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ITT: RF resonant cavity thrusters (aka EmDrive)
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ITT: RF resonant cavity thrusters (aka EmDrive)
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>>7766777
ITT: pseudoscience
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>>7766797
It's a pretty solid looking theory, and tests so far have been successful. Granted, everything is pseudoscience until proven, but it's been recreated by different people of all different backgrounds around the world.
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>>7766806
>It's a pretty solid looking theory,

No it absolutely is not solid looking. Whatever is going on with that thing, it's definitely not what that image says.
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>>7766818
I've made my point, your evidence for its non-existence is?
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>>7766806
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Have there been any experiments done to actually prove the validity of the "microwaves bouncing off the sides of a truncated cone produces net force" principle?
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>>7766842
Several. And if it isn't the proposed theory, then there's another way to make thrust without propellant. NASA's test showed it produced about 50 micronewtons. With a decent cooling system, it can only get better.
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>>7766859
Post links to the journal articles describing those experiments.
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>>7766862
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140006052.pdf
That's NASA's report.
Not much to find due to how shunned the theory is.
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>>7766777
This image makes me fell like fucking around randomly with science stuff in your garage yields better results than going to a university
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>>7766895

Except it's important to note that this image isn't true. It's water memory tier science.

>>7766806
>solid looking theory
>Theory is completely contrary to all known laws of physics
>solid looking.
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Using K as the thrust per watt of this device.

Recalling that Power = Force * Speed.

Using P_in for power in Force F is:
F = P_in * K

Plugging in to the above for power out P_out and using V as velocity:
P_out = P_in * K * V
For V > 1/K , P_out > P_in

therefore it's an overunity device. Unless efficiency decreases with speed like with real rockets
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>>7766916
It doesn't contradict any laws of physics. Known or unknown.
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>>7766818
>>7766841
Reminder that experimental results trump theoretical assumptions. If indeed it is proven to work that is.
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>>7766964
See
>>7766952
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>>7766916
There WAS debate over whether it broke Newton's second law, the law of conservation of momentum, but it doesn't. The momentum exchanges between the EM wave and the engine itself. Only two reasons this theory isn't taken seriously. One is that it takes time to understand, and even then it's difficult to grasp, and two, the theory's creator has such extravagant plans. The man is undoubtedly a genius though. Perhaps he will get his recognition after his death.
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>>7766981
So the EM wave is accelerated out the back like rocket fuel?
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>>7766982
That's the resonant part. It bounces around inside, radiation pressure.
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>>7766964
And why does violating conservation of energy not contradict any laws of physics?

>>7766985
so what about the force on the walls of the tapered cavity not just the ends? I think you are forgetting something here....
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>>7766993
I'm samefag, soooo
1. No other laws of physics have been brought up in my knowledge, so it's either I don't know enough about the subject, or no arguments have been made for other laws being broken.
And, it doesn't break conservation of energy.
2. Pushes outwards, or back a little bit. Positive readings were still obtained.

Yes, this isn't a wonder magic engine, but for long flight craft, like probes, it could be very, very good. Entirely solar powered engines that only get faster, because unless they break, which is unlikely due to the lack of moving parts, it can just keep accelerating. That's where it gets, iffy. In theory, it could surpass C, but that's why development is needed. It obviously won't, but the number 60% light speed keeps getting thrown around (might be media hype though, not sure)
Anyways, it's just another form of clean energy to be looked at. Isn't this the first electronic engine to work in a vacuum? That's a feat on its own.
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>>7767013
>Isn't this the first electronic engine to work in a vacuum?
This statement alone makes it obvious you have no idea wtf you're talking about
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>>7767018
Uh what about the thing going over c because it has constant acceleration? kek I think he's pretending to be retarded.
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>>7767030
zozzle
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>>7767018
OP here, I was busting. I like the idea of this, and hope it works out, but looking at ion engines, meh.
muh stupids
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This reminds me of something I dealt with in Telecommunications which is called a waveguide. Anyway this was only certificate level education so we were taught that a waveguide is essentially a lossless method of transmitting microwaves if calibrated to the correct frequency.

