Scientists of 4chins... I have currently accessible funds... the tentative game plan is as follows:
1) Buy a bunch of microwave ovens. 2) Rip out magnetrons. 3) Use the microwave oven cavities and wave guides to build a multisource emdrive that is light weight. 4) See if I can measure some thrust out of it.
Questions for you all:
1) Any thoughts/comments on the shape of the cavity? (I have a few ideas but want to crowd source) 2) I have access to vacuum chambers so I can test there too... any other considerations to have? 3) Any comments on the overall shape of the device based off experience/intuition. 4) Any comments on the overall theory/principles behind the design.
Tripfaggin it with a phd for longevity... will post proof of progress as it comes...
>1) Any thoughts/comments on the shape of the cavity I thought there were publications/patents filed by the guy that initially came up with it? Why not use his cavity? If you design your own and it doesnt work, we won't know if it is because you're retarded or because the drive doesn't work. Also using a simpler cavity should help in improving it later on.
Jonathan Ward
according to shawyer, the thrust depends on the conical shape...
The question is, which type of conical cavity?? which angle??? what area of base??? what about parabolic walled chambers? what about hyperbolic walled chambers? what ratio of cross sectional areas between the walls???
in short, what boundary conditions??? any insight?
Mason Barnes
bump
Jace Torres
Other than the fact that it wont work, go ahead and waste money, I mean solar sails would work a shit ton better (basically EM drives would violate the laws of physics, mainly conservation of momentum)
Landon Johnson
bruh... its not about "it wont work"... I AM going to engage in a very detailed scientific study of this thing...
post detailed scientific critiques... plox...
Parker Thomas
Yea, sry, my knowledge of this thing is solely from Veeky Forums, so can't help you on the physics/design. If you have some info on where to get started, post it and ill see if i understand something. Didn't nasa also want to investigate this? Someone must have some results already which you could build upon.
So the guy that claimed it works never specified what shape the drive needs? That seems sketchy and not very trustable desu.
Andrew Peterson
i suppose the initial intuition would be based on the standing wave produced by the specific geometry of the cavity and boundary conditions...
If anybody is an expert this would make good conversation...
Do you even have equipment to measure forces this small? 100s of mN/kW sounds ridiculous. I'm not sure I understand your question about the cavity. I'm an optics person so I know a little bit but not much about cavities.
Robert Wilson
As this is a general thread, here a general question: Why have Eagleworks only taken 6 measurements, each with only having the power on for about 40 seconds? Why not 100 or 1000 measures and also measures where they power it for 3 minutes or so? I mean they have this apparatus right there, it was probably expensive and took some time to manufacture, and then they just generate a handful of data points with it?
Nicholas Sullivan
Why not 100 or 1000 measurements*
Mason Nelson
good...
I have the equipment...
but lets talk optics... what are your immediate thoughts on the em drive? Can you envision a regime where an exotic thrust is possible?
What do you know about self accelerating beams?
What do you know about radiation pressure?
let us start a discussion...
Lucas Long
The idea is that their data looks like thermal cooling... i.e. the thrust they measured was basically heating up the metal...
I claim no right or wrong... just that I am, with explicit funding, pursuing a project that can be labeled an "emdrive".
Hudson Bell
>Any thoughts/comments on the shape of the cavity? (I have a few ideas but want to crowd source) Other than what was already said about the waste of money, since the memedrive doesn't work according to current physics, there is no equation that relates the thrust to the area difference or shape in any way, so we can't optimize it at all, no finite element method or euler lagrange equation for you.
Jace Perez
Ok, but do you know why they only published so few measurements? From those few data points you can just see that there is a huge volatility in thrust (or what appears to be thrust). The natural thing would be to take way more than 3 measurements per power and direction (I was wrong about the 6 measurements, they actually published 18 measurements, which is still a very low number), so you could determine the mean and the variance of thrust and of thrust-to-power with acceptably narrow confidence intervals.
Jace Adams
E.g. for 60W the mean thrust is believed to be between 35 and 141 µN with 95% probability, that's a really big uncertainty. From this data, there is also no significant difference of the thrust means of any of the 3 power levels. So you can't say shit with significance because there is too little data. 10 instead of 3 measurements per power output and direction would already allow for more statistics.
William Myers
>but lets talk optics... what are your immediate thoughts on the em drive? Can you envision a regime where an exotic thrust is possible? No, not really, from the little I read on their website it should have to do with SRT, I'll try to read the paper they published on the website and see if things make sense. >What do you know about self accelerating beams? Nothing, I know self-focussing (the nonlinear effect) and I know that people have realized "slow" light, even to the point that it completely stops in a mazerial. This may be related. >What do you know about radiation pressure? I know it exists and probably calculate simple problems related to it, I also know that there's a factor 2 for reflection ;) >let us start a discussion... Sry, really not well-versed on this topic.
Jaxon Gonzalez
Ok, started reading their background paper. I'm not sure I believe them on this part (P4)
>We note that if the forces had been the mechanical result of a working fluid within the closed waveguide assembly, then the resultant force would merely introduce a mechanical strain in the waveguide walls. This would be the result of a closed system of waveguide and working fluid. In the present system the working fluid is replaced by an electromagneticwave propagating close to the speed of light and Newtonian mechanics must be replaced with the special theory of relativity.
