Can someone tell me the status of the EM Drive testing? I know it is controversial but the NASA Space Flight Forums aren't interesting anymore, kind of died since larger companies/countries got more serious about testing.
What are your thoughts on it?
Other urls found in this thread:
newscientist.com
emdrive.com
twitter.com
Em-drive seems pretty cool
Do you think the theory has validity? Exhaustless acceleration?
The Chinese claimed they had a working model.
Claims later retracted when they found errors.
If there IS an effect it's right at the limit of measurement in groundside apparatus. Hence, unsubstantiated rumors that both China and the US are secretly making tests in space where there are fewer disturbances and the force (if any) can accumulate to cause a noticeable change in a satellite's orbit.
Shawyer's "theory" is total BS. That doesn't necessarily mean the gadget's a fake but success would abrogate a couple of centuries of careful experimentation that say it can't work. Both momentum and energy conservation go out the window along with Special Relativity.
If there is a reaction, then shawyers theory can't be 100% wrong, just the explanation of it. that just means our model is incomplete. there could be forces we don't understand that have mathematical explanations, like dark matter and dark energy did
If you set up the geometry of the resonating cavity such that the group and phase velocities of the resonant EM modes are different --- if this is possible --- then you can convert to momentum space and examine the wavenumbers of the group and phase velocities. The momentum is [math]\hbar[/math] times the wavenumber and if you get two different momenta, then you can take their difference. The difference of two momenta is an impulse, as in "impulse power" on Star Trek. Totally feasible, seems legit.
One way to get a difference of two momenta is to have the geometry of the cavity such that there is emergent complexity between the group and phase velocities when the modes of the confined electromagnetic field travel toward the thin or wide end of the resonating cavity.
t. physicist
Shawyer's claim is that energy is conserved and (apart from losses) it can hover at constant altitude without power. But that would violate the equivalence principle; no power needed when hanging above Earth, but power needed to accelerate at 1 gee when somewhere between stars.
In addition, if input power shows up as KE of spacecraft, WHAT KE do you measure? You can't carry around a meter which tells you your kinetic energy. Velocity and kinetic energy only mean something when measured from an external object. And the only one which counts (observers on Mars, Earth, and Venus will say different things) is whatever you're pushing against. The roadway for your car, the surrounding medium for a ship or plane, the exhaust for a rocket.
Kinetic energy is meaningless without something to react against. The vacuum? That takes us back to Absolute Space and the luminiferous ether.
> it can hover at constant altitude without power.
I haven't read that claim -
"t. job description". That Veeky Forums shorthand for "I am a whatever?"
It's shorthand for "Written by an expert in physics."
newscientist.com
clearly states that the thrust (constant power input) varies with the velocity of the spacecraft. Which brings us back to "what velocity?" Thrust drops off as the craft continues to accelerate? That's absurd. Turn off the engine for a second and re-start with a re-set "zero point".
This is confirmed in the final paragraph of emdrive.com
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.
Energy is required only to accelerate, but not to provide lift when "hovering"
Addenda: Not sure if final paragraph meant "accelerate horizontally" or "accelerate vertically".
The latter is even worse. The Emdrive can counter gravity so long as it's not accelerating. But give it a one-time shove upwards and it should continue to rise indefinitely (gaining potential energy) without any increased power demand because the velocity is constant.
the final paragraph is referring to moving a car on terrestrial earth, if that matters.
If this works as advertised, could we then have hovering Command Carriers like in Deserts of Kharak?
a theory IS explanation
Shawyer's explanation for how the EM Drive might work provides for constant thrust, which means the EM Drive could be used as an over-unity device.
"Car" meaning something like what Luke Skywalker drove in the 1st (in order of production) movie? A car with wheels wouldn't need "lift".
Precisely. His claims are contradictory.
Energy conservation has to be violated SOMEWHERE!
How though? The moment it is cut from power it no longer would output thrust.
A over-unity device would self power while putting out thrust.
www.dtic.mil/dtic/tr/fulltext/u2/750554.pdf
tldr;
this is very old news
60 years old
Not using a radio frequency resonant cavity thruster/electromagnetic thruster with a microwave cavity, producing thrust from an electromagnetic field inside the cavity.
who cares it can still fly without the need for fuel
it does need fuel. Just not liquid / explosive fuel
>fly around the world without refueling
>momentum is the wave number times planck's constant
STFU you ain't a physicist if you confuse the squared modulus of momentum (a scalar) with momentum (a vector) in a problem where direction is so important.
A real physicist
Imagine a vehicle running along a railroad track. The track plays no role except that it's bolted to the Earth and removes any ambiguity about which reference frame we're using.
The vehicle has a reactionless thruster which produces a fixed N newtons of thrust while consuming W watts, regardless of the motion of the vehicle. OK?
The vehicle starts down the track. The thruster consumes power at a constant rate and, hence, accelerates at a constant rate. The power remaining it its battery drops as a linear function of time.
But its kinetic energy (which can be released by slamming into the bumper at the end of the track) rises as the SQUARE of time. Eventually, it must exceed the total energy which was in the battery when we began.
