• Nasa validates 'impossible' reactionless space drive [Wired]
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There's hardly a single ounce of anything even approaching "cautious" in the thread.
[QUOTE=Intoxicated Spy;45562852]Rather have him rain on it, then hoping for something that never comes.[/QUOTE] I remember reading that the recreated drive produced only a fraction of the thrust that the Chinese group claimed, having a 'positive' result as claimed in the article might not mean much.
[QUOTE=Bradyns;45562772]JohnnyMo1, we need you to legitimize, or dismiss these claims![/QUOTE] remain skeptical
[QUOTE=Swebonny;45562735]Yeah more or less. If it's true it's change a lot of things. Like... HOVERBOARDS.[/QUOTE] Holy fuck. [img]http://www.scifinow.co.uk/wp-content/uploads/2012/12/Mattel-hoverboard-Back-To-The-Future.jpg[/img]
[url]http://www.reddit.com/r/Physics/comments/2c96ls/emdrive_tested_by_nasa/[/url] The /r/physics thread has a good amount of healthy skepticism as well as coherent reasons to not get excited: 1. The guy who wrote the theory paper is terrible. Plenty of outright falsehoods and poor review. 2. Very small thrust produced, so susceptible to experimental error. 3. Unequivocal violation of conservation of momentum, which is well-tested.
[QUOTE=JohnnyMo1;45563634]remain skeptical[/QUOTE] You can say that about (almost) anything and it would be good advice :v:
[QUOTE=Mbbird;45563576]There's hardly a single ounce of anything even approaching "cautious" in the thread.[/QUOTE] Par for the course for FP and anything that gives them hope that their life will be a sci-fi one day.
Meh. I had hoped like a cooler name like "Mass Effect Field", but I'll take Quantuum vacuum virtual plasma if there is none better...
[QUOTE=JohnnyMo1;45563736][url]http://www.reddit.com/r/Physics/comments/2c96ls/emdrive_tested_by_nasa/[/url] The /r/physics thread has a good amount of healthy skepticism as well as coherent reasons to not get excited: 1. The guy who wrote the theory paper is terrible. Plenty of outright falsehoods and poor review. 2. Very small thrust produced, so susceptible to experimental error. 3. Unequivocal violation of conservation of momentum, which is well-tested.[/QUOTE] What's your thought on the Chinese paper?
[QUOTE=zombini;45563213]There's superconductor materials now that use liquid nitrogen. They're 100X more expensive than the usual material but it works with LN2. There's some levitation demonstrations using a disc of this ceramic superconductor, just hunt around and you'll find them.[/QUOTE] They're not too expensive. The head of the physics department at my uni bought my a YBCO superconductor for a project and demonstration I did last semester and it was fairly reasonably priced. Liquid nitrogen is literally cheaper than milk, so it's not expensive to get down to its critical temperature, either.
[QUOTE=Swebonny;45563946]What's your thought on the [b]Chinese[/b] paper?[/QUOTE] Doesn't that say enough?
[QUOTE=Swebonny;45563946]What's your thought on the Chinese paper?[/QUOTE] Hard to make sense of. There's an awful lot of English and not a lot of equations (really none) in the theory part. Kind of hard to evaluate the theoretical basis for the thing when you get claims like, "Dividing the electromagnetic pressure along the cavity surface into surface integrals, the thrust produced along the frustum microwave resonator axial direction can be obtained." Great, so obtain it for me, dammit. This is your paper, not my homework.
[QUOTE=JohnnyMo1;45564017]Hard to make sense of. There's an awful lot of English and not a lot of equations (really none) in the theory part. Kind of hard to evaluate the theoretical basis for the thing when you get claims like, "Dividing the electromagnetic pressure along the cavity surface into surface integrals, the thrust produced along the frustum microwave resonator axial direction can be obtained." Great, so obtain it for me, dammit. This is your paper, not my homework.[/QUOTE] In other words, everything surrounding this stinks, and this seems to be something similar to E-Cat cold fusion device. Don't fret though Facepunch, if we wish hard enough we're still gonna get our hoverboard!
[QUOTE=Mbbird;45563576]There's hardly a single ounce of anything even approaching "cautious" in the thread.[/QUOTE] Of the 31 posts before you, I'd generously label 5 posts as outright excitement. 2 posts are speculating on the results of it being true, 7 are stating that they hope it is true, 5 are calling for caution and skepticism, 3 are jokes, and 9 are scientific discussions of varying relation to the topic.
