• Nasa validates 'impossible' reactionless space drive [Wired]
    110 replies, posted
[QUOTE=Scot;45564243]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] A lot of scientists don't know what's going on; that is the nature of science
[QUOTE=Maloof?;45565702]A lot of scientists don't know what's going on; that is the nature of science[/QUOTE] If they know what's going on, they're not really working on anything interesting.
From Sawyer's FAQ: [quote]Note however, because the EmDrive obeys the law of conservation of energy, this thrust/power ratio rapidly decreases if the EmDrive is used to accelerate the vehicle along the thrust vector. (See Equation 16 of the theory paper). Whilst the EmDrive can provide lift to counter gravity, (and is therefore not losing kinetic energy), auxiliary propulsion is required to provide the kinetic energy to accelerate the vehicle.[/quote] Great, this thing apparently has magic that can tell the difference between moving in a desired direction and moving against gravity.
Nothing new; one time I put a fork in my microwave and it exploded and flew all the way across the countertop
[QUOTE=FlakAttack;45565838]From Sawyer's FAQ: Great, this thing apparently has magic that can tell the difference between moving in a desired direction and moving against gravity.[/QUOTE] Sawyer's theory is basically garbage and that quote is just another indication that he has no idea what he's talking about.
I love how the Verge's article on it touts the fact that the control also gave a positive result as "impressive". [quote]Most impressively, the NASA team specifically built two Cannae Drives, including one that was designed to fail, and instead it worked.[/quote] [url]http://www.theverge.com/2014/8/1/5959637/nasa-cannae-drive-tests-have-promising-results[/url] [editline]1st August 2014[/editline] That's not what they were looking for, guys.
[QUOTE=Swebonny;45563946]What's your thought on the Chinese paper?[/QUOTE] literally 0 math when I read it in other words, absolutely useless [editline]1st August 2014[/editline] wait shit there's a second page and johnny takes all the fun
Why can't the universe be nice for once and give us something cool?
god damn it are we ever gonna get something more efficient than "stuff fuel and a lighter in it, ride the resulting boom"
[QUOTE=ForgottenKane;45566330]literally 0 math when I read it in other words, absolutely useless [editline]1st August 2014[/editline] wait shit there's a second page and johnny takes all the fun[/QUOTE] [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] Jeez, this Shawyer guy sure seems a bit incompetent. It turns out he didn't even link the real paper on his site, but just some kind of translation of the real paper. No mathematical equations except the error calculations are provided either for some reason. Here's the real paper, it provides equation and much better diagrams: [URL]http://cpb.iphy.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=53411[/URL] Does it seem to be reasonable at the first glance? This is way above the physics I've touched on, although it seems to just be classical physics so nothing too hard I assume? :v:
[QUOTE=Swebonny;45562653] I hope this isn't some bullshit. Because that'd mean some crazy crazy shit. 1000 W + some superconductors are able to provide 3 tonnes of thrust, without any propellant.[/QUOTE] That's like, a high end PC power supply. So in the 1% chance this isn't a crock full of shit I still wouldn't be able to afford one.
[QUOTE=Swebonny;45566713]Jeez, this Shawyer guy sure seems a bit incompetent. It turns out he didn't even link the real paper on his site, but just some kind of translation of the real paper. No mathematical equations except the error calculations are provided either for some reason. Here's the real paper, it provides equation and much better diagrams: [URL]http://cpb.iphy.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=53411[/URL] Does it seem to be reasonable at the first glance? This is way above the physics I've touched on, although it seems to just be classical physics so nothing too hard I assume? :v:[/QUOTE] At least it doesn't look as terrible as the other stuff. The thrust they measured is notably in the opposite direction from the one the theory guy said it would point in though (if I interpret this stuff correctly). Probably because he discounted the side walls. [editline]2nd August 2014[/editline] I haven't actually read all of it though, and I can't fact-check the physics because I don't know anything about radiation pressure etc. (Well, maybe a little, but not so well that I could just punch stuff into a calculator and tell if it's solid.)
