Slashdot Mirror
German Scientists Confirm NASA's Controversial EM Drive
MarkWhittington writes: Hacked Magazine reported that a group of German scientists believe that they have confirmed that the EM Drive, the propulsion device that uses microwaves rather than rocket fuel, provides thrust. The experimental results are being presented at the American Institute for Aeronautics and Astronautics' Propulsion and Energy Forum in Orlando by Martin Tajmar, a professor and chair for Space Systems at the Dresden University of Technology. Tajmar has an interest in exotic propulsion methods, including one concept using "negative matter."
Maybe this will be one that turns out not to be a scam...
told all y'all non-believers!
I am going to go check starcitizen website to see if this has been implemented yet.
Until Mythbusters confirms it, I'll just say it's Plausible.
Harrison's Postulate - "For every action there is an equal and opposite criticism"
If you don't need to carry propellant, not only can you get to Pluto in 18 months, you could probably decelerate and get into orbit. This could make for some exciting exploration of our solar system. And maybe we can catch/pass Voyager with a new interstellar probe?
This is the type of news I want to see more of. Between all of the pointless social narcissism platforms and SJW Bs this is enlightening news. I am excited to see what discoveries will be made. And if it turns out to be bunk, well who cares that's science!
I don't understand how carrying and burning all of those microwaves would be better than rocket fuel, especially with the production cost of making the microwaves.
It's amazing how little science exists within science these days. Everyone has lost touch with reality.
What more do I need to say?
This is really amazing and hopefully it is turning into a window into parts of our universe that we've never imagined.
But, reading the articles, I think we're a long way off from understanding what this phenomena is and how to exploit it practically. Going back over the previous articles, the measured force was for 50 uN from 50W of power - this doesn't seem like a very practical application as yet; the claims of round trips to Mars in less than a year are very exaggerated.
On that point, I thought we could go to Mars in 3 months or so now; it just takes a nuclear rocket rather than chemical, plasma or EM drives.
Finally, in the hacked.com article, rather than expelling "propellant", aren't you expelling "reaction mass"?
Mimetics Inc. Twitter
A propulsion device that provides thrust without using reaction mass would be an earth-shattering advance, assuming the amount of thrust is non-negligible. I hope you do get that.
I'm very hopeful this works. It's easy to be cynical, so I won't say "meh it's all bullshit!" Still, I won't be convinced until I see it provide thrust in a vacuum, away from Earth's magnetic field. It's still far, far too likely it's pushing off something terrestrial. So I'll give them a healthy "go, team, go!"
That said, quoth the article:
"This is the first time that someone with a well-equipped lab and a strong background in tracking experimental error has been involved, rather than engineers who may be unconsciously influenced by a desire to see it work," notes Wired referring to Tajmar's work.
I don't know about that. He is a real professor at a real university, but he also has filed for a patent on a gravity generator, using a process no one has duplicated. Somebody who thinks they've got a gravity generator, but gosh just can't prove it to everybody else, is definitely somebody who may be "unconsciously influenced by a desire to see it work."
We don't have a state-run media we have a media-run state.
To paraphrase Charles Fort (blessings upon his name) It's spindizzies when it's spindizzy time.
Read the CE3 reports. Pay attention to how these "advanced" "aliens" behave. Not the sharpest crayons in the bag. If they can figure out interstellar transdimensional travel, it's not that hard. We just haven't looked in the right place.
In the conclusion section:
The nature of the thrusts observed is still unclear. Additional tests need to be carried out to study the magnetic
interaction of the power feeding lines used for the liquid metal contacts. Our test campaign can not confirm or refute
the claims of the EMDrive but intends to independently assess possible side-effects in the measurements methods
used so far. Nevertheless, we do observe thrusts close to the magnitude of the actual predictions after eliminating
many possible error sources that should warrant further investigation into the phenomena. Next steps include better
magnetic shielding, further vacuum tests and improved EMDrive models with higher Q factors and electronics that
allow tuning for optimal operation. As a worst case we may find how to effectively shield thrust balances from
magnetic fields.
F=MA
The mass at either end is different. Force acts over an area, both ends have different areas.
Motion is expected.
If somebody still has the article on their screen, please post a text copy-paste.
If it weren't for deadlines, nothing would be late.
Ahem ... that would be an _ostensible_ propulsion device, the working principle for which is (according to mainstream physicists) poorly described and violates commonly accepted physical principles. OTOH, I hope it works. I'll believe it when they cram a couple of megawatts in, and get it to lift its own weight - or better, 100 times its own weight.
I note that the Dr. Tajmar, the researcher whose name is on the paper, is still using terms like "... if true ...". This is not yet a tried-and-true propulsion device. The articles I saw just now did not show actual numbers, but the NASA experiment used such low power that the apparent thrust was well below several of the potentially confounding effects; i.e. the noise was much higher than the signal. It may still turn out to be the result of some experimental error, an unexpected issue with the apparatus, etc. Again though, one hopes. :)
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
I don't understand why this is so 'unbelievable'. We have had methods of providing thrust in space without using rockets since 1916, the year the first ion thruster was built. Both use electricity to produce thrust.
What is bugging me is that every article about this 'em drive' claims that it doesn't use any fuel, it makes it sound like a free energy machine. Is electricity not a fuel?
What I would like to see is a comparison between this new 'em drive' and an ion thruster. How much electricity they consume for the same amount of thrust, which accelerates faster, etc.
Until then I can't really get excited about it. It might be a new method of propulsion, but if it is inferior to other methods we have had for nearly a century, what's the point?
https://en.wikipedia.org/wiki/...
How is this any better than an ion thruster?
Tajmar made a lot of hoopla over ten years ago about making gravitomagnetic waves orders of magnitude more powerful than GR predicted; some were claiming we were on our way to artificial gravity or a warp drive by his bold claims. Of course, his experiments could never be duplicated. Since then, he's been trying to make waves (ha!) with other dubious claims of making gravity effects by electromagnetic means and such.
Take anything he claims "confirmed" with a one hundred pound bag pinch of salt.
This could provide a basis for a 'constant acceleration drive', that could travel interstellar distances without requiring a reaction mass
https://en.wikipedia.org/wiki/...
Wherever You Go, There You Are
"...Tajmar has an interest in exotic propulsion methods...". Look up the BBC episode of "Heretics of Science" about Professor Eric Laithwaite.
Ion thrusters still consume raw materials, so there's a finite fuel supply. If this does literally turn electricity into thrust without consuming anything then running out of reaction-mass is no longer an issue, and some probes could even be entirely solar powered.
Do not look into laser with remaining eye.
Ions have mass?
Ion engines push with the amount of force of a piece of paper on one's hand. They still achieve stupendous speeds through doing this indefinitely. If this thing can match that performance over that timescale then it's still useful.
Do not look into laser with remaining eye.
Real question here-- I ask out of partial ignorance.
How is this different from say using light, a form of electromagnetic radiation? Everyone has seen a radiometer (the thing with the black and white vanes that spins when in light. My thought experiment is if you have a directional light source that is pointed at a radiometer, that will cause the radiometer to spin, i.e. impart a thrust on the radiometer. That means there must be an equal and opposite force imparted on the light source. I would imagine this would work in a vacuum-- it is light after all. Isn't this another example of electromagnetic radiation (light) giving thrust?
An ion thruster still uses reaction mass, those Xenon ions have mass, you know. It's more reaction-mass-efficient than a chemical rocket because the exhaust velocity of the ions is a lot higher - the higher the exhaust velocity, the more thrust per unit of reaction mass you get. But you still carry a finite amount of reaction mass with ion thrusters, so you still aren't going very far with them.
researchers in India are experimenting with the imact of a transverse magnetic field, creating a "Tajmar-Hall" effect...
Just thinking about this, how expensive would it be to create a small, simple satellite, with solar cells, some large LiPoly batteries, a transponder and an EM drive that fires up every time there is enough juice in the batteries to run it for a few minutes?
Sticking with the 50nN thrust level for 50W of input and assuming that a 1kg LiPol battery has 260Whr available (https://en.wikipedia.org/wiki/Lithium_polymer_battery), that is approximately 5hr of running time and assuming that the satellite is 5kg, there will be a 10nm/s^2 acceleration.
5 hours is 18,000s so there should be a delta-V imparted on the satellite of 1.8(10^-4)m/s which is tiny (I did say this is a pretty useless drive at the current time right now) but should be measurable or at least noticeable to its relative position to a control satellite that was launched along with it.
Mimetics Inc. Twitter
A ion drive requires reactionary mass to work. Thus, while very efficient, a ion drive is limited to the amount of mass it carries around as fuel.