[QUOTE=Swebonny;45564062]In other words, everything surrounding this stinks, and this seems to be something similar to E-Cat cold fusion device. Don't fret though Facepunch, if we wish hard enough we're still gonna get our hoverboard![/QUOTE] It already kind of stunk because they're trying to explain it as not violating known physics but that's bound to fail because momentum is conserved and this clearly violates that. It's certainly conserved classically and canonical momentum is conserved quantum mechanically (though I'm not certain off the top of my head that that corresponds to what we might think of as the usual) momentum conservation. It's not conserved globally in GR but this doesn't claim or look like it uses any GR effects. So basically this thing is not explainable in terms of known physics so either it doesn't work or it does work but it's an accident that it does and we really don't know why.
Even if this does turn out to be a disappointment is it not still cool that all these top scientists don't know what's going on? Surely something will come of it.
[QUOTE=Swebonny;45564062]In other words, everything surrounding this stinks, and this seems to be something similar to E-Cat cold fusion device. Don't fret though Facepunch, if we wish hard enough we're still gonna get our hoverboard![/QUOTE]So far, the future sucks. Thousands of different ways of telling people across the globe what I had for breakfast, but no space lizard bacon to go with it.
[QUOTE=Beafman;45563801]Meh. I had hoped like a cooler name like "Mass Effect Field", but I'll take Quantuum vacuum virtual plasma if there is none better...[/QUOTE] For what it's worth, you could call this thing a "flux capacitor" and be not very far off :eng101: [editline]1st August 2014[/editline] [QUOTE=JohnnyMo1;45564171]It already kind of stunk because they're trying to explain it as not violating known physics but that's bound to fail because momentum is conserved and this clearly violates that. It's certainly conserved classically and canonical momentum is conserved quantum mechanically (though I'm not certain off the top of my head that that corresponds to what we might think of as the usual) momentum conservation. It's not conserved globally in GR but this doesn't claim or look like it uses any GR effects. So basically this thing is not explainable in terms of known physics so either it doesn't work or it does work but it's an accident that it does and we really don't know why.[/QUOTE] [URL="http://emdrive.com/principle.html"]The website quote special relativity as being necessary to explain it.[/URL] [URL="http://www.emdrive.com/theorypaper9-4.pdf"]The paper there is kind of mathy too.[/URL] I can't seem to find the force on the slanted walls in the calculation though, which is a bit weird. I think there should be one, but then again I know close to nothing about high-frequency physics.
Microwave thrusters, hmm. Does that mean you'll be able to fly a rocket and cook a hot pocket at the same time?
[QUOTE=V12US;45564721]Does that mean you'll be able to fly a rocket and cook a hot pocket at the same time?[/QUOTE]so long as the superconductor stays in the socket, otherwise people will only mock it
[QUOTE=V12US;45564721]Microwave thrusters, hmm. Does that mean you'll be able to fly a rocket and cook a hot pocket at the same time?[/QUOTE] Provided this works, yes. You'd just need to puncture the container to release the stored energy in a (really dangerous) burst of microwave radiation. Some electrical capacitors in a computer are already pretty dangerous (potentially lethal), and I assume the energy stored in this thing is a lot denser and a lot more volatile.
[QUOTE=Tamschi;45563320] That's just for magnetic levitation though, the property of no electrical resistance is just temperature dependent I think.[/QUOTE] The magnetic levitation is a result of having zero electrical resistance: the induced current in the superconductor causes a magnetic field that is exactly equal and opposite to the magnetic field due to the permanent magnet. If there was any amount of electrical resistance, the superconductor (or the magnet, whichever is being suspended by the magnetic fields) would slowly sink downward.
[QUOTE=Swebonny;45562735]Yeah more or less. If it's true it's change a lot of things. Like... HOVERBOARDS.[/QUOTE] screw hoverboards, no reaction mass required means you can actually get to the speed of light, or very close to it because of interstellar drag
[quote]Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the “null” test article).[/quote] [url]http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140006052.pdf[/url] Measuring equipment could have been off or the principles behind this could have been off.
[QUOTE=Rubs10;45564920][url]http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140006052.pdf[/url] Measuring equipment could have been off or the principles behind this could have been off.[/QUOTE] Yep, that's one significant reason to be suspicious of experimental error. Thrust on the device we didn't expect to get any one.
I was kinda hoping it would be wrong for an interesting reason, like Maxwell's demon or perpetual motion machines. Experimental error is disappointing no matter how you slice it.
Johnny stop killing our fun and just tell us that we can now start building spaceships that only need electricity like in sci-fi
[QUOTE=Zeke129;45565163]Johnny stop killing our fun and just tell us that we can now start building spaceships that only need electricity like in sci-fi[/QUOTE] I will piss on all your parades if it will make you people better at science
I have a microwave let me see if I can coaborate the results
Yes it can break physics big whoop but can they make it look cool we need some artist renditions STAT
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