[QUOTE=ironman17;45562736]Let's hope this is real, although considering that this is a universe that fucks us over at every opportunity, it's probably not. Reactionless drives using the virtual plasma of the quantum vacuum, thus not being able to run out of fuel, would be a GOOD thing, and humanity doesn't get good things.[/QUOTE] Fuck that shit, my whole life I've pondered on the considerations of the multi-verse and how fucking limited ours is in the awesome science department, this is something we need. I really really don't want to believe all that we live in with all we've done and so far all that we've discovered [i]might[/i] be [i]it[/i], end of the good stuff leaving us with nothing to do but go extinct. If this reaction-less EMdrive works like they say it does using plasma that's not there in the quantum vacuum, then I'm all for it. We're denied all of the other awesome shit we've come up with over the few hundred years of dreaming up sciency shit, may as well have [i]something[/i] that does work, in that weird almost surreal sciency way. I refuse to believe our universe is as dull as we're complacently believing it is, we simply have not found the good stuff yet and this may be the start. /rant
[QUOTE=Scientwist;45568474]Fuck that shit, my whole life I've pondered on the considerations of the multi-verse and how fucking limited ours is in the awesome science department, this is something we need. I really really don't want to believe all that we live in with all we've done and so far all that we've discovered [i]might[/i] be [i]it[/i], end of the good stuff leaving us with nothing to do but go extinct. If this reaction-less EMdrive works like they say it does using plasma that's not there in the quantum vacuum, then I'm all for it. We're denied all of the other awesome shit we've come up with over the few hundred years of dreaming up sciency shit, may as well have [i]something[/i] that does work, in that weird almost surreal sciency way. I refuse to believe our universe is as dull as we're complacently believing it is, we simply have not found the good stuff yet and this may be the start. /rant[/QUOTE] imo if you think the universe as we know it is dull, you don't know enough physics
[QUOTE=JohnnyMo1;45568831]imo if you think the universe as we know it is dull, you don't know enough physics[/QUOTE] but there are no observable clusters of planets all within a lightyear of each other with stable orbits that all exist in the habitable zone of multiple differently-colored cool-looking stars and hold an atmosphere with breathable levels of oxygen and neutral gases and with gravity comparable to Earth! >:(
[QUOTE=JohnnyMo1;45568831]imo if you think the universe as we know it is dull, you don't know enough physics[/QUOTE] Ok, well maybe not[i]dull[/i] per se, but not as exciting as one would hope or like it to be. I have an idea what with all science stuff I follow, but there has always been a nagging feeling that there is even more. [editline]2nd August 2014[/editline] [QUOTE=DChapsfield;45569173]but there are no observable clusters of planets all within a lightyear of each other with stable orbits that all exist in the habitable zone of multiple differently-colored cool-looking stars and hold an atmosphere with breathable levels of oxygen and neutral gases and with gravity comparable to Earth! >:([/QUOTE] I know your being slick, but multi-verse theory means all of what you said can, may or does exist, so it's cool.