A reactionless drive, which this claims to be, does not require any fuel. It only needs energy. Most sterilities fail because they run out of fuel not because their electronics go buggy. In theory one could stick larger solar panels and a EM drive and greatly extend their lives. In theory.
Of course they do. Ions are simply an atom that has either gained or lost electrons and now has a net electric charge, either (+) or (-). As such, they are made up of protons, neutrons and electrons, all of which have mass.
Bad example. Light does exert radiation pressure, yes - but it is far, far too weak to drive a radiometer. The spinning radiometer isn't due to radiation pressure. It's a more mundane effect: Imperfect vacuum. The black side is warmed more than the white, which heats up adjacent air, which exerts higher pressure, causing the spin. It's just a plain old heat engine.
An Ion thruster still requires reaction mass. Once that reaction mass runs out, you are dead in space. If this EM Drive actually works, then it would only need energy that it can turn in to microwaves, which it could get from, say solar panels or a MMRTP, like the Curiosity rover has.
Existing electric propulsion devices (like ion thrusters) still use propellant, they're just really efficient.
The EM drive would appear to use no propellant, meaning the limitations would only be the amount of electricity that could be produced, along with how long the EM drive could operate before it degrades.
Until you travel at 0.7c and you discover the batteries are dead because solar isn't working at this speed so you cannot slow down.
Was this not invented by a limey that got upset at the west for not looking at it, so took it to china? Or was that something else?
I prefer the "u" in honour as it seems to be missing these days.
A radiometer doesn't use photon pressure. It heats one side of a plate in a partial vacuum, gas bouncing of that side of the plate picks up thermal energy generating 'thrust'.
Photon drive, is a maybe, but no one has made a workable one yet and where are you getting all the photons from ?
Jesus, I speak with so many voices!
Lifting its own weight is irrelevant. Existing electric propulsion thrusters couldn't come remotely close to lifting their own weight, and yet are still in active use in space.
So the reproduction of the reproduction of the reproduction of the experiment still leaves you disbelieving?
I agree, a scale-up is in order so we can get a better look, but surely by now, it's clear we are looking at something new even if it's not what we think it is.
This is how it begins
It appears to impart momentum to something without an opposite momentum imparted to anything else... you know, the basic concept of how every other propulsion system in the world works?
When you walk, your feet push against the ground, imparting a (tiny, relative to the mass of the Earth) amount of momentum to it at the same time that your feet impart momentum to your body.
When you sail a boat, the sails alter the momentum of the wind, and an opposite alteration is imparted to the momentum of the boat.
When a rocket engine fires, it releases exhaust with a lot of momentum going one way, and the rocket receives the momentum going the other way.
This model holds for any kind of propelling of anything. Even a flashlight projecting photons imparts a tiny, tiny bit of momentum to your hand, to your body, to the earth. Magnetic propulsion, chemical propulsion, ion propulsion... all of them operate on the principle of "we go this way, by making something else go that way".
The EM Drive appears to go one way without making anything else go the other way. It releases no exhaust, pushes against no solid or fluid, emits no photons, and interacts with no external magnetic fields. We don't know how it works (there are a number of theories, none of which are that widely accepted), and we still aren't 100% sure it does work (maybe it's still all experimental error... that becomes less likely with each independent verification, but extraordinary claims call for extraordinary evidence), but if it does work it does so in a way that is outside our current understanding of physics. That is a Really Big Deal.
One way or another, this is exciting!
There's no place I could be, since I've found Serenity...
It sounds like they've been shielding it against external fields including the Earth's magnetic field but how do you shield it from gravity. I hope they can do an experiment in space ASAP.
An ion thruster is a very efficient reaction mass based thruster,
It still has to drag all that reaction mass along, despite it's only real purpose being that it's thrown out like garbage just to provide thrust.
It takes thrust to push that reaction mass around the place, up until you actually throw it out the window, which is actually out the directed nozzle or whatever.
And what happens when you run out of reaction mass? You have no more thrust.
On the other hand, if you have a reactionless thruster, as long as you provide it with power, it will give you thrust. Slap on solar panels, or if it's a deep space mission, nuclear batteries or the like, and you are set.
As an added bonus, you can use that constant acceleration trick to really build up some speed. Something you can't do with reaction mass because you don't ever have enough, even for a tiny trip like to the moon.
Harvest heat from the microwave background and then push it back out at the wavelength and direction of one's choice. Might not be the most bountiful source of energy in the universe, but it's mostly everywhere ;)
I know this is Slashdot, but the abstracter of the paper is pretty clear:
"Our test campaign can not confirm or refute the claims of the EMDrive"
http://arc.aiaa.org/doi/10.2514/6.2015-4083
How did we get from that to the summary posted here? Why does the happen every single time an article about this appears on Slashdot?
Solar sails and photon drives produce far less thrust than what is claimed to be being measured with these EM drives. If something real is going on here, it is also almost certain that the experiments represent a sub-optimal design. Nobody has a clue how an EM drive produces thrust. Once that's figured out, if there's something to figure out, more efficient designs can be had producing more thrust with less input.
Two of my imaginary friends reproduced once
Scientists Confirm 'Impossible' EM Drive Propulsion
Science News, Space / July 27, 2015 / by Giulio Prisco/
Later today, July 27, German scientists will present new experimental results on the controversial, "impossible" EM Drive, at the American Institute for Aeronautics and Astronautics' Propulsion and Energy Forum in Orlando. The presentation is titled "Direct Thrust Measurements of an EmDrive and Evaluation of Possible Side-Effects."
Presenter Martin Tajmar is a professor and chair for Space Systems at the Dresden University of Technology, interested in space propulsion systems and breakthrough propulsion physics.
A Revolutionary Development for Space Travel
The EM Drive (Electro Magnetic Drive) uses electromagnetic microwave cavities to directly convert electrical energy to thrust without the need to expel any propellant. First proposed by Satellite Propulsion Research, a research company based in the UK founded by aerospace engineer Roger Shawyer, the EM Drive concept was predictably scorned by much of the mainstream research community for allegedly violating the laws of physics, including the conservation of momentum.
However, NASA Eagleworks – an advanced propulsion research group led by Dr. Harold G. “Sonny” White at the Johnson Space Center (JSC) – investigated the EM Drive and presented encouraging test results in 2014 at the 50th Joint Propulsion Conference.
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 and eliminating the need to carry propellant. While a number of scientists criticize White's theoretical model, others feel that he is at least pointing to the right direction. The NASASpaceFlight website and forums have emerged as unofficial news source and discussion space for all things related to the EM Drive and related breakthrough space propulsion proposals such as the Cannae Drive.
Shawyer has often been dismissed by the research establishment for not having peer-reviewed scientific publications, but White and Tajmar have impeccable credentials that put them beyond cheap dismissal and scorn. Physics is an experimental science, and the fact that the EM Drive works is confirmed in the lab. "This is the first time that someone with a well-equipped lab and a strong background in tracking experimental error has been involved, rather than engineers who may be unconsciously influenced by a desire to see it work," notes Wired referring to Tajmar's work.
Hacked has obtained a copy of Tajmar's Propulsion and Energy Forum paper, co-authored by G. Fiedler.
"Our measurements reveal thrusts as expected from previous claims after carefully studying thermal and electromagnetic interferences," note the researchers. "If true, this could certainly revolutionize space travel."
"Additional tests need to be carried out to study the magnetic interaction of the power feeding lines used for the liquid metal contacts," conclude the researchers. "Nevertheless, we do observe thrusts close to the magnitude of the actual predictions after eliminating many possible error sources that should warrant further investigation into the phenomena. Next steps include better magnetic shielding, further vacuum tests and improved EMDrive models with higher Q factors and electronics that allow tuning for optimal operation."
Contrary to sensationalist reports published by the sensationalist press, the EM Drive is not a "warp drive" for faster than
There's no place I could be, since I've found Serenity...
Try looking up "N rays" for an ancient example of how scientists can fool themselves.
Thank you for enlightening me. I read the wikipedia page on radiometers: https://en.wikipedia.org/wiki/...
I learned that radiometers do NOT work by "light pressure" which was Crooke's, the inventor's, hypothesis. Radiometers do NOT spin in a perfect vacuum. The two mechanisms that explain why they spin were proposed by the likes of Einstein (relativity guy), Maxwell (equations guy), and Reynolds (number, not aluminum, guy).
Confirming propellantless thrust from a 2nd Generation superconducting EM Drive would outweigh local effects. (http://emdrive.com/secondgenengines.html) 2G (2nd Gen.) testing started in 2006, according to Roger Shawyer's paper: http://www.emdrive.com/2Gupdat...