Am I talking /completely/ out of my ass here?

Also I remember reading about something similar in a New Scientist magazine around ten years ago, and published in this article was that men in suits had come along and tried to do the hush hush because it was bad for the economy. But... Media huh.
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>>7767135
Waveguides are everywhere. Look in your microwave oven and take off that cardboard bit on the right side, thats a waveguide.

They aren't lossless, but they are very efficient because the width is a factor of the frequency.
You can also rotate the polarization by twisting the guide.
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>>7766777
Why, exactly, does everyone say this violates thermodynamics? This picture is actually the first time I've seen an explanation of how it works, and I don't see anything that immediately appears absolutely outrageous.
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>>7767304
It's blatantly obvious why it doesn't work if you know even highschool physics.

here is one explanation:
>>7766952

the only people shilling this are idiots that don't know shit about physics
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>>7767307
That doesn't prove anything, especially because there's a caveat right at the end of the post which is very likely true. K (thrust per watt) likely depends on the rocket's speed.

The way I'm looking at it, photons are being ejected preferentially in one direction away from the device and the reaction force propels it the opposite direction. Where are the violations? It's literally the same thing as ion drive except with photons instead of ions.
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>>7767322
because that would generate as much force as a flashlight you idiot
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>>7767323
A flashlight does not emit 700 watts of light, dipshit. We're talking in terms of millinewtons, too. I haven't done the math but it does not sound completely unreasonable. I'm not even claiming it's true; all I'm saying is that it doesn't "violate the most basic laws of physics" like every pop-sci article title I've come across proclaims.
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>>7766777
Someone feel free to shit on this post hard, but I was wondering if this "theoretically possible" because one side is being more exerted by an energy source than the other side, and since matter and energy are linked, is it not using energy as it's propellant?

>I honestly have no fucking clue on the math or even the fucking theory behind this thing
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>>7767332
So why wouldn't a 700 watt lamp do the same thing?
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>>7767361
producing 700 watts of visible light with light bulbs produces way more than 700 watts of heat. In theory, it would do the same thing though. I'm sure if you had sensitive enough test equipment, you could detect a force on a uni-directional antenna emitting RF radiation.
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>>7767322
>likely depends on the rocket's speed
Relative to what though?
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>>7767395
from a "stationary" perspective, as the rocket approaches the speed of light, the emitted radiation is being red shifted, ie. lower energy, lower thrust. The rocket can't break the speed of light because thrust decreases as velocity increases. From the rocket's perspective the thrust remains constant, however.
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>>7767432
>stationary perspective
AHAHAHAHAHAHAHAHAHAHA
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> put tons of energy input
> get an output so ridiculously small that you can't even distinguish from the margin of error
It's pesudoscience alright.
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>>7767013
>In theory, it could surpass C, but that's why development is needed
Not in theory, it couldn't. You'd need to do some serious messing with space-time to even THEORETICALLY surpass C. It's impossible to actually reach C through acceleration, you can just get arbitrarily close. However, it would permit near lightspeed travel (like 0.999c or so) which is otherwise impossible without massive fuel tanks, even with photon rockets powered by a magical infinite power source.
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>>7767322
If it ejects photons, there's nothing extraordinary about the EM drive, it's just a photon rocket, which we've known about for years. And they're still bound by the rocket equation, even if they do have an absurdly high specific impulse. Whereas a reactionless drive which the EM drive supposedly is, would complete eliminate the need to carry propellant.
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>>7766842
No, nobody has proven that's what is happening.
When the test was done properly in a vacuum, the thrust dropped to near zero. So near to zero that the effect could be something like copper atoms being ejected.
It seems like it was essentially working as a heater/fan in the first test.
>>7766859
>then there's another way to make thrust without propellant
Noooo...
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>>7767322
>photons are being ejected
So it isn't propellant-less.
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>>7767456
AHAHHAHHAHAHA
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What makes light go fast?
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>>7768477
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>>7767432
That has nothing to do with the point that the rocket's kinetic energy becomes greater than its energy input. Calculate it using the relativistic velocity and you will get the same result. A propulsionless drive can't have a thrust to power ratio greater than a photon rocket without breaking conservation of energy.
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This is all perfectly explicable if you believe Woodward's work on Mach's Principle.
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>ditch e=mc^2 altogether
>fucking turn light into matter somehow
>exert a force on something that isn't even a geometric square
someone explain it do we literally think there's a complex number system for imaginary fields now or what
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>>7766777