What does SRT have to do with the fact that he can gain thrust out of the system now, i.e. why does it become an open system? As long as this question is not clearly answered, I doubt it will work. The followup explanation merely rewrites the thrust formula in the relativistic form but fails to solve the more important issue of why does the system become open in relativity.
Joseph Butler
Ah, forgot the > on the second line, whatever, you get the point.
Also just realized that he doesn't consider red/blueshift in his formula for calculating the maximum reachable speed, while indifferent for the question at hand of whether it will produce thrust at all it isn't good practice to not even mention that that might affect performance. My guess is that it will make the "top speed" lower, since the waves hitting the front (accelerating?) plate will be redshift making their energy appear lower than it would be without the shift, for the backplate would be reverse.
Angel Edwards
They should just throw one on the Falcon Heavy test flight.
Matthew Wood
Bumping before sleep just to make sure OP will see it.
Evan Hill
Well, we'll see if you get the first microwave oven in orbit, I guess.
Chase Bennett
>>I know self-focussing (the nonlinear effect)
speaking of this... I had an idea related to self-accelerating beams that I think may be applicable... Although the poynting vector stays straight, there is a small force due to the beam curvature...
because even if this is possible we will never make it work.
you know why? because people are fucking stupid.
we will last another 500-1000 years.
at best, at the current rate of things
Jackson Price
my mommas
Colton Myers
Skimmed through that paper and at this point I think the particles that are considered are traveling with the wave. Is that correct? Also, from what I understand the beam is not self-accelerating but only accelerates a particle traveling in its wake?
My conclusion of that paper is that you can make a particle spiral with a lightbeam, but I don't see how that is useful for the engine, since it will at most make your engine rotate.
The self-focussing I know about is done in matter though, it may be applicable to what he is talking about in terms of a dielectric in the theory paper, since I assume you will have very high field strength inside your cavity. On the other hand, I think that the electric diple moment is generally small and does not show resonances in the microwave region for most materials so any NL effect may be negligible.
Ethan Sullivan
The idea I had was as follows...
1) The em drive chamber has a conical shape . 2) Standing waves, at least in quantum, in linear potientials (i.e. cones) produce airy functions. 3) Airy functions self-accelerate. 4) The paper I linked showed that, although small, there is a force perpendicular to the beam momentum along the direction of the acceleration. Hence the colloidal particles move along the beam arch. 5) Now, with the em drive, the idea I had was that the standing wave produced by the microwaves can be decomposed into a linear combination of airy functions (which self accelerate) and that is where the thrust comes from.
>>the beam is not self-accelerating but only accelerates a particle traveling in its wake?
A gaussian beam passes through a grating which produces destructive interference everywhere except along a parabolic arc; the resultant beam then "looks" bent. In the paraxial approximation of the helmholtz equation there is a mathematical duality between helmholtz and the schrodinger equation except the direction along the beam "z" in helmholtz is time in the schrodinger picture. So, one can look at the arc as moving through time along z... radiation pressure can then move colloidal particles along the arch...
sorry if I didnt explain things clearly...
pic related is an airy beam i made... I have a movie, i will see if i can upload it too...
Julian Gomez
Here is an actual dirty beam coming into focus and self-accelerating... remember time here is z along the beam, i am just pulling the camera back along a track...
>4) The paper I linked showed that, although small, there is a force /perpendicular/ to the beam momentum along the direction of the acceleration. Hence the colloidal particles move along the beam arch. How do I relate this to >In the paraxial approximation of the helmholtz equation there is a mathematical duality between helmholtz and the schrodinger equation except the direction along the beam "z" in helmholtz is time in the schrodinger picture. So, one can look at the arc as moving through time along z... radiation pressure can then move colloidal particles along the arch... this? I still can't follow on how you will be able to get a movement along the beam propagation direction, or are you suggesting that the engine is not moving along the direction of the cavity (up/down in the paper) but perpendicular to it?
>5) Now, with the em drive, the idea I had was that the standing wave produced by the microwaves can be decomposed into a linear combination of airy functions (which self accelerate) and that is where the thrust comes from. This should be possible for any wave, since Airy functions form a basis set, so it must have to do with how you add them together, which is probably a good starting point for computer-based modeling.
Could you still try to explain a little what is meant with self-accelerate? I can't wrap my head around a light-beam accelerating, sry.
Gabriel Rivera
>a larger version of the focusing beam... Hol'up, so you're focussing the beam? Then it's kinda obvious why it's traveling, you just didn't align the lens right making the focus travel as you go further down the beampath.
Nicholas Lopez
>How do I relate this to...
the duality merely relates motion along z to a time coordinate in the schrodinger picture... It just justifies how we can think of the z coordinate as "time". The beam travels along z, but with a perpendicular component, e.g. x or y... there is a force along z (just normal radiation pressure) but there is also a force perpendicular (x or y which is the direction the beam is bending in)...