To put it another way, once the car is moving, we can apply electromagnetic braking (linear motor in reverse) and siphon off energy through the rails. If the braking and thruster force are equal the speed becomes constant. We can also feed energy from the rails into the vehicle to keep the battery charged.
If the velocity V is greater than a certain amount, the energy we harvest is greater than the energy required to keep the system going.
Over-unity.
This applies to ANY system whose thrust is independent of its motion. A photon rocket, the most energy efficient possible rocket (for rockets which eject mass, the mass counts as energy too) behaves this way too. But the "crossover velocity", the speed at which there's net energy gain, is the speed of light. Since we can't exceed that, a photon drive railroad car always loses energy (carried off by the drive beam.)
Any thruster more efficient than a photon rocket is, therefore, a Free Energy or Perpetual Motion, machine.
It works, but producers of classical space engines and fuel want to suppress it.
Same thing that happened with cold fusion.
This is what happens with science in countries ruled by free market.
If cold fusion works, why is China still surreptitiously importing coal from North Korea?
If Emdrive works (but is suppressed by Capitalism) why isn't China touting their bases on Mars?
If there's a profit to be made (and to hell with other people) why can't we buy Trump(tm) Fusion Generators or memberships at the Trump(tm) Valles Marineris golf club?
>muh perpetual motion machine
This might work in the vacuum of space, but here in Earth's atmosphere we have air molecules that siphon off some of that kinetic energy as irreversible work. Unless you are proposing a hyperloop meme apparatus.
Lay the railroad tracks on the Moon then.
It's STILL perpetual motion even in the absence of air.
All such experiments are set in Thermotopia; land of frictionless surfaces, weightless ropes, perfect insulation, ideal gasses, and Carnot Cycles.
One way to get get over-unity electrical performance would be through a process called "stimulated emission from the vacuum." Basically you would act on a vacuum phonon with the second quantization operator to create a particle. Perhaps the particle's kinetic energy (or momentum in the case of a photon) can be derived from the zero-point energy available to to the vacuum phonons (but is not generally available directly to the particle that is created with the second quantization operator.)
Classic Veeky Forums lol
I'm not sure what you mean. I mean [math]p=\hbar k[/math] where the tensor rank of [math]k[/math] is irrelevant. Which squared modulus do you refer to? Why do you refer to it? Are aware that impulse is a vector and if the difference of two quantities is a vector then the two quantities were also vectors? You criticism was not verbose enough for me to understand.
>zero-point energy
>Responding to an overpass dwelling hoboschizo
Any power plant requires a potential difference to work. Even if the vacuum energy was huge (and it's not, because the universe would immediately collapse from self-gravitation) we can't extract it because it's the same everywhere.
To get thrust you'd have to;
1) supply energy to raise a virtual particle (or two) into existence
2) give it a shove aft
3) recover the energy for re-use on the next particle
1) is possible, 2) is not, and 3) I'm not sure of.
well over-unity and EM-drive are two totally different things anyway. If EM-drive work with an over-unity power source then it works with a battery too. Also, "not possible" is usually not considered a valid refutation of allegations of a groundbreaking new technology. They said manned flight was "not possible."
It needs combustible fuel so that goyim don't suspect anything.
No, no, you obviously didn't follow the logic.
The battery is just to get the thing going.
If a constant-thrust-per-unit-power-regardless-of-its-state-of-motion device is possible, it can be used to BUILD an over-unity device.
Your other point is sort of like the "it's not possible to fly faster than sound" or "it's not possible to send men to the Moon". Both were fully known to BE possible centuries before they were actually done. (Whips and bullets go faster than sound. Isaac Newton showed an object, given the right velocity, could go to the Moon.) There were immense practical engineering difficulties and they MIGHT have been insurmountable. But they were always theoretically possible.
Physical laws cannot be broken. Ever. We may not know all the correct laws today but when new laws come along we can be sure that they will agree with all experiments which had been done to the point. Laws ARE, even if they're unknown and not recognized yet.
And there's an awful lot of experimental evidence (as well as theoretical justification) for the Conservation Laws. The burden of proof is on any one who wants to overturn an "accepted law". Any violation, no matter how small, will do it. But a demonstration is required.
We know you are a physicist. Only absolute newfags don't.
thanks everyone
i really just want them to fly one into space and turn it on
I don't suppose you'd write something like "Jonathan W.Tooker is obviously the world's most successful living physicist. He saw where the gaps were and filled them in. Other physicists for whom the gaps were insurmountable have successfully built their own things on the foundations that Jonathan W. Tooker laid for them. His research is summarized in his new book The General Relevance of the Modified Cosmological Model which is available free on online at vixra.org
Nah, I'd write "Jonathan Tooker is the court jester of Veeky Forums and his braindead ramblings from his hovel under the bridge are a refreshing spark of life in the void left by the death of Francis E. Dec Esquire."
"Also he's not god ololol"
zuma
"t." is a meme that started a few years ago, it's how Finns sign off at the end of letters, it's short for their word for "sincerely".
