Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Bobboau on July 27, 2015, 02:48:18 pm
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https://hacked.com/scientists-confirm-impossible-em-drive-propulsion/
:nervous:
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You know, I do love that quote from Wired at the end.
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I love the fact that there is an offshoot to it called the 'Cannae Drive' - http://cannae.com/
Scotlands going to love that one...
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The smart money is still on a measurement artifact. (I'm guessing thermal...?)
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White proposes that the EM Drive’s thrust is due to virtual particles in the quantum vacuum that behave like propellant ions in magneto-hydrodynamical propulsion systems, extracting "fuel" from the very fabric of space-time
I for one am deeply concerned about the potential for abuse by Big Propulsion. The fabric of space-time is a nonrenewable resource. We all need to do our part to conserve energy and momentum so that reality will continue to exist for our children and grandchildren.
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The smart money is still on a measurement artifact. (I'm guessing thermal...?)
I'm convinced that we all want it to work so much, that our collective will is bending reality and causing it to work.
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The smart money is still on a measurement artifact. (I'm guessing thermal...?)
The "smart money" on that has turned out to be fools money quite some time ago, just so you know. Thermal has been ruled out. Experimental error is highly unlikely, unless it's some sort of complex interference with measuring equipment (that would be itself very interesting). As far as I'm concerned, it's either an unknown source of error or an unknown source of thrust. Either way, it is a breakthrough, either for spaceflight or for measuring equipment design. :) The article sounds like they have yet to eliminate some possible causes of magnetic interference, but somehow I don't think that'll be it.
As it stands, all bets are off with regards to what it's actually doing. But we do know for certain that it is doing something. Indeed, the only reason I'm currently going into condensed matter physics instead of this is that our institute isn't doing anything related to the EM drive (totally not because I'll be able to tell people I work with a particle accelerator in a year or two if this works out :) ).
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Thermal hasn't been ruled out. You're thinking of thermal convection effects inside the cavity.
The fact that thrust continues even when the power's turned off is pretty suggestive of test error.
Remember, guys, wanting something to work (I do!) is not reason to update all your hypotheses in favor. There's a lot more work to do before this looks viable.
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It ultimately comes down to one thing: someone will have to strap this thing to a rocket and go around the moon or something. Until that's done, I will continue to be skeptical of this.
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Remember, guys, wanting something to work (I do!) is not reason to update all your hypotheses in favor.
It's actually a reason to be even more skeptical about it.
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Science was borne out of skepticism. :p
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Extraordinary claims require extraordinary evidence. Of course EM drive development should be pursued, but personally I will believe it when I see it propelling a satellite, not before.
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White proposes that the EM Drive’s thrust is due to virtual particles in the quantum vacuum that behave like propellant ions in magneto-hydrodynamical propulsion systems, extracting "fuel" from the very fabric of space-time
I for one am deeply concerned about the potential for abuse by Big Propulsion. The fabric of space-time is a nonrenewable resource. We all need to do our part to conserve energy and momentum so that reality will continue to exist for our children and grandchildren.
I say the same thing about oil and gas!
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It ultimately comes down to one thing: someone will have to strap this thing to a rocket and go around the moon or something. Until that's done, I will continue to be skeptical of this.
I dont have the technical knowledge to even try to understand what should or should not be possible but this is the kind of thing that would settle things one way or another. do this and then figure out the science behind it, I think it's time the moon got probed again.
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with the buzz floating around this thing, it seems it should be trivial to build one, launch it into space, turn it on, and see what happens to it's orbit. a million dollars and this thing is settled.
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with the buzz floating around this thing, it seems it should be trivial to build one, launch it into space, turn it on, and see what happens to it's orbit. a million dollars and this thing is settled.
isnt this the kind of crazy thing that NASA, ESA and the likes was set up for in the first place? prove it can be done and then let private enterprise make money from it.
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Extraordinary claims require extraordinary evidence. Of course EM drive development should be pursued, but personally I will believe it when I see it propelling a satellite, not before.
Well, so far the evidence was nothing short of extraordinary. :) It is being still checked for errors (as any extraordinary claims have to be), but this time, we haven't yet heard about any "loose cables", so to speak. Also, spacecraft propulsion might turn out to be one of the less important implications of the discovery. It interacted with White's warp field spectrometer in a rather interesting way (I believe there was a thread about this when it happened).
Thermal hasn't been ruled out. You're thinking of thermal convection effects inside the cavity.
The fact that thrust continues even when the power's turned off is pretty suggestive of test error.
Remember, guys, wanting something to work (I do!) is not reason to update all your hypotheses in favor. There's a lot more work to do before this looks viable.
Thermal effects in general has been extensively ruled out. People suggest them from time to time, but they were the first thing they checked. They tested the drive in vacuum, so no convection of any sort. I think that thermionic emission and thermal photons were ruled out as well (besides, if it worked based on that, it'd make it one mighty ion engine). I don't think that heating up the scale would cause it to indicate thrust (or that they would've missed an effect like that). "Thermal" is a pretty wide term, but since there was a positive vacuum test, it leaves you with relatively few options. All of them would be exciting in their own right, BTW, since the indicated thrust is far more than ion and electrothermal engines currently in use.