That would be pretty hilarious, although I would hope to have some compact fission/fusion reactor with about twice the expected life of the trip as a primary power source...
Things do go wrong... I remember an old Heinlein story where Cu (I think) was used to power their star-drive and somebody sent him and another astronaut on a 'one way trip to oblivion'.
They managed to react enough copper out of her wedding band to effect an escape, since Heinlein only killed a few of his protagonists
Wherever You Go, There You Are
How is this any better than firing a laser out the back of the drive? Can't create momentum out of nothing. Does a KW of microwave photons provide more thrust than a KW of (say) infra-red laser photons?
they're just really efficient in a vacuum.
Fixed that for you. Well, for your reader anyway - you probably understand it. Because of the way these things work, they are just about useless anywhere other than a vacuum. The only way you can spend a tiny tiny amount of energy accelerating particles to massive speeds is when there's nothing else in their way for them to bounce off of. But if you are not in any kind of rush for your delta v and are in near total vacuum this is almost a perfect engine.
Seven puppies were harmed during the making of this post.
Poul Anderson's Tau Zero
EM drive. You are making a magnet except not with magnetism. you are causing the engine to move towards something it is attracted to. that something could be infinite distance away. is the engine direction?
You are setting up some type of gradient. small amount of radiation particles on one side, large radiation particles on the other. it causes them to repel? if you have an opening, then this causes trust.
radiation particles just want to move away from each other. its like pumping air into a balloon, but its an infinite amount of radiation particles?
My name is Legion...
AIAA PROPULSION 2015, Propulsion & Energy Forum of the American Institute of Aeronautics and Astronautics in Orlando, FL
Wednesday, 29 July 2015: 129-NFF-5 0900 - 1200 hrs
Conversations in Breakthrough Propulsion Physics: Gravity
Round table members:
Dr. George J. Williams, Senior Scientist, Ohio Aerospace Institute, NASA Glenn Research Center
Prof. Martin Tajmar, Dresden Univ. of Technology, Dresden, Germany
Dr. Bryan A. Palaszewsk, Senior Scientist, NASA Glenn Research Center, Cleveland, OH
Something is going to be generating the electricity to create those microwaves, and THAT is going to require some sort of fuel. There is no free lunch. Perpetual motion does not exist. And ya cannae change tha laws of physacks Jim.
Seven puppies were harmed during the making of this post.
"Our test campaign can not confirm or refute the claims of the EMDrive but intends to independently assess possible side-effects in the measurements methods used so far."
https://www.reddit.com/r/EmDri...
Oh you'll slow down alright. Eventually. In a spectacular fireworks display when you slam into some planet/star that got in your way... you probably won't be alive by then though.
Seven puppies were harmed during the making of this post.
As an added added bonus, such a drive would accelerate faster at a given thrust, because of the absence of reaction mass. Conventionally, acceleration steadily increases at a given thrust as reaction mass is ejected, with maximum acceleration being reached just before reaction mass is exhausted.
We can dream, can't we?
I wrote a comment on this up above, but just to help you understand...
1) No, the ion drive does not use electricity to produce thrust. Ion drives, as their name suggests, use ions to produce thrust. The ions are accelerated using fields generated via electric power, but that's no more a case of using electricity to (directly) produce thrust than an electric car is (the car pushes against the road, imparting momentum to the earth which balances the momentum imparted to the car).
2) Yes, it sounds like a free energy machine. If a given amount of electrical power produces a given thrust, constantly, without consuming any fuel, then you can generate unlimited energy by attaching this thing to a flywheel or rotor arm that drives a generator and it will produce more energy than it requires to drive the thruster. Some of the current theories about this thing claim that it won't do that, that its efficiency will go down the faster it's moving (relative to a given frame of reference).
3) No, electricity is not fuel. Electricity is not a thing. It is a process. Electricity is the motion of electrons. It is a form of energy. Fuel is a way to store energy, but it is not energy itself. You can generate electricity from many things, including fuel, and there are many forms of chemical devices with electrical potential energy - we usually call them batteries - but electricity is not, itself, fuel. Now, the energy still needs to come from somewhere (unless this drive does turn out to be usable to get more energy out than is put in, which would turn *all* of physics on its head) and that "somewhere" is usually fuel of some kind... but it can be things like uranium in a nuclear reactor that is usable for decades from a tiny amount of mass, or hydrogen in the sun producing photons as it fuses and those photons being captured and used to move electrons via the photoelectric effect (in layman's terms, solar panels).
There's no place I could be, since I've found Serenity...
If this were proven to work, enormous R&D would take place, in multiple countries independently (aka a new space race).
While I doubt it would ever replace the first stage, improved designs would cut down on the necessary amounts of fuel.
Here's a nuclear reactor and bon voyage for your trip to Mars.
I will however not believe in it until I see it sold as a toy (imagine a solar-powered flying saucer for kids, replacing your He baloon). Or a levitating skateboard ?
And where would the colder place be to vent that heat? Sacre bleu!
-Yours, S. Carnot.
The fuel (energy storage) used to produce the electricity doesn't need to be internal to the craft, though. Photovoltaic panels, for example, take electromagnetic energy (photons), such as stars (big balls of fuel) produce, and turn it into electricity. A magnetron (such as the one inside an EM Drive) can turn that electricity back into electromagnetic energy. You now have a relatively tiny craft that can thrust forever so long as there's a star close enough to provide photons (in reasonable quantity). Maybe not viable for a starship, but it could completely revolutionize intra-system travel.
There's no place I could be, since I've found Serenity...
Here is the first page of the actual paper, including the abstract which says:
Our test campaign can not confirm or refute the claims of the EMDrive but intends to independently assess possible side-effects in the measurement methods used so far.
So the /. title says pretty much the exact opposite of what the actual
paper says.
I am still extremely skeptical that there is any actual effect. They powered their device with a 700 watt magnatron and measured plus or minus 20 micro-newtons of thrust. To put this in perspective, one Newton is roughly the weight of an apple near the surface of the Earth. If the thrust scales linearally with input power then you would need 50,000 x 700 Watts = 35 Megawatts to levitate a single apple. Of course the inventor claims that the thrust to power ratio is highly non-linear so at these higher power levels you would get a lot more thrust. I have not seen any sensible theoretical model that explains why this would be so.
If you are using hundreds of watts to produce a handful of micro-newtons then it is extremely likely there is no actual effect and what is being measured is just some form of noise. This is especially true when the so-called effect violates a primary law of physics.
We don't see the world as it is, we see it as we are.
-- Anais Nin
Not indefinitely, just over a long time. Ion engines consume fuel (which they ionize, and then throw the ions out the back of the drive, hence the name) so an ion engine still needs to haul its reaction mass along for the ride, and stops being able to thrust once it runs out of stuff to ionize and expel.
There's no place I could be, since I've found Serenity...
Could the blue-shifted light in front be harnessed as an energy source at that speed? At some speed, something would have to keep it from frying the ship. Converting that into energy would be a bonus.
Put it on a cheap and simple satellite, piggyback it on another satellites launch and run it for a few months/years. From what I understand this thing has such a small thrust that its difficult to differentiate between any possible thrust and instrument noise (earthquakes, cars/trains driving by, magnetic fields, etc). A real world test where a craft with no other means of propulsion can/can't change its orbit is the only way to be sure.
Except solar panels lose power over time. You know, entropy and all that. Plus if you're moving away from the very star powering your craft, well then "forever" is not as long as you'd like.
Seven puppies were harmed during the making of this post.
reaction-mass is no longer an issue, and some probes could even be entirely solar powered.
There still has to be a reaction-mass though, you can't create energy from nothing. It's simply that the reaction-mass *is* some proportion of the mass of the photons that hit the craft, are converted energy to move the electrons, which are then converted into microwaves, which through some unknown mechanism generate a force.
Personal opinion is this a bit like the opposite of a solar sail. Microwaves are high energy photons. So they still have a mass. If you emit the microwaves in one direction then that means you're pushing a certain mass in that direction. There's a corresponding opposite force that pushes you in the other direction. If the microwaves pass through the wall of the craft without 100% of them getting absorbed then you do not have them cancelling that force out at the other side, so you'll get a net force movement. Mount the magnetron on a gimbal and you can push the craft in any direction (subject to shielding the craft from the microwaves).
Nothing in the way? Space isn't altogether empty
Dude, you have a cow fetish. I worry for the ones on your farm, they likely have some serious butt hurt......
Someone needs a visit from Zombie Feynman!