[QUOTE=Swebonny;45566713]Jeez, this Shawyer guy sure seems a bit incompetent. It turns out he didn't even link the real paper on his site, but just some kind of translation of the real paper. No mathematical equations except the error calculations are provided either for some reason. Here's the real paper, it provides equation and much better diagrams: [URL]http://cpb.iphy.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=53411[/URL] Does it seem to be reasonable at the first glance? This is way above the physics I've touched on, although it seems to just be classical physics so nothing too hard I assume? :v:[/QUOTE] from the paper [t]http://puu.sh/aBkJq/a5a2bcb45c.jpg[/t] "thrid"
[QUOTE=EvacX;45570391]from the paper [t]http://puu.sh/aBkJq/a5a2bcb45c.jpg[/t] "thrid"[/QUOTE] A typo in something written by someone with Asian language background who probably didn't major in English. Congratulations for finding this  (I agree that the language is a bit strange at times, but it's better than what I've seen from some native speakers. Most things seem to be vocabulary stuff that's used differently in their native language. That said, it's generally not a bad idea to let someone who knows English very well proof-read things before publishing.) [editline]2nd August 2014[/editline] [QUOTE=Swebonny;45566713]Jeez, this Shawyer guy sure seems a bit incompetent. It turns out he didn't even link the real paper on his site, but just some kind of translation of the real paper. No mathematical equations except the error calculations are provided either for some reason. Here's the real paper, it provides equation and much better diagrams: [URL]http://cpb.iphy.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=53411[/URL] Does it seem to be reasonable at the first glance? This is way above the physics I've touched on, although it seems to just be classical physics so nothing too hard I assume? :v:[/QUOTE] I read through it, theoretically it's sound, but the numerical simulation is not linked. (It seems to be in some journal.) If there's an error it's most likely in the experiment and simulation, though that's something people who actually know this stuff really well (and have access to the original data) can check much better than me. The paper makes no attempt at explaining the underlying physics, it only shows how they explain the deviation the experiment shows from the simulation. (Which seems sound to me, it's not very complicated. I didn't do any number-crunching whatsoever though.)
Quoted from myself in KSP forums(edited because FP allows for some ....): [QUOTE] Validation method: As this is an RF cavity reactionless drive, instead of Woodward effect / QVP thruster, make the endplate removable. Test the engine with endplate and without endplate, put the endplate on top of the engine so the mass stays constant. If the thrust is similar, then they have reinvented photon drive, and there is nothing interesting going on. If the thrust is higher than the engine without endplate, then some very weird shit is going on [/QUOTE] The ultimate test: Bring all of those supposed 'reactionless drive' up there, into orbit, and fire them. See if they are actually moving or not. Isn't practical though
[QUOTE=sltungle;45563977]Liquid nitrogen is literally cheaper than milk, so it's not expensive to get down to its critical temperature, either.[/QUOTE]Considering that one can make liquid nitrogen at home (and then quickly find out why your average person should not be allowed access to liquid nitrogen) yeah, cheaper than milk.
[QUOTE=FlakAttack;45565838]From Sawyer's FAQ: Great, this thing apparently has magic that can tell the difference between moving in a desired direction and moving against gravity.[/QUOTE] So it can't work on water, unless you have power? Well Marty's screwed unless he jumps off the thing before Griff biffs him round the bonce.
[QUOTE=ironman17;45562736]Let's hope this is real, although considering that this is a universe that fucks us over at every opportunity, it's probably not. Reactionless drives using the virtual plasma of the quantum vacuum, thus not being able to run out of fuel, would be a GOOD thing, and humanity doesn't get good things.[/QUOTE] It could also be the most destructive weapon in the history of humanity. If it can be made as efficient as they claim, what's stopping someone from accelerating something to light speed and aiming it at someone they don't like?
[QUOTE=Firefox42;45573918]It could also be the most destructive weapon in the history of humanity. If it can be made as efficient as they claim, what's stopping someone from accelerating something to light speed and aiming it at someone they don't like?[/QUOTE] idk...the laws of physics? You'll struggle to get anything close to C, even with this engine working perfectly.
[QUOTE=Firefox42;45573918]It could also be the most destructive weapon in the history of humanity. If it can be made as efficient as they claim, what's stopping someone from accelerating something to light speed and aiming it at someone they don't like?[/QUOTE] Any kind of really good acceleration device for space travel makes for a good impact weapon, that's the harsh reality of momentum.
