...

That's not what I see. Every time the experiment is done with more precision and less noise, the effect diminishes again to near the limits of experimental error. That's exactly what you would see if the force was due to thermal (or other electromagnetic) effects rather than novel engineering principles. Nothing wrong with studying it, though. But I'd be willing to bet real money it all comes to nothing.

Edit:

> Is there any data to support your theory that people who are willing to study telepathy are less mathematically able than those who are not?

No, of course there is no such data. And mathematical ability is only tangentially related to critical thinking in the real world.

> Because we should only research orthodox, approved subjects, and not go where the data leads us?

Data is crappy at the moment, but I agree, it's at least interesting in the case of the EmDrive that people are measuring something.

-- Actually yes, if somebody follows crank science my trust factor goes down (the Mariana trench). But that's me, if you see no problem with it, just study his paper. He also a big opponent of dark matter. But hey, I'm just a programmer, what do I know about theoretical physics.

Read this thread:

https://www.reddit.com/r/EmDrive/comments/3hjmtv/my_conversa...

The guy who challenges him is a PHD student who happen to be usually on the right side of theories although sometimes being too hard headed.

Measurement error is a fine, and even necessary hypothesis in attempting to explain the observed effect. Multiple, independent replications tend to cast doubt on the ultimate viability of that hypothesis, however. How likely is it that all of these people at all of these labs are making the same measurement error?

And then, on top of that, when the observed effect comports with a theory that also predicts another, well-established observed effect?

It's been said that the most important phrase you will ever hear a scientist utter isn't, "I've found it!", but rather, "Well, that's strange."

This is very much in the, "Well, that's strange" class of things. Either way, we're going to learn something about how the universe works, or about our ability to measure it, or both. This should be celebrated, not dismissed as mere "measurement error."

The existence of the Unruh effect in it self is currently quite debatable. https://en.wikipedia.org/wiki/Unruh_effect

You'll note that I didn't actually assert the existence of the effect. I observed that a theory which predicts the effect the EmDrive appears to demonstrate, also predicts the fly-by anomaly, and offers a unified explanation for both.

Yes, it requires more confirmation. Much more. I'm not a scientist, but I think that, taken together, it's interesting enough — "Well, that's strange" enough — to warrant further investigation, instead of being all, "Meh. Measurement error."

Am I mistaken in that belief?

It's worth an investigation because it can be done cheaply and there might be something there. We've also investigated ESP and quite a few other weird things.

Unruh radiation is weird under some interpretations it can be used to reduce the inertial mass of objects, the thing I take from this is that I hope the EM drive could prove it rather than the other way around because then we might say we've discovered the "Mass Effect" ;)

It's also quite possible that the theory was derived to fit these observations. This theory has yet to predict anything new that has been proven. Until it does it only amounts to a possible way of connecting two unexplained and possibly flawed observations.

People noticed an effect every time the Dean Drive was turned on... but it is just a stiction engine and obviously won't work in space. It could be this drive is actually generating magnetic forces or moving air around and thus "creating thrust" by pushing off its surroundings, which won't work in a vacuum.

... which was already tested for. vacuum or not seems to make no difference on the effect.

It could also push off the Earth magnetic field.

Then it should depend on the orientation (and altitude, geographical location). According to [1] this was tested for.

[1] http://emdrive.com/faq.html

Well I guess the ultimate test would be to put the whole contraption in space, turn it on and see if it moves. Then it would be undebatable, no?

> The obvious explanation is that they have an error in the measurement.

Then why have 6 different teams verified it? Not saying EmDrive is the real deal but either the error is hard enough to catch 6 teams missed it, or theres something else going on. Saying all these teams are wrong, to me, is far from "obvious".

Obvious explanation, not only explanation.

Would it really be do surprising if similar experiments all working from the same basic design using similar components under similar conditions suffered from the same design flaw?

Do you have a link to the 6 experiments? I'd like to compare the results. This link has a list of 3 or 4 experiments before December 2014, that is more than 1 year ago. http://forum.nasaspaceflight.com/index.php?topic=36313.msg13... I'd like to compare that with the new results.

With the "current" physic laws, the theoretical maximum of ForcePerPowerInput is 1/c = 0.0033 mN/kW. In that table, the ForcePerPowerInput varies from 300000x to 3x. That's a lot of variation, not and exact value that coincides with a theoretical prediction. It's a pity that the list is not ordered by date.

If you order the experiments by date and all of them have roughly the same result, they probably are measuring a well known effect were all the variables are well understood. Like measuring g with a pendulum.

If you order the experiments by date and the value increase a lot, it's perhaps a new phenomena that is still not well understood and they are tweaking the materials to get more efficiency. For example, let's consider measuring the critical temperature of a high temperature superconductor. If you pick a fixed simple superconductor, you expect to get approximately the same result in any laboratory, but small changes in the fabrication process can increase or decrease the temperature. But any time someone discover a new superconductor material or method of production, you will get a new record, so the world record will increase and the other laboratories will try to reproduce and increase it.

If you order the experiments by date and the value decrease a lot, it's possible a sign that they are fixing some experiential details and reducing the experimental errors, and they get a smaller result because the correct value is 0.

Yeah imagine if someone had made similarly exciting claims about an unexpected and so-far impossible-sounding wrinkle in how gcc works. A bunch of people tested gcc and got all different results. Nobody cites any of the results or discusses any detail.

Everyone would be asking to see the code and the output for themselves before they got excited.

Wikipedia says that the experimental tests disagree on even the sign of the measured force:

"An article published by Shawyer in Acta Astronautica summarises the existing tests on the EmDrive. Of seven tests, four produced a measured force in the intended direction, and three produced thrust in the opposite direction. Furthermore, in one of the tests, thrust could be produced in either direction by varying the spring constants in the measuring apparatus. Shawyer argues that the thrust measured in the opposite direction is the reaction force from the drive, and therefore it is consistent with Newtonian mechanics.[1]"

https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster#St...

One thing to note though I'd that the theory of the OP could actually explain that sign shift.

Another way to explain the sign shift, though, is that the thrust might be zero and experimental errors come out both positive and negative.

Wasn't there a problem that while there was an anomaly of some sorts, different teams still reported significantly different results? That would still mean that n-1 teams were wrong, which could mean that the nth team could have been wrong as well. Or was that some other similar device?

I didn't read through all the papers, but didn't the testing labs measure the weight of the apparatus precisely before and after? If it's any mass being vented off, I assume this would show up, and you can make precise predictions about how much mass would be needed by calculating upper limits for the velocities these particles could be accelerated to.

So your counter argument should be pretty easy to test, and I'd be surprised if this isn't accounted for in these experiments.

In the example of FTL neutrinos there was only one non repeatable instance - here we have at least three.

Most of the times skepticism is good, but sometimes it can blind you - at the very least this effect needs to be investigated further because the implications - if it turns out correct - to both practical applications and physical theory - could be huge.

Not a good comparison, considering six independent research bodies including NASA have experimentally verified that this does work (citing the OP article)

They have verified that there is an effect that needs explaining. Claiming that 'it works' is just as premature as claiming that it definitely doesn't.

The article isn't necessarily truthful.

It's still well within the realm of measurement error.

> The article isn't necessarily truthful.

Speak plainly. If you're going to assert the article is false, assert that it is false.

He's asserting the article might be false, not that it is false.

TIL I learned that Flogisto is more than a spacejammer thing.

Presumably GP meant phlogiston https://en.wikipedia.org/wiki/Phlogiston_theory

And presumably your parent meant Spelljammer. https://en.wikipedia.org/wiki/Spelljammer

Oops. Indeed. I messed up my spelling.

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