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
You aren't following what he is saying--the research is saying is that THERE IS NO REACTION MASS. Per current physics, this device can't exist. That is why this is so big. No current physics explains it. It is not the opposite of a solar said, since the microwaves don't actual exit the device. If this device works, it does change everything, if only to point to new physics.
if you reread my post: "near total vacuum". It's empty enough.
Seven puppies were harmed during the making of this post.
True, but this means your source of energy can be very compact and efficient.
For instance, you can employ a nuclear reactor. Still somewhat heavy and complex, but a lot lighter, and much more efficient than having to carry your reaction mass with you just so you can shoot it out the back. If we got reactor design compact and advanced enough, it could actually be fairly simple to operate.
Previously, the only way to make use of nuclear power was to basically accelerate the ship by throwing nuclear bombs out the back. A reactor isn't as dramatic, and doesn't accelerate as drastically, but is significantly more efficient, and reusable (not to mention it isn't a proliferation risk).
That would make it possible for the ship to reach higher velocities as well, since the ship would have less mass, or alternately, be able to have more non-propulsion mass which would be handy in dealing with the other issues with long range spaceflight.
A ion drive requires reactionary mass to work.
I've been quoting Evola and Metternich to this bowl of water for hours now, how much longer until it turns reactionary?
Which is exactly why this should be presented as a breakthrough in physics with the standards of verification and publication used in physics rather than announced as a way to propel rockets. Using the standards of a breakthrough in physics, they have an anomalous experiment. Now they need to replicate it under more idealized conditions and then we'll evaluate whether to give them a Nobel Prize. Almost certainly this anomalous experiment will turn out to be an experimental error or misinterpretation since the theory of conservation of momentum they are claiming to violate is so extremely well corroborated.
True, but of course, since the EM drive would not have that limitation, it would be able to theoretically attain those stupendous speeds because it will never need to worry about running out of reaction mass and would be able to accelerate for much longer.
Of course, I do think energy will be the limiting factor and will probably stop this from being an accelerate forever drive. Solar is fine and all, but is probably not going to recharge a ship on an interstellar trip enough to refill the batteries needed. You'll need a reactor and nuclear fuel to make a trip like that. Still much better than gigantic tanks of fuel, or massive amounts of solid fuel. Not to mention a lot less complex of a system.
So, it would be a big deal... if it's real. I have to admit, I didn't think it would get this far, but it's still a long way to go before this has a solid theory behind it, let alone becoming a fully operational device. I'm still hopeful but extremely skeptical.
The CMB is 3 Kelvin, there's got to be somewhere that it's only 2 K, right? Right? ;)
Well it is certainly going to be a novel device, but whether it is merely a parlor trick based on a clever application of known principles or entirely new science, is up in the air.
The problem is that we now have devices that seem to do the thing the first one did, but we still don't know that the device truly works on the principle suggested. There could still be something making it *seem* like it works that way, but it was something else all along.
The "propellant" is the microwaves, which carry momentum. They don't have to have _rest_ mess, but they still are a measurable propellant.
> As an added added bonus, such a drive would accelerate faster at a given thrust, because of the absence of reaction mass.
If only they didn't require an actual motor, or storage system for the energy for the microwaves. Since the maximum _chemical_ energy available in batteries is quite close to that of a good chemical propellant, it's only a big benefit if the energy for it comes from elsewhere, such as solar cells or a quite large nuclear power source. And if you have low mass space based solar cells, you can use either a solar _sail_ based system, or a transmission base to propel target spacecraft with a larger, more stable microwave source.
And where would the colder place be to vent that heat?
Just pop up a little lead umbrella so there's a shady spot.
Don't disappoint your bird dog. Go to the range.
The problem is that the explanations that we can get our hands on are so obviously problematic. Take the simple Newtonian mechanics diagram in the original post. They seem to be implying that the radiation pressure on the front of the cavity is larger than the radiation pressure on the back. That is fine. If that is the case, then there is a transfer of momentum to the radiation field. Where does this momentum go? If it goes out the back, then this is a simple and well understood phenomena that isn't powerful enough to propel a rocket. Any flashlight is a EM drive...photons out the back, momentum away from the light beam. It is just not an efficient way to turn energy into momentum. But they are claiming that some net momentum is produced without any photons out the back. And that is simply impossible without overturning Noether's theorem or establishing a way for space-time to be inhomogeneous on the scale of the spacecraft. It is really easy to get stray and reproducible momentum sources (see the Pioneer anomaly). It is much much harder to replace well established fundamental physics that is derived from principles as simple as the homogeneity of space.
Have gnu, will travel.
Looking at this another way:
When LHC were looking for the Higgs boson - a particle entirely expected by modern physics - they required a five sigma signal before they were satisfied that they had really found something.
This is a result not only entirely unexpected, but contradictory to almost all known physics. A two sigma (NASA) and three sigma (Germany) signal is not remotely enough to be convincing. At best it is convincing enough for someone to spend the money to further and better test it.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
If this data were at all convincing and held up to review, we wouldn't be reading a second hand report from Hacker News Magazine. This would be the cover article of Nature or Science. The editors would be fighting to have it.
The microwave photons don't exist the waveguide, it's a sealed system with nothing ejected - no particles, no photons, nothing.
This is why people are so surprised, there is nothing external to exchange momentum with.
Photons have momentum, but they don't have mass. You don't technically need mass, just conservation of momentum. The key is that the thrust produced that way is very small indeed, and that's apparently not the mechanism of this drive.
Socialism: a lie told by totalitarians and believed by fools.
There was a similar set of claims roughly 60 years ago for the "Dean Drive" a "reactionless drive" that did not seem to use propellant. To casual review, and letting it push your hand, it seemed to work, and a great campaign for research and to ignore the sceptics of the time was headed by John W. Campbell, the editor of Analog magazine. Analog was, and remains, a science fiction magazine specializing in hard science and science fiction based on it, and it had many real scientists as readers and contributors, so the Dean Drive received quite a lot of attention.
The Dean Drive has since been pretty thoroughly debunked as an "oscillation thruster", a device that relies on tuned "slipping" on the floor it rests on to creep forward and even to provide a modest thrust, _pushing against the floor_. The designer was never willing to allow a full "pendulum" test, or careful testing outside of his own workshop, and there seem to be dozens more of similarly patented "reactonless drives". The ones that work at all also seem to be "isicllation thrusters", pushing against the floor or the mehanism in which they are mounted.
They are not ejected from the thruster so are not propellant in any traditional sense. That means you can potentially use it in places where you don't want to be spraying people nearby with radiation, like on a hover car!
That's what makes this thruster so special, it's a sealed, closed system and there is nothing external to exchange momentum with.
I've been following this invention for years; since the first announcements from Shawyer through his being trashed by various physicists and wanna-bees, through his redemption through work in China and NASA. It used to be very difficult to get information, but since the burst of activity on the NASA Space flight forums, there's now too much information to digest, especially for someone like me who only has an undergrad level of schooling in it. If you want lots of details and discussion, check it out - but please don't post unless you really know what you're talking about, as there's already been a hell of a lot of noise. http://forum.nasaspaceflight.com/index.php?topic=37642.0
Conservation of momentum is more than "new physics". It's quite fundamental, thanks to Noether's Theorem: conservation of momentum is mathematically equivalent to "the laws of physics don't vary with spatial coordinates", that is, the X, Y, and Z axes can be "zeroed" anywhere, the choice of coordinates are arbitrary as long as their consistent. The universe would be a very strange place indeed if this weren't true, and furthermore we'd have noticed by now.
So, whatever's going on here, momentum is being conserved. Just how that's happening is the curious bit. It wasn't obvious until the early 1900s that light had momentum - maybe there's something else we're missing, or maybe this really is an actual "warp" drive that locally changes the metric of space (in a way different from GR) and momentum really isn't conserved. Somehow I doubt the latter is true.
Socialism: a lie told by totalitarians and believed by fools.
It's one thing to question the very preliminary theory of operation for the thing, it's quite another to demand that it is doing nothing just because it would be inconvenient.
My gut feeling is that whatever it is, it won't violate conservation of momentum.
You just need to route it through the rear deflector dish. Everybody knows that deflector dishes provide limitless levels of amplification under all circumstances.
If it is a parlor trick, it will be more accidental than clever I suspect. Even that would teach us something new.
You just gotta also have solar cells pointed forward to start recharging the battery as soon as you start approaching the star you're headed towards.
"Once you fire this husk of metal, it keeps going till it hits something. That can be a ship, or the planet behind that ship. It might go off into deep space and hit somebody else in ten thousand years. If you pull the trigger on this, you're ruining someone's day, somewhere and sometime....That means Sir Isaac Newton is the deadliest son-of-a-bitch in space."