To make something move is to give it momentum. If something gets momentum in one direction, then something must get an equal amount of momentum in the opposite direction (conservation of momentum). Momentum is mass times velocity. Information can only be transmitted at or less than the speed of light. If mass is zero, then the "reactant" is travelling at the speed of light. The only thing that can travel at the speed of light is light itself. This then becomes an ordinary photon thruster. If the mass is greater than zero, then the drive is no longer reactionless, as the ship continually loses mass. But what if you had a very small-mass particle, and accelerated it to a fraction of the light speed, giving it the maximum momentum it can carry? Depending on how you do it, you could end up with an ion engine. Why don't photon or ion engines go fast? I don't know. Maybe it has to do with the fact that by giving a particle a momentum, you also give it kinetic energy, and on-board systems can only feed energy into the engine so fast. Maybe our engines are just not very good. Or maybe they are very good but it is physically impossible to accelerate faster while expelling less than X amount of mass and using less than Y amount of energy. If space were filled with some kind of gas, you could get away with expelling a lot of reaction mass, because the reaction mass would just be replenished from the environment again. But there is just not enough stuff in space for our engines to work like that. Plus, a spacecraft that takes stationary matter from space would be limited in speed by the exhaust velocity of it's engine (if you are going really fast and catch a stationary ball, then throw it backwards only kinda-fast, then you will still slow down). Maybe some kind of weird momentum-exchanging thingy can be made based on the wibbly-wobbly and bendy properties of space, but I have no idea how that would work.
[IMG]http://i.imgur.com/4jtEfOW.jpg[/IMG]
[QUOTE=Nikita;45575358]To make something move is to give it momentum. If something gets momentum in one direction, then something must get an equal amount of momentum in the opposite direction (conservation of momentum). Momentum is mass times velocity. Information can only be transmitted at or less than the speed of light. If mass is zero, then the "reactant" is travelling at the speed of light. The only thing that can travel at the speed of light is light itself. This then becomes an ordinary photon thruster. If the mass is greater than zero, then the drive is no longer reactionless, as the ship continually loses mass. But what if you had a very small-mass particle, and accelerated it to a fraction of the light speed, giving it the maximum momentum it can carry? Depending on how you do it, you could end up with an ion engine. Why don't photon or ion engines go fast? I don't know. Maybe it has to do with the fact that by giving a particle a momentum, you also give it kinetic energy, and on-board systems can only feed energy into the engine so fast. Maybe our engines are just not very good. Or maybe they are very good but it is physically impossible to accelerate faster while expelling less than X amount of mass and using less than Y amount of energy. If space were filled with some kind of gas, you could get away with expelling a lot of reaction mass, because the reaction mass would just be replenished from the environment again. But there is just not enough stuff in space for our engines to work like that. Plus, a spacecraft that takes stationary matter from space would be limited in speed by the exhaust velocity of it's engine (if you are going really fast and catch a stationary ball, then throw it backwards only kinda-fast, then you will still slow down). Maybe some kind of weird momentum-exchanging thingy can be made based on the wibbly-wobbly and bendy properties of space, but I have no idea how that would work.[/QUOTE] Yahoo!'s article had this to say: [quote=Yahoo!][b]The thruster may work by somehow harnessing the subatomic particles that continuously pop into and out of existence,[/b] the NASA researchers suggest. The results and the technology are promising enough to warrant further study, they wrote in the study.[/quote] Maybe it works with subspace? Being subatomic particles "pop in and out of existence", maybe the EMdrive uses the particles as something to push on giving it propulsion? Just a guess though.
[QUOTE=Nikita;45575358]If mass is zero, then the "reactant" is travelling at the speed of light. The only thing that can travel at the speed of light is light itself.[/QUOTE] This part isn't 100% true. The gluon also has no mass (although it's confined to subatomic, hell, subnuclear levels). If the graviton exists it will also have no mass.
This is neat, but does anyone find it fishy that NASA was able to observe 30-50uN of thrust, where as the Chinese team was able to observe 720mN? That is a pretty huge difference, and given that this phenomena has yet to be explained...
[QUOTE=Laserbeams;45562737]Please be true, once we get flying cars we are officially living in sci-fi[/QUOTE] More like air traffic hell. Don't even get me started on the fatality rates below. The only reason air fatalities are low is because less planes are used for private transport than cars are. You ever see that one episode of Doctor Who?
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