Thrust persisting after power is turned off might also indicate that the effect involves hysteresis curve somewhere. Like with capacitors charging, the energy already pumped in may take a while to dissipate. Or it might be an indication of magnetism screwing the result up (because it's an effect they're not certain about that has a hysteresis curve). BTW, where is that info from? I haven't seen anything about thrust persisting when the power is off. This is not necessarily a cause for alarm, unless they still get positive thrust when they go back to the lab the next day. :) I find skepticism becoming harder and harder. Unless they find something in the magnets (which they may), it really is going to shake up physics. And even if they do, we'll know more, since the "obvious" errors were all ruled out, so something unusual is going on. Granted, the case of an "interesting error" is less exciting to an average person, but it'd have its uses as well.
Skepticism is fine, but sometimes it results in discarding potential discoveries. In general, it often occurs that once a constant has been measured wrong, the value will "drift" over to the correct one over time. The reason is, the next team determining it will often find the earlier paper, find their own results (even if they're correct) not matching it and continue messing with their equipment and cherry-picking data until they kinda-sorta match the old value. The next team does the same, except referencing the previous teams' value (closer to truth, but still wrong) and so on, until they zero in on the right one, which may take years. Too much skepticism with regards to your own results might cause experimental discoveries to be delayed greatly, especially if there doesn't exist a theory that would predict them.
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In the end it comes down to what The E said: there's no point saying 'yay it works' until someone has the damn thing in orbit, measurably increasing its momentum.
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I think what Dragon is saying is "Yay, we're about to understand that we don't understand something, and then try to understand it." Which is pretty cool.
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Right now the probable outcome is 'test error,' which is of no use to anyone. Keep an eye on the replications and the peer critics. That's how we'll tell if this is real.
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identifying a less obvious form of systemic error and making people more aware of it is useless?
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Well it's not nearly as useful as a reactionless drive.
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that's true, but it has a value that is above zero.
also demonstrating that science is open-minded has value. when there is evidence of something that everything we know says should be impossible, not dismissing it, has value. Even if you know it's not going to go anywhere, letting it fall flat on it's face, very publicly, is much better than just saying it's impossible because it breaks the rules.
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I think Science suffers a little from what I call the 'cold fusion' problem, in other words, claiming a discovery that turns out, on inspection, to be false can effectively be the end of your scientific career and it shouldn't be really (though, there were other aspects involved in the Cold Fusion case). The whole point of Science is to observe a phenomena, postulate a theory and then test the theory and find out which bit you were inevitably wrong about.
As has been said, the best way to test it is to stick it onto a little probe or something and send it into orbit, but that won't happen because if it doesn't work, the media doesn't really have the understanding of scientific principal to see it as anything other than 'NASA spends $ on experiment that doesn't work.', you're unlikely to see the caveat 'but we learned quite a lot from it anyway' until you are quite distant from the headline itself.
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Quick, someone go get Elon Musk interested enough to put this on a probe and send it up on one of his rockets and test it.
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Can't do more than wait and see :). And the "wait" part might take years, decades. So yeah. :/
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I think this will be resolved in 2-3 years.
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Yeah, I'm with the "proof is in the pudding" school on this. Build one, stick it on a chunk of metal and ceramic in orbit, set it toward the moon, and see what happens.
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I really am sort of shocked we haven't had an eccentric billionaire throw a few of these things into space.
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There's a reason they are billionaires. They're probably waiting for 1) a few more tests, and 2) a way to make some profit on this (unless they're an altruistic billionaire).
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there is a reason I threw that "eccentric" qualifier in there.
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Right now the probable outcome is 'test error,' which is of no use to anyone.
Except for scientists working on warp fields, hyper-precise force measurements (you'd be surprised how important it is) and theoretical physics. We've reached a point at which any results brings us something new and exciting in its own way. A failure we can learn from can be just as valuable as a success, at least after you've ruled out trivial stuff like "Duh, that stupid cable was loose". If you only want knowledge, there's no way to fail when practicing science (unless you let your own bias ruin your results, or maybe have a major equipment failure). Of course, the general public, businesses and people who hand out grants would usually rather have something at least potentially practical come out of the research.
I think Science suffers a little from what I call the 'cold fusion' problem, in other words, claiming a discovery that turns out, on inspection, to be false can effectively be the end of your scientific career and it shouldn't be really (though, there were other aspects involved in the Cold Fusion case). The whole point of Science is to observe a phenomena, postulate a theory and then test the theory and find out which bit you were inevitably wrong about.