>RF resonant cavity thrusters (aka mEmE Drive)
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>>7766806
>Granted, everything is pseudoscience until proven
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I don't understand how dismissive the mainstream is of this experiment, which deserves at least some earnest debate without being shouted down by naysayers. Photon energy is known to have some momentum effects in some situations, and devices like the photometer show this undeniably.

https://en.wikipedia.org/wiki/Radiation_pressure
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>>7768096

You are a liar.
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>>7766818
https://en.wikipedia.org/wiki/Ion_thruster

It's as wacky and out there as the Ion thruster Nasa used
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>>7770845
> photons with no mass is turning a metal plate
its probably the heated air rising thats rotating the thing.
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>I don't understand how the observed effect is possible
>therefore it's impossible QED

Sure is science lately.
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>>7770928
This is it, otherwise the plates could be any other colour. The black faces are heated more than the white faces, generating wind resistance.
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>>7770928

Radiometers are a vane in a vacuum. Also consider solar sails. Radiation transfers momentum, this is a proven fact.
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>>7770920
I don't know who you think you're fooling but a true reactionless thruster would be far more wacky than anything that shoots out particles to move.
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>>7770939
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>>7770845

1) Photon momentum is not in dispute. Photon rockets are a 100 year old idea.
2) The meme drive is not supposed to be a photon rocket.
3) That radiometer does NOT work by photon pressure. Look it up if you don't believe me.
4) Sonce you thought that was "undeniable" but it turned out you were wrong, maybe you should recalibrate your standards for undeniable.
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>>7770845
>>7770931
Crooks radiometer is not an example of radiation pressure. Anyone who has actually seen one can tell you the sails are pushed away from the black side, not the silvered side despite it having twice the radiation pressure. Pic related.

The actual reason it works is because of residual gases, vacuums are not total voids.

Radiation pressure is a proven fact but this is an example of why you should be careful voyaging into a topic you are ignorant about. Also a good example that experiments are not immune to systematic effects. EMdrive isn't a photon rocket, it isn't expelling photons for momentum. That wouldn't generate the claimed trust and it is now how the inventor claimed it worked (despite teh fact he is wrong).
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>>7770980
>>7770983

Here we go, delving into semantics.

I feel bad for you, I really do.
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>>7771062
It's not semantics. Not only is your point wrong, its also irrelevant towards the meme drive, which has an alleged thrust to power ratio higher than a photon rocket and is not claimed to be a photon rocket.
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>>7771134

Who's claiming that it's a photon rocket? But the main argument against the drive is that it's impossible to have a reactionless drive implying that without matter, there is no momentum.
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>>7771200
>Who's claiming that it's a photon rocket?
>>7767322
>>7770845

>But the main argument against the drive is that it's impossible to have a reactionless drive implying that without matter, there is no momentum.
No it's not. Anyone who knows anything about aeronautics knows about photon rockets. anyone who knows basic physics knows that photons have momentum without mass. The main argument against the meme drive is that it violates conservation of energy and has no coherent explanation for how it works.
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>>7771244
>has no coherent explanation for how it works

Therefore it doesn't work, right? Observation trumps theory.
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>>7771313
Observations so far have failed to show that it *works*. What they do show that there's a tiny amount of thrust coming from an effect that could easily turn out to be totally unsuitable for the application because it's a result of electromagnetic interaction with something down here on Earth. If somebody enterprising thinks there's a novel effect here they should go and get rich with it, by all means.
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>>7771326

Multiple independent experiments have failed to dispsel the observation either. Meanwhile armchair commentators poopoo it purely on the basis that they cannot understand what could be happening therefore it's impossible.
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Why don't they just hook it up to an E-Cat and fly to Mars?
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>>7766777
Thread replies: 71
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