"You saved 1968." - Ms. Valerie Pringle to the crew of Apollo 8
"The Skylark of Space" by E. E. "Doc" Smith?
The bud guy tries to kidnap the protagonist's fiancee, she kicks a goon into the controls which launches the ship straight up at ~10G. When they wake up they're out of copper and being pulled into a black hole, and her engagement ring was used in their last-ditch effort to avoid it.
Imagine all the burritos that could be heated up with this.
It's a radio transmitter feeding a closed waveguide. One has to ask: why haven't we seen evidence of radio transmission providing thrust before, when it's been feeding an open waveguide?
Bruce Perens.
but the approximations keep getting better
For outer system stuff you'd use a nuke.
"Fuel" in terms of energy isn't the problem in a rocket. The problem is the requirement to haul around reaction mass: stuff to throw out the back. If you don't need to do that, the tyranny of the rocket equation goes away and space travel suddenly becomes a much different proposition.
What, like this? http://spaceref.com/news/viewp...
The cheese stands alone...
I know, I'm just hoping. :)
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
Creates a gravity well and then falls into the dip.
Warp space, like gravity, fall into the well.
Well, it took 20 to 30 years (depending on POV) before Unix became the accepted OS. :) I can't think of one right now, but there have been many scientific theories and experimentally proven technologies that didn't get any love for decades. I'm not sure how difficult it would be to build one of these experiments, but they don't look that difficult from the tiny pictures I've seen. So I suspect that there are several folks right now trying to build a higher power version in their garages, and planning to pump a lot more power into the rig to see what happens. The maker types are less interested in getting the official scientific stamp of approval than in making something 'go'. So I'm optimistically awaiting the first hobbyist version that is hooked up to some supercapacitors and gets a megawatt jammed through it. Maybe it'll blow up, maybe it'll work, maybe it'll do nothing.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
So a Thorium-based molten salt reactor fuel cycle, whose power levels can easily be throttled up and down (or even off), providing a few (hundred, thousand?) megawatts ... :) Or someday fusion or antimatter ...
Thorium is nice because it's only minimally radioactive, can be stored in huge piles without getting 'hot', and won't sustain a reaction without encouragement - hence throttling ability.
I think a ship with a multi-megawatt Thorium reactor could carry enough fuel to run for 100 years pretty easily.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
Bang! thank you for saving me from my foggy memory :)
I tried looking up anything from Heinlein that fit my memories and couldn't find a trace, read a summary from wikipedia on Skylark series and it did not sound familiar, but you hit it dead on.
Wherever You Go, There You Are
Except solar panels lose power over time.
Not nearly as much as the haters assert.
Plus if you're moving away from the very star powering your craft, well then "forever" is not as long as you'd like.
If you are moving directly away, a solar sail would be more efficient.
Learn to love Alaska
Photons have no rest mass. Their mass is entirely their energy. They do have mass.
This isn't new. They had to correct for Pioneers microwave thrust. Heat thrust is the accepted explanation for the Pioneer anomaly.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Every post here are ignoring that there's THREE types of engines they are talking about. An ion thruster has reaction mass and expels atoms rearwards, i.e. solid fuel. It may be able to scoop this fuel up, but yeah, it's a standard engine.
A photonic rocket does not use reaction mass, and expels massless photons, i.e. radiation. You simply heat something, and the heat emissions generate opposite thrust. This generates thrust as photons lack mass but do have momentum, relating to the Planck length. The problem with photonic rockets is that this is REALLY REALLY LOW. Quoting Wikipedia: "If a photon rocket begins its journey in low earth orbit, then one year of thrusting may be required to achieve an earth escape velocity of 11.2 km/s if the vehicle is already in orbit at a velocity of 9,100 m/s"
The EMdrive does not require reaction mass, and simply expels microwaves which are kept in a resonant mode inside a chamber made of copper. The theory is that they basically push against _something_ like irregularities in space, or a virtual quantum plasma, or whatever. Remember that the casimir effect is already mainstream science - pairs of virtual particles appear and disappear - so there's at least something weird with space itiself. But anyway, it's similar to a photonic rocket in that it doesn't use reaction mass, but far, far more efficient and thrust-generative based on early signs.
Even if it's negligible, if it's greater then zero then sone very fundamental things we thought we knew about the world are wrong.
When all you have is a hammer, everything looks like a skull.
I'm with you man, but this was exactly the same thing that people said when NASA confirmed the results. I was with you then too. Skeptisisism and all that.
The fact that the Germans now have also confirmed this is pretty huge. I'd say this moves out of the 'anomalous experiment' territory and more into the 'can we devise more and newer experiments to understand what the flaven is happening here' zone.
I wrote a post about this above. 90% of the posts here are clueless.
Ion engines use reaction mass you have to carry with you.
Photonic rockets, what you ask about, use radiation, which still generates thrust because radiation has a Planck-sized amount of momentum, and exert this thrust on their emitter. Problem is that it's REALLY LOW. Like, so low that using it for propulsion anywhere near a gravity well is pointless.
The EMdrive is similar to photonic rockets in that it's reactionless and generates microwaves which are kept resonating inside a chamber, and it's theorised that they push against a non-flat space time or virtual quantum particles or whatever. Although the initial thrust detected was tiny, it is FAR HIGHER than photonic rockets.
One wonders what kind of educational path leads someone to wonder if ions have mass... Jesus wept.
It was created by an independent inventor in the UK. It is insulting to all of science to act as though a large organization like NASA is capable of breakthrough physics when literally all breakthrough physics has come from individuals.
"Modern physics is never incorrect"
That's religion not physics. Quantum Mechanics is like the scientology of physics. Clearly disprovable with simple thought experiments, but each time they need to ignore something (e.g. violation of causality) they do so like brainwashed zombies. i.e. its flat wrong and provably so.
Some science e.g. String theory gets silently ignored till it fades away then forgotten about.
You realize that Einstein may be wrong? He's become sort of a god or prophet figure, but that doesn't mean he was right.
Question everything, re-examine everything. in the light of new information is what science is.
ANY non-zero amount of thrust requires reaction mass, even if the amount of thrust is 'negligible'. Sometimes the reaction mass is stored externally (e.g. light sails), sometimes it's a planet (orbital magnetic thrusters) but it's always there.
Either no thrust is being produced or there is reaction mass. You just have to find out what it is. If the reaction mass is not sufficient to explain the thrust, then it's bunk. Plain and simple.
A fool and his hard drive are soon parted.
s/the Germans/one German on the record as having an interest in discovering exotic physics/
Until you travel at 0.7c and you discover the batteries are dead because solar isn't working at this speed so you cannot slow down.
At that speed could you point the solar panels towards the destination and collect ambient star light with greater than normal efficiency?
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
A propulsion device that provides thrust without using reaction mass would be an earth-shattering DEVICE. Launch it into space, strap it on an asteroid or piece of iron or whatever, accelerate out to a few lightyears at relativistic speeds and then come back...and don't slow down on the way.
the choice of coordinates are arbitrary as long as they're consistent.
FTFY
I would imagine that if you have a strong inhomogeneous magnetic field, you could rip out particle-antiparticle pairs, and move them as a group before they recombine, in which case you've exerted momentum on massive particles, independent of the fact that the momentum of their individual reaction is conserved. I can only picture this working though if you ejected the particles out the back. The contraption is apparently entirely closed.
Sounds similar to the Poul Anderson book Tau Zero.
It should be possible to construct a relatively low cost probe, making use of this new EM drive and the interplanetary transport network, to test this new concept. First, use the aforementioned interplanetary transport network and gravitational slingshots to place the probe on a solar escape trajectory. If the new drive actually works, then we should be able to, over a period of years and decades of interplanetary and ultimately interstellar cruising, to detect the acceleration of the probe as the EM drive continues to provide thrust in the absence of chemical propellent or anything to "push off against". The initial experimental results, both promising and controversial, seem to be enough to justify the cost of such a real world test. NASA ought to put together a proposal and budget a modest amount for this mission.
Acceleration is limited as much by available energy and limitations of materials as by the propellant. One can in theory shoot out a few particles at close to speed of light and accelerate arbitrarily fast. Or just shoot out lots of photons in one direction and move around "without propellant". This new drive has to not just work, but be more efficient than anything else we know. Else, it might well have some interesting science, but not be practically useful.
Photons have inertial mass. They just don't have rest mass. Although has anyone ever observed a photon at rest? If the state never occurs then I'm not sure I understand the point of positing a 'rest mass' and claiming that photons wouldn't have any if they could somehow be stopped. If there is no experiment through which you can show that a photon does not have rest mass then I don't see how one can make that claim. We would just like to believe they have no rest mass because that is what is consistent with current theory.