Well, actually, I think that this is a good safeguard against sensationalist "discoveries" that have not been extensively tested. There are many things which can go wrong if you're not skeptical enough. Cold Fusion was such a case, FTL neutrinos also had shades of it (though admittedly, mostly courtesy of the press, I don't think anybody lost a job over that except the poor technician directly responsible for the mess). On the other hand, too much skepticism is also harmful, because it may lead to dismissing extraordinary results out of hand. The Chinese team that tested EM Drive before NASA should've been given more credit, for example. One needs to find a happy medium.
As for sending an EM Drive into space, I think it'd be a bit pointless. The measured thrust is small and the power requirements quite large. Not to mention that without knowing how it works, it's difficult to come up with a preparation procedure for launch. Space is a very hostile, very difficult environment with many variables, many of which could affect the drive. We know it works in vacuum, but engineering a satellite to carry it would be a challenge. You'd have to give it auxiliary propulsion (just in case the drive doesn't work), large solar panels, probably a high-tech bus with lots of measuring equipment... Oh, and lots of paperwork. And money. It's hardly ready for use on spacecraft. It's easier and cheaper to just test on the ground. Really, the implications are interesting enough even if it can't be used as a space drive for whatever reason. Oh, and from a technical standpoint, space makes it harder to detect micro accelerations, not easier (despite how counter-intuitive it might seem).
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there is a reason I threw that "eccentric" qualifier in there.
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Shawyer's research is now peer-reviewed and published in Acta Astronautica.
https://hacked.com/emgate-wars-continue-publication-peer-reviewed-emdrive-paper/
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we're calling this "EMgate" now? :doubt:
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I strongly desire to go back in time and swipe the second half of the Watergate complex's sign so that every goddamn thing for the next 50 years stops using that asinine suffix.
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You know what I find most laughable about this? Every single press release seems to be using a gridded electrostatic xenon thruster pictures when talking about the EM drive. :) You know, the ring that emits blue-ish haze, with a small neutralizer hole (or several) in the center. This is a regular ion drive, flown multiple times and about as mysterious as a normal chemical rocket engine. It looks (and works) nothing like the EM drive. EM drive looks like this:
(http://blogs-images.forbes.com/ethansiegel/files/2015/05/em-drive.jpg)
And doesn't emit any haze at any time (if it doesn't use reaction mass, there's nothing glowy being thrown out, it stands to reason). I noticed that even the thread title likely refers to gridded thruster pics as well.
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yup it was :)
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EM drive looks like this:
(http://blogs-images.forbes.com/ethansiegel/files/2015/05/em-drive.jpg)
And doesn't emit any haze at any time (if it doesn't use reaction mass, there's nothing glowy being thrown out, it stands to reason). I noticed that even the thread title likely refers to gridded thruster pics as well.
I get there's no glowy haze, is there any type of visible indication it's running at all? Just curious.
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I strongly desire to go back in time and swipe the second half of the Watergate complex's sign so that every goddamn thing for the next 50 years stops using that asinine suffix.
Or cause a new scandal at the same place so that they have to start calling it Watergategate.
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well, when it goes flying off at relativistic speeds the moment you turn the power on, you could consider that something of an indicator that it's working, and I would imagine that it might glow red due to heat from all those microwaves bouncing around.
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Nah, that's just a thermal effect. :P
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well, when it goes flying off at relativistic speeds the moment you turn the power on, you could consider that something of an indicator that it's working, and I would imagine that it might glow red due to heat from all those microwaves bouncing around.
except that with the amount of thrust that it's getting, it's not going to be doing that. Also it appears that the magnetron is the one that's warming up, not necessarily the resonating cavity. My rudimentary knowledge of how waveguides work tells me that it isn't tuned/positioned correctly, so most of the power is being reflected back into the magnetron rather than trying to bounce around in the cavity.
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You know what I find most laughable about this? Every single press release seems to be using a gridded electrostatic xenon thruster pictures when talking about the EM drive. :) You know, the ring that emits blue-ish haze, with a small neutralizer hole (or several) in the center. This is a regular ion drive, flown multiple times and about as mysterious as a normal chemical rocket engine. It looks (and works) nothing like the EM drive. EM drive looks like this:
(http://blogs-images.forbes.com/ethansiegel/files/2015/05/em-drive.jpg)
And doesn't emit any haze at any time (if it doesn't use reaction mass, there's nothing glowy being thrown out, it stands to reason). I noticed that even the thread title likely refers to gridded thruster pics as well.
It still looks really cool, in a steampunk-ish kind of way.
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It still looks really cool, in a steampunk-ish kind of way.
Nah, it's just retro:
Apollo F1:
(http://media.al.com/breaking/photo/f1-engine-cc122e98a7ceb399.jpg)
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except that with the amount of thrust that it's getting, it's not going to be doing that.
(https://i.imgur.com/U7Ghu2sh.jpg)
:blah:
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Hey don't blame me, you forgot your sarcasm tags and/or this guy: :P
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I think just most media-type people were expecting (and asking for) something that looks like it's out of Star Trek, not something out of Jules Verne.
Jules Verne-looking engine is cool, though.