>>I still can't follow on how you will be able to get a movement along the beam propagation direction
the acceleration is transverse (x or y) to the original beam direction (z)...
>>what is meant with self-accelerate? I can't wrap my head around a light-beam accelerating, sry.
think of it like light bending around a star in general relativity... the acceleration is transverse to the original beam direction. This is accomplished in the lab by diffraction. Using a specific grating, you can produce constructive interference along a parabolic path (the laser beam is literally bent).
Daniel Parker
>>Hol'up, so you're focussing the beam? Then it's kinda obvious why it's traveling, you just didn't align the lens right making the focus travel as you go further down the beampath.
good question... the beam, after passing through the grating needs to be in the far field... we do this with a lense... the lens has a focal point which is smeared out spatially along z. Depending on the optics and laser frequency the beam length, along z, where things are in focus changes... we want this to be as long as possible... my set up had it around 40 cm... To Next, to make sure the beam was aligned, i.e. the movement you see in the video wasnt from a misaligned beam, we used a bessel beam (which doesnt accelerate) and make sure it stays stationary as we pull the camera back...
Tyler Howard
sorry, these posts were mine... forgot my tripfaggotry...
Oliver Lee
It needs to be superconducting according to the people behind the meme drive. The memedrive doesn't work and if it did, it would be a perpetual motion machine
Isaac James
ok, so with Bessel beams it will be only changing size, right?
thanks for clearing up things.
and I accidentally left mine on
it doesn't need to be, it will only give you better thrust/power which is almost obvious
Tyler White
here is the bessel beam which shows the alignment... it drifts down a bit but whatever...
Having the walls be superconductors would make the drive more efficient by basically giving a stronger boundary condition at the surface... no penetration etc...
Henry Parker
yea, definitely different to So, do you have any idea on how to measure thrust solely from the Airy beam? I think that may be a good preliminary experiment, take the sperical particles from the PRA paper for example and see if it will accelerate.
Juan Moore
>>to measure thrust solely from the Airy beam? I can think of multiple experiments but I figured since cost of an em drive is so cheap... basically the cost of a couple microwaves that it would be advantageous to just build it and see if it works...
The game plan is to buy something like 5 microwaves and use the actual interior of the microwave itself as the housing (just hammer everything flat and then weld everything together)... then attach a wave guide and dump all five magnetrons into it... but I am going to keep the actual device as light as possible and have the magnetrons off on the side... basically the lightest cavity with the most power...
This might resolve the seeming overunity issues with these proposed thrusters by making a case that the system is actually open, just in a way that's hard to detect.
Ayden Evans
>I can think of multiple experiments but I figured since cost of an em drive is so cheap... basically the cost of a couple microwaves that it would be advantageous to just build it and see if it works... Wasn't thinking about the price, but more concerned about you messing up your cavity and not getting perfect airy beams ruining the possible thrust. If you could prove that the airy beams will accelerate a particle, at least we know that part works and it's only up to the correct cavity design. Especially since the paper never mentioned anything about the type of beam you need to make this thing work, I'm not sure your approach would work or maybe even improve the whole system, since designing your beam would most likely give you more thrust than just dumping energy into the cavity.
Lincoln Lewis
>I AM going to engage in a very detailed scientific study of this thing
Right, then. What sort of instrumentation are you going to use to measure any thrust that might be produced?
Wyatt Gomez
Why? There are literally billion better ways to use that payload capacity.
Ian Evans
Interesting... I scanned through the video... i will look more into it and the mach effect as well...
Asher Cruz
This is true... my ultimate goals is to literally build a long ass triangular wave guide (like a toblerone), put a microwave grating and lense in it to make a microwave airy beam, and let it push up on the roof (while the poynting vector stays straight)... and crank up the power... doneskis... going to the mars... :)
Gavin Richardson
a digital drug dealers scale... but we got access to vacuum chambers specifically designed to test satellites for space readiness... this will ensure we are not dealing with thermal effects...
Matthew Kelly
stick on a thermometer and run it until you reach equilibrium or it melts to exclude thermal effects for sure. Not those pissy 100s like these guys did
Colton Richardson
>inb4 its simple ablation >with exhaust velocity of c
Jeremiah Smith
Because odds are it's going to explode so they aren't doing anything with the payload. May as well toss a microwave on board and see what happens.
Nathan Taylor
I've been following the threads on the meme drive occasionally at the cancerous dystopian moderation tier nasaspacefaggots.com forum which coincidentally like all forums is pure cancerous dystop... whatever. There really hasn't been much development aside concentrated autism and tinfoil as well as several disappointments especially related to the chink tests which turned out false. If you actually have vacuum chamber and the time/money to spend on testing, and the damn thing turns out working, I'll suck your dick nonstop all along the way to alpha centaury and back. No homo btw.
Justin Harris
Stream its maiden run so we can see you fuck up and get fried live
Bentley Gomez
lol... sabed...
Jayden Bennett
if it actually works well I will definitely dump vids...
Jayden King
Whatever happens user, don't give up, I think I you have a part to play in all this.
Andrew Carter
dump vids of it not working as well, we need results, positive or negative.