Quite an experience to live in fear, isn't it? That's what it is to be a slave.
'MURICAN education NUMBAH ONE!
...rear deflector dish...
I like sound of that. It accurately describes the shallow dipped lead plate that they will install at the back of the ship to bounce the microwaves off of, without a lot of techno mumbo jumbo.
Suborbital [spaceflight] is the special olympics of spaceflight. - Rei
hey, that's recycling too, right?
It's not like you'll be around to see the dead batteries after you hit a mote of dust at 0.7c.
History is replete with examples of commonly accepted physical principles undergoing revision in response to unexpected discoveries. I expect, along with nearly everyone else, this is the result of bad experimentation. But you never know.
Its a lot more complicated than that. ion thrust, photon thrust, em thurst, etc are nothing new. But this appears to be.
Imagine a closed plastic box that has a propeller attached on the outside. You put it in water, turn it on, and it moves in a direction. Common, simple, normal physics.
Now fill that box with water, put the propeller on the inside, and turn it on. Does it move in a direction? Of course not.
From what I understand, replace the propeller with microwave generator and for certain shapes of the closed box, the thing appears to move very very little. So this is the controversy, is it really moving or is it just a measurement issue where the micro thrust is within the measuring instrument's margin of error.
If it is really moving... WHY? That is ground breaking and it opens up a new arena in the field of physics.
> Hacked Magazine reported that a group of German scientists have confirmed the EM Drive ... ... in 1944 and have been using it ever since at their Neu-Schwabia base in the Antartica to power the Reptile Reich's Vril and Thule flying saucers. In other news, the Pentagon has classified all documents pertaining to Admiral Richard E. Byrd's 1947 southern naval aviation expedition for a further 100 years, in response to a recent FOIA request filed by Iron Sky AG and the Hollow Earth Society of America.
(By the way the Slashdot webform capthca for this posting is "fantasy". Apparently the publisher subscribes to the theory of ostrich's denial efficiency!)
I had to look deeper to see that you are correct. There _have_ been several NASA published designs using microwaves or other EM for ordinary thrust, I'm afraid I thought the original article concerned one of those.
On review, as I mentioned elsewhere, I'll bet that this is really a "Dean Drive". The Dean Drive never worked well outside the designer's workshop, was never tested properly with a basic "pendulum" test, and seems to have been a basic "oscillation thruster": it interacted with the floor under it to provide net thrust. That would mean the system is not really "sealed", it's interacting with its environment in some subtle way.
From the description at http://motherboard.vice.com/re..., I'd guess EM interaction with the walls of the stainless steel vacuum chamber. And one of hte people I'd want to review the experiment would be James Randi, who's been helping debunk "mysterious mental force" claims for decades, and has a professional magician's eye for misdirection and sleight of hand.
It's a so called reactionless drive. Assuming it works that is. We are talking about the realm of sci-fi here.
Dr. Martin Tajmar seems to have a peculiar interest in anti-gravity with superconductors though. So I wouldn't put a lot of faith in these experiments.
Just put the damned thing in a micro-satellite and test it. Then we will see if it works or not.
Lets get one thing clear. They have shown no such thing. This is the 3rd non peer reviewed "look at my microwaves" report on this device. The link is to some internet magazine. This will turn out to be just like every other perpetual motion device. Experimental error, and mistakes and just straight out sloppy experimental work like the last 2. We know EM theory and practice very well and right now we have fans of result finding what they want to find.
Also any zero propellent drive is also an over unity device. Easy to prove.
If information wants to be free, why does my internet connection cost so much?
I have no idea what your saying. But photons do exist in the waveguide. A perfect metal, and indeed many real metal will prevent almost all photons from escaping in many cases. But not all.
If information wants to be free, why does my internet connection cost so much?
Don't hold your breath. Just like the nasa guys, even they way they publicise this should put your hinky meter all the way to red. This is not just a violation of momentum, but of relativity and energy conservation. And its is yet another sloppy experiment with sloppy reporting. And like many cases like this before, it will turn out to be nothing. I bet you 1 years salary.
If information wants to be free, why does my internet connection cost so much?
How is this any better than an ion thruster?
What part of "without using reaction mass" did you miss?
Watch this Heartland Institute video
" as long as their consistent"
That is NOT how you use the word 'their'.
Things like black-body emission would be very different if photons had mass. There would be a threshold energy needed to produce one, and that's not what we see. Unless you're happy to throw away the conservation of energy, in which case you might as well throw away just about all physics.
James Randi knows squat about anything twisted to the em drive. He's a very clever guy, but not the right guy for this particular case. Nobody appears to be attempting to fool anyone. People are getting consistent experimental results. Those results just happen to be unexplainable using current physics (maybe).
I think the point is that even accounting for waste heat (which is the kind of photons that has to escape eventually) doesn't account for all the observed thrust. So either there's a measurement error, or something else must generate extra thrust.
Ezekiel 23:20
At 0.7c, you might be able to somehow capture the hydrogen atoms that keep hitting you and harvest their kinetic energy, which should amount to something like 12 kW/m^2 of your ship's cross-section at these speeds in the average interstellar medium of about 1 hydrogen atom per cm^3.
Ezekiel 23:20
Read the reports. There is no extra thrust. The null experiment got the same flipping results. AGAIN.
If information wants to be free, why does my internet connection cost so much?
And yet possibly not so simple. You stated the theory that is being challenged. Now I don't hold out high hopes because that theory fits so well, but that doesn't mean it is impossible the theory is wrong or incomplete.
It's not impossible that the theory is wrong. It's just so remotely improbable that even considering it as a possibility is almost certainly a waste of time. Why are some people so eager to throw out established science, when it's far, far, FAR more likely that it's an experimental error or miscalculation?
We saw this with the bogus and unnecessary 'explanations' for the pioneer anomaly, the FTL neutrinos, and the e-cat device. There is no shortage of contempt for science, it seems.
A fool and his hard drive are soon parted.
EVERY heavenly body circles the earth, even if the apparent motion isn't linear. Sometimes it's on a different celestial sphere, sometimes it's on a different epicycle, but the Earth is always at the centre.
Either a new planet doesn't really exist, or it follows its own epicycle. If nested epicycles are not sufficient to calculate the path, then it's bunk. Plain and simple.
A car moves by pushing against the ground.
A rocket engine works by throwing fuel in one direction so the rocket goes the other way.
A boat prop works without throwing fuel overboard by accelerating the stuff around it.
This gadget appears to work inside a metal box.
That should eliminate the ability to push, throw or accelerate classic stuff (matter) outside the box.
Yet, the whole box appears to want to move. Curious.
It might be pushing against some external field.
Presumably, the experiments eliminated the Earth's magnetic field.
Or it might be accelerating something that can go through the metal box.
Or perhaps these two effects might be the same thing?
If it is real, it may teach us something new about how things work.
That may turn out to be more interesting than having a new kind of space drive.
There is a place for scientific skepticism, and what you are saying is all well and good. And pretty well articulated too-- that's unusual among the pure science worshippers.
But scientists do not advance our technologies. That is done by engineers. And engineers are grubby guys who don't care much about how a thing works, so long as it does work in a reliable way. That pragmatism is why we've got bicycles even though the physicists are still scratching their heads over the self-correcting stability of these elegantly simple machines. (Hint: it has very little to do with "gyroscopic forces", and seems to have a lot to do with the "trail" that has been engineered into the steering geometry).
If we attain a working deep space drive before we understand exactly how it works, then most of us will applaud. We need the Edisons as well as the Einsteins. Even though as Tesla said, "If he had thought smarter, he would not have had to sweat so much."
Will
I don't see any problem with this kind of reactionless drive. It can work without violating conservation of energy.
The apparent violation of conservation of momentum is due to a failure of the observer to recognize the true size of the system involved. If the mechanism is drawing on solar power, then some part of the continuing loss of mass of the Sun is part of the system, even though that is somewhat spatially distant. If it is powered by an on board fission reaction, then it is the reduction in mass of the fissioning material that is part of the system.
In all cases the energy of the universe is being conserved. The apparent breakage of the laws of conservation of energy, matter, and mass is all in the observer's head, through a failure to properly recognize the boundaries of the system.
Will
We're assured there's dark matter everywhere, maybe 5x as much dark matter as normal matter. What if these guys have found a way to interact with dark matter, essentially pushing on it?
It seems like dark matter has mass, and momentum, but it interacts poorly with regular matter. If you were pushing on dark matter somehow, it could just fly out of the chamber. Suddenly your "reactionless" drive is just another rocket that's using particles that happen to be around to push on.