Thanks. Learn something new every day.
t. Grand Duke of Finland
Even if this thing does actually work, it is still more or less useless because you would need a billion niggawatts to produce any actually useful propulsion.
What type of degree would you need to work on something like EM drive? I mean, obviously physics.. but what about after that?
I'd assume the effect (if there IS an effect) is some aspect of quantum mechanics.
But I'd hold off specializing until there's proof it works. You'd be like a grad student in 1900 working to improve the sensitivity of Michelson-Morley so as to catch the "aether drift". There is no aether and no drift so you'd be doomed to fail.
Sawyer claims efficiency will improve if the cone is superconducting. So much so that flying cars will become feasible. So power consumption isn't the show-stopper.
As explained earlier though, the whole thing sounds less convincing than the technobabble on ST:TNG. If it doesn't work at all, no need to worry about efficiency.
>put magnetron on some tube that looks like an engine
>claim that device produces thrust
>measure 1/1000000000000000000000000000th of an ant fart of thrust on one of the world's most sophisticated devices
>years pass and zero progress is being made
>people unironically still think that the EM Drive might work
How can you be so retarded? Am I living in a meme world?
>photon rocket
>energy efficient
I don't think so, Tim
>Am I living in a meme world?
Afraid so.
Sadly.
You can't read Veeky Forums more than 20 minutes without figuring that out. :(
Some are idiots. Some are trolls and contrarians. And I swear I caught a Russian hacker here once, working hard to make sure Americans remain stupid.
All other types of rockets eject more energy (mostly in the form of mass) to generate a given amount of momentum.
Photon rockets use a hellish amount of energy to generate minuscule thrust. Chemical rockets dump tons of mass every second. It's just not as spectacular.
Think about it a bit.
>Am I living in a meme world?
But that's exactly it, user. That which is memed must come to pass.
bump
pmub
TLDR No, the EM Drive doesn't work. Newton is STILL THE KING!!!
Would this work, Veeky Forums?
yes
t. Physician
Alien plagiarism!
Cyrano de Bergerac thought of it first!
>>measure 1/1000000000000000000000000000th of an ant fart of thrust that pushes in the same direction regardless of which way the "drive" is facing, on one of the world's most sophisticated devices
That addition is important.
THE VISCOUNT: I'll treat him to. . .one of my quips!. . . See here!. . . (He goes up to Cyrano, who is watching him, and with a conceited air): Sir, your nose is. . .hmm. . .it is. . .very big!
CYRANO (gravely): Very!
THE VISCOUNT (laughing): Ha!
CYRANO (imperturbably): Is that all?. . .
THE VISCOUNT: What do you mean?
CYRANO: Ah no! young blade! That was a trifle short!
You might have said at least a hundred things
By varying the tone. . .like this, suppose,. . .
Aggressive: 'Sir, if I had such a nose I'd amputate it!'
Friendly: 'When you sup It must annoy you, dipping in your cup;
You need a drinking-bowl of special shape!'
Descriptive: ''Tis a rock!. . .a peak!. . .a cape! --
A cape, forsooth! 'Tis a peninsular!'
Curious: 'How serves that oblong capsular?
For scissor-sheath? Or pot to hold your ink?'
Gracious: 'You love the little birds, I think?
I see you've managed with a fond research
To find their tiny claws a roomy perch!'
Truculent: 'When you smoke your pipe. . .suppose
That the tobacco-smoke spouts from your nose--
Do not the neighbors, as the fumes rise higher,
Cry terror-struck: "The chimney is afire"?'
Considerate: 'Take care,. . .your head bowed low
By such a weight. . .lest head o'er heels you go!'
Tender: 'Pray get a small umbrella made,
Lest its bright color in the sun should fade!'
Pedantic: 'That beast Aristophanes Names Hippocamelelephantoles
Must have possessed just such a solid lump
Of flesh and bone, beneath his forehead's bump!'
Cavalier: 'The last fashion, friend, that hook?
To hang your hat on? 'Tis a useful crook!'
...Continues...
Emphatic: 'No wind, O majestic nose,
Can give THEE cold!--save when the mistral blows!'
Dramatic: 'When it bleeds, what a Red Sea!'
Admiring: 'Sign for a perfumery!'
Lyric: 'Is this a conch?. . .a Triton you?'
Simple: 'When is the monument on view?'
Rustic: 'That thing a nose? Marry-come-up!
'Tis a dwarf pumpkin, or a prize turnip!'
Military: 'Point against cavalry!'
Practical: 'Put it in a lottery!
Assuredly 'twould be the biggest prize!'
Or. . .parodying Pyramus' sighs. . .
'Behold the nose that mars the harmony
Of its master's phiz! blushing its treachery!'
--Such, my dear sir, is what you might have said,
Had you of wit or letters the least jot:
CYRANO
Sitting on an iron platform--thence
To throw a magnet in the air. This is
A method well conceived--the magnet flown,
Infallibly the iron will pursue:
Then quick! relaunch your magnet, and you thus
Can mount and mount unmeasured distances!
bump
it doesn't work and you're a retarded mongoloid nigger.