However, if EM waves could interact with dark matter in any way, it shouldn't be "dark". You should see signs of interaction on cosmic scales or near very intense light sources like black holes, right? Or would the influence of such interaction be so small compared to gravitational redshift that it couldn't be noticed?
--PM
Seems to me that at relativistic speeds, ship time slows down or stretches out. So the chances of still being alive at point of impact are higher than one might imagine.
Will
And I agree, this evidence isn't yet.
The forces generated are currently just too small to trust, and within the realm of experimental error given that they're within an order of magnitude of the noise. I'll only start getting excited when they scale up to measurements which are at least a few orders of magnitude above the noise threshold.
One wonders what kind of educational path leads someone to wonder if ions have mass... Jesus wept.
Realistically, the average person on the street does not know whether or not ions have mass.
"What the American public doesn't know is what makes them the American public." -Ray Zalinsky (Tommy Boy)
http://www.gutenberg.org/ebook...
Creates a gravity well and then falls into the dip.
Isn't that the way Robert Lazar's flying saucer was supposed to work?
"What the American public doesn't know is what makes them the American public." -Ray Zalinsky (Tommy Boy)
That's a Bussard ramjet, right? https://en.wikipedia.org/wiki/...
I think it's theoretically possible, but you some technique a lot more efficient than a Penning trap.
I wonder if the mass of the device changes after operating a while. Lets say the change of mass in the larger back plate is bigger than the the change in the smaller one, that would respect the conservation of momentum, and explain the thrurst (thrust will arise from the need to accomodate the difference of mass in the plates).
I don't think you're paying attention to the credentials of the last two batches of testors. This isn't sloppy work. Harold White (NASA) is highly credentialed and esteemed by his peers. The German team in particular is well known for being a bunch of pedantic twits able to rip apart experiments for their faulty methods. They haven't given up on that chore, but their initial conclusions report an inability to find fault in the experiment and are able to comparably reproduce the results.
This device also doesn't have to violate physics, just our current understanding of it. The quantum world for instance while reasonably modeled is largely just that. A collection of models that fit observed behavior. Who says microwaves cannot interact with something from that world? One of the ideas tossed out there (by White IIRC) was that they were pushing against "virtual particles"
Two of my imaginary friends reproduced once
You say that the apparent violation of conservation of momentum is a failure to recognize the true size of the system involved. Then you give two examples of conserving energy, a considerably different thing. What is the size of the system involved that conserves momentum?
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
'Tajmar has an interest in exotic propulsion methods, including one concept using "negative matter."' -- is this what they mean by "it matters not" ?
I read them. Yea its really sloppy. Credentials don't give you a free pass. Measuring forces that small without a proper vacuum or proper controls or just plain ignoring the results of the controls. Even this one has the *same* force for the control where there should be none and yet won't conclude no detectable force. And also the german "team" have a patented anti gravity device.
There is a reason almost none of the this gets published properly in science journals (hint newscientist is not a science journal, its a magazine and a shit one at that.), not such good credentials. It is plain sloppy.
For the device to work, it must violate conservation of momentum, Maxwell's equations, Quantum physics, relativity and conservation of energy. Oh and somehow 400 years of experiments are wrong.
I bet one years salary that this doesn't work as advertised. (I earn about 120k pa)
If information wants to be free, why does my internet connection cost so much?
Go back to the books and read up on conversion of matter to energy, energy to matter, and momentum as a type of energy.
In Einstein's model of the universe, the "law" is the conservation of matter and energy. In 7th grade physics there is talk about conservation of momentum in some instances (like billard table models, sans friction), but that is physics for babies. It is even ignoring the conversion of momentum to heat that always happens since billards is never played in a vacuum on a frictionless table.
Will
That energy is called drag. In fact it has been shown that the Bussard ramjet won't work because of that drag.
If information wants to be free, why does my internet connection cost so much?
but then IANAP. So there may be things I don't know about that render the following reasoning untenable.
Black holes "radiate" via virtual particles, whereby a virtual pair comes into being close to the event horizon. One of the pair falls into the black hole, while the other goes free. Thus the black hole "loses" a particle.
If you could somehow make sure the black hole "radiates" only in one direction, you could propel the black hole in the other. In inverse proportion to the masses, obviously.
So if virtual particles are created by the microwave drive somehow, then one particle stays with the drive, pushing it one way, with the other particle going in the opposite direction. Again it's in inverse proportion. You just need a whole lot of them, all going in one direction.
This is analogous to New Horizon's EM drive, only there you use xenon atoms as propellant, which are a whole lot heavier. The xenon atoms go one way, the craft goes the other. Energy is needed to form the xenon ions, propel them in one direction, and recombine the ions with electrons just before they leave the craft.
Seems to me this doesn't violate any laws. Momentum is conserved, starts with zero, ends with (a sum of) zero. Energy is required to keep the virtual particles going in one direction (and to accelerate them, I assume). So you still need energy; what you don't need is propellant. In New Horizon, the supply of xenon is limited. With the new drive, the supply of propellent (virtual particles) is unlimited.
Unless, like in Charles Sheffield's Novel, "Godspeed," the vacuum store of virtual particles is a resource that can be used up (if my memory is correct).
It's one thing to question the very preliminary theory of operation for the thing, it's quite another to demand that it is doing nothing just because it would be inconvenient. ...
True.
If you have something that works, no theory is required to build one. People built things long before they invented the scientific method.
A good theory is -very- useful for improving things and making them more reliable. But it is not -required-.
Good job son, you sure showed that strawman who's boss.
IF you really do have a reactionless drive. You really do have a free lunch. It is a over unity device.
The output power of a device traveling at speed v with force f is p=fv (work per unit time=force x distance per unit time). if the power force coefficient is k such that f=kP where P is the input power. Then once traveling at speed v=1/k output is higher than input. Your getting free energy. You can generalize this for total energy and arbitrary frames of reference pretty easily.
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Why are some people so eager to throw out established science, when it's far, far, FAR more likely that it's an experimental error or miscalculation?
Because it is not global warming :D
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I agree.
Thorium is nice because it's only minimally radioactive, can be stored in huge piles without getting 'hot', and won't sustain a reaction without encouragement - hence throttling ability.
The same is true for Uranium. Since a Thorium fuel cycle *burns* 233U it also still has decay heat. Throttling down can be done, but heat dumps are required. Not hard to do since even conventional generation often needs that. Thorium is not magic and homogenous reactors not restricted to Th.
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Seriously??? That is just sad.
Particles with mass move slower than the speed of light, experience the passage of time, and can thus change state (e.g. decay). Mass-less particles move at the speed of light (when in a vacuum), do not experience the passage of time, and thus cannot change state. Photons are clearly the latter.
Oddly enough, whether a kind of particle has mass can change over time, and it's thought that all particles were massless in the very early universe. The reason the Higgs Boson discovery was exciting was that it confirmed the idea of a particle changing from mass-less to massive in the early universe (the Higgs Boson itself is pretty dull).
Socialism: a lie told by totalitarians and believed by fools.
Perhaps more importantly, a good theory comes from further building and testing. Denying that it does anything and shelving it means no theory is likely ever happen.
Also any zero propellent drive is also an over unity device. Easy to prove.
If such a thing has actually been discovered, the very likely result is that it's neither "zero propellent" nor over unity, but instead has something being emitted that we don't understand.
For example, one could imagine an engine that seemed to have no propellant, but was in fact creating and emitting dark matter. On the lab bench it would be consuming energy that would be going somewhere mysterious (e.g., not heating up enough for the energy inputs), generating measurable thrust, and having no measurable propellent. Obviously that's not what's going on here, but something like that (emitting a propellent we don't know how to measure) would be the only rational explanation for any such device.
It's also theoretically possible to have a "warp" drive that produced thrust without propellent by altering the local spacetime metric. But this would not be "over unity", would be quite obvious as it would be turning local space into a lens, and likely isn't actually possible, for all that the math allows it, as you'd think we'd have seen evidence of it by now.
I guess "negative mass" drives also aren't ruled out yet, which also would have no propellent and while they are perpetual motion machines, they aren't "over unity" due to a technicality. Negative mass seems even less likely to be actually possible, despite the math allowing it, given the lack of evidence of its existence.
Socialism: a lie told by totalitarians and believed by fools.
What? Do you say they had this thing since pioneer?
Now, what is all the fuss then.
Logisches denken.
Color me skeptical. And remember the recent "faster than light" hype from cern. Turned out to be a rusty electric contact.
But all the stupidos were salivating and modded me down.
And considering the number of engineering catastrophes that Germany is facing right now... That doesn't mean what it used to mean
Let's rub this into the treehuggers: ONLY nuclear reactors are any good for deep space flight.
But yeah, we all know the bejesus must be scared out of the sheeple to keep the 99% idiots under control.
Yeah, for comintern definitions of " far".
You're perfectly correct that MSRs don't actually run on Thorium. That's one of the reasons they'd be an effective nuclear waste burner.
The advantage that MSRs have over pellet/pebble/rod-based reactors is that when you throttle down, an excess of xenon-135 builds up. This is a neutron poison and damps down the reaction, making it hard to throttle up again until it's decayed (that takes a while. The Half-life is 9.2 hours). Attempting to push through the xenon poisoning by setting the power to 11 can be catastrophic - this is what took out Chernobyl. http://hyperphysics.phy-astr.g...
Because the fuel is not sealed into capsules in a MSR, the Xenon can be extracted into the thermal expansion headspace just before the circulation pump by sparging it (https://en.wikipedia.org/wiki/Sparging_(chemistry)). You need to do this to get helium and other gasses out anyway so it's not a big deal. The end result is that throttling is fully linear and because MSRs don't suffer from steam voids if you snap to full power, the reaction rate can track load at least as fast as a hydro plant and probably as fast as a OCGT plant.
I was going to write a lot more but given this is about space applications it's probably irrelevant. You'll need a thorium blankie for your U233 MSR reactor or you'll run out of fuel eventually. Having it soak up stray neutrons is a good thing in what would probably be a relatively confined space.
Ignorant. The law of conservation of momentum is a law that can be precisely formulated in mathematical terms and ever since it was, no violation of it has ever been observed. Not even a little. Further, it has deep theoretical underpinnings that would mean a universe that violates it would look very very strange indeed and probably nothing like our Universe. By comparing it with the theory of epicycles you're simply showcasing your scientific ignorance and stupidity.
A fool and his hard drive are soon parted.
I don't get it.
A fool and his hard drive are soon parted.
A propulsion device that provides thrust without using reaction mass would be an earth-shattering DEVICE.
Or a helium balloon. The only problem is that it stops "providing thrust" when heavier air stops moving below it.
How exactly would peer review work in this case? At this time the question is reproducibility of results, i.e. more experiments.
Are you for real? Your physics leads to P=P. Momentum and energy are two different entities (hence two names).
This is my third and last cowardly reply to you. I do not like you.
Because all scientists are clearly infallible which climate models (read the papers!), but dark matter, conservation of momentum/energy then obviously all scientists are total idiots.
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Little p and big P. Really that is the math. Do it yourself. Reactionless drives are *always* a over unity device in some characteristic time.
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It's also theoretically possible to have a "warp" drive that produced thrust without propellent by altering the local spacetime metric.
Err not really. You have to violate a bunch of things widely held to be true for real mass configurations. Also you need negative mass, which doesn't exist even theoretically, oh and more mass energy than the entire universe. Finally it is totally causally disconnected from the rest of the universe.
Just because i write down math does not make it a valid prediction.
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s/the Germans/one German on the record as having an interest in discovering exotic physics/
If you want to be nitpicky - he's Austrian.
Of course news about a fake are Fake News.
Strong words from an AC.
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Peer review at this level is. Did you do a reasonable experiment. Have you identified errors etc. The NASA ones did not even pass that.
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The impression I get is that there is no shortage of idiots who consider themselves to be more knowledgeable than climate scientists. And they often whine, like you are doing now, about how climate scientists 'consider themselves infallible' which is not true at all.
A fool and his hard drive are soon parted.
Err not what i meant. I mean that a lot of ppl on /. think climate models etc are set in stone and we know how its all going to shake out. Nothing about the models or scientists. While at the same time they will armchair their way into a dark matter discussion on how clearly stupid all scientist are. "free energy/momentum" devices seems to another such topic where clearly scientists are the stupid ones, and reading a wiki is out of the question.
Also you need negative mass, which doesn't exist even theoretically, oh and more mass energy than the entire universe
Are you thinking of a wormhole, not a warp drive? I'm not talking about a Star Trek FTL drive, but instead a device that warps space, just like gravity does, but asymmetrically. I don't believe it's possible either, but it's still allowed by accepted physics, and it wouldn't require lots of mass.
I don't think we'll know enough about this concept, or about negative mass, to rule them out until we finally understand how mass is quantized, or, rather, where rest mass comes from in the first place. Maybe when quantum gravity is finally understood there will finally be an explanation for rest mass, but maybe it's even further down the road.
Heck, we can't even measure the rest masses of quarks accurately -- not even one significant digit in some cases -- let along explain the values There's lots of physics left to be done there.
Just because i write down math does not make it a valid prediction.
The math of modern physics has been shockingly predictive. All sorts of crazy shit has turned out to be true - so much so that people believed in String Theory for 20 years with no evidence whatsoever (and some still cling to that belief). Those people aren't stupid: "following the math" has a really good track record. It's best to keep an open mind until we get better theories.
Socialism: a lie told by totalitarians and believed by fools.
Ah, then I misunderstood.
A fool and his hard drive are soon parted.
Good grief, find a physics book and read it. Momentum is NOT a type of energy. The units are different even.
Conservation of momentum is easier to figure when you disregard things like friction. It isn't just an explanatory concept. It is NEVER converted to heat, since momentum isn't energy. What happens when we hit a billiard ball is that the planet (or a fair chunk of it) gets momentum opposite to the ball, although that's too tiny to notice (and, probably, to measure). Friction can cause heat, but that's a conversion of kinetic energy to heat energy, not momentum to heat.
"When you have eliminated the unacceptable, whatever is left, however improbable, must be the truthiness" - Holmes
This isn't new. They had to correct for Pioneers microwave thrust. Heat thrust is the accepted explanation for the Pioneer anomaly.
This isn't heat thrust; the EM Drive doesn't emit the microwaves.
Each experiment so far basically said "we measured a small amount of thrust... so small that we're not sure if we measured any thrust at all."
The theory behind these devices says that thrust will increase by orders of magnitude if a superconducting RF cavity is used.
So why not do that? The results would be unambiguous, for a change.
That that is is that that that that is not is not.
No i am thinking of a warp drive. The Alcubierre drive or space time metric in particular. It the sort of metrics that lead to closed timelike space curvature or whatever (its been a while), ie time travel. In all these cases various things are not conserved that are wildly held to be conserved, requires negative energy etc.
Sure math can be predictive. But that leads you in the direction of a experiment, it is the experiment that matters. I can get imaginary results for calculations for throwing a ball, that does not make the ball imaginary. Even more interesting is that we have fudged the math a lot in the past, because it works. Later mathmaticians make it more rigioirs. In otherwords we design the math to fit the universe we live in.
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No i am thinking of a warp drive. The Alcubierre drive or space time metric in particular. It the sort of metrics that lead to closed timelike space curvature or whatever (its been a while), ie time travel. In all these cases various things are not conserved that are wildly held to be conserved, requires negative energy etc.
Ah, sure, lots of things are called "warp drives" I guess. Yeah, that sort of drive seems wildly impractical for all sorts or reasons.
What I'm talking about is somewhat different: it's an asymmetric warping of spacetime in just the same (smooth and continuous) way that all mass distorts spacetime symmetrically, such that you "fall" in some chose direction. It doesn't require the same exotic material as a wormhole, but I think it requires soemthing equally exotic (it's been a while, but I vaguely remember there are 2 different kinds of negative mass).
Sure math can be predictive. But that leads you in the direction of a experiment, it is the experiment that matters.
No argument there. But if someone were really demonstrating a drive with unexpected properties, not just stage magic, that's an experiment worth repeating.
In otherwords we design the math to fit the universe we live in.
We do, but then we see what else that math predicts. Most of the really crazy-non-intuitive stuff in QM has come from very unexpected consequences of the math that later proved out in experiment.
Heck, the whole crazy idea that the universe once had an additional field that certain particles couple with, preventing change in spin polarity without energy input, but then that field "condensed:, and now those same particles can spontaneously change spin - that's all just seeing where the math led. Until the Higgs Boson was found, a big chunk of electroweak theory hadn't been directly confirmed by experiment.
Socialism: a lie told by totalitarians and believed by fools.
Violation of space translational symmetry? Changes the metric of space? I doubt both. I think its more of an experimental error by amateur engineers dabbling in experimental Physics.
I doubt both the studies but I am sure this will now attract enough eyeballs from many Physicists. I am sure we will soon hear more on this story. Stay tuned.