Quote from: leomillert on 07/14/2015 09:52 pmI'll try to write a step-by-step guide soon so others can do what I am doing in order to provide more data to the scientists.@leomillert (and @aero, @dumbo, et al.) - I started this page: http://emdrive.wiki/MEEP - please document your setup steps there, so folks can set up a new environment, compile MEEP, execute the .ctl file, and postprocess the CSVs as needed. And it would be great to put your .ctl file up on, say, Github and link to it as well. Perhaps @dumbo could also share his Amazon AMI with MEEP set up? I suspect there are a lot of lurkers out there who would like to lend a hand in these areas.
I'll try to write a step-by-step guide soon so others can do what I am doing in order to provide more data to the scientists.
What version of MEEP?
Windows or just Linux versions? Separate pointers to each setup section, as they're different.
What versions of which RPM/tar.gz/whatever packages for each dependency
Installation sequence
Then - how much process memory / system memory required?
Is it thread safe and if so, how many threads can be allocated usefully (may be result of trial and error)
And of course, a section on parallel / cluster installs
Quote from: rfmwguy on 07/14/2015 06:07 pmBuilding and thinking...of the 4 known fundamental forces, only gravity is assymetrical, meaning it is only attractive and cannot be repulsive. We have a problem here...CoE. with no cosmic balance, no conservation, the universe collapses...rapidly...yet it expands. This is a known fact.If, after the time of inflation, everything shrinks faster and faster inclusive all forces, but condensed matter(higher energy density, shrinks faster) and free space(lower energy density, shrinks slower) with different velocities, for any internal observer it seems to be a faster and faster expansion. Would be explain redshift for example Everything is relative...
Building and thinking...of the 4 known fundamental forces, only gravity is assymetrical, meaning it is only attractive and cannot be repulsive. We have a problem here...CoE. with no cosmic balance, no conservation, the universe collapses...rapidly...yet it expands. This is a known fact.
Quote from: deltaMass on 07/14/2015 10:03 am@WarptechA couple more notes:1. You say that you will address the incorrect assumption that the input energy term Pin*t is much smaller than the rest energy term m0*c2. Problem is that you never mention it again!!Furthermore, you apparently ignore the post I made showing that for eminently reasonable physical values, the input energy term is about 14 orders down on the rest energy term!! Why have you conveniently blocked this out? You are quite capable of calculating it yourself. Are you therefore prepared to admit that the input energy term can be neglected in comparison with the rest energy term?That being the case, all your equations collapse into tautology. ...@Warptech. At least do us the favour of replying to the first point here. You have done a lot of replying, but have studiously skirted this core point, it seems to me.The fact that your equations produce nonsense when you make this approximation is really your problem, not anyone else's. They are, after all, yours.Re. your query "How is 'k' measured?"At these severely sub-relativistic speeds (even the smallest experimental k-value predicts breakeven at less than 1%c) we don't need SR or GR. Pin is measured with a power meter onboard. Acceleration may be measured onboard with an accelerometer, or by an external inertial observer who logs deltaV over deltaT. There is no black magic to be squeezed from this. It is thoroughly mundane. Force F is directly calculable from acceleration (F = m a) because m is invariant to first order (and with 14 orders down on your SR twiddle, arguably to even higher order). Thus we can calculate 'k'.I'm with @wallofwolfstreet here: plug in some numbers and amaze us with your theory.
@WarptechA couple more notes:1. You say that you will address the incorrect assumption that the input energy term Pin*t is much smaller than the rest energy term m0*c2. Problem is that you never mention it again!!Furthermore, you apparently ignore the post I made showing that for eminently reasonable physical values, the input energy term is about 14 orders down on the rest energy term!! Why have you conveniently blocked this out? You are quite capable of calculating it yourself. Are you therefore prepared to admit that the input energy term can be neglected in comparison with the rest energy term?That being the case, all your equations collapse into tautology. ...
Quote from: aero on 07/14/2015 09:43 pm..You have confused me. Did you transpose the matrix? My csv files have 245 rows and JA columns = 261 columns.I will trust that you intended "rows" instead of "columns," because the x dimension corresponding to length is smaller than the y,z dimension corresponding to diameter of the cavity.All the numbers I gave you were correct. You are right, the words "row" and "column" in my post were transposed because I keep thinking of the EM Drive as being longer than its mean diameter, and I keep forgetting that your Finite Difference grid has more nodes in the diameter direction than in the longitudinal direction. If given the choice I would have put more grid points in the longitudinal direction, in the direction where the fields have the most variation. I am correcting the initial post to transpose rows with columns. Thank you. Also I keep thinking of the x axis as the horizontal axis, but your matrix is set-up so that x is in the vertical direction of the matrix (x indicates the number of rows) . My intuition is to have the z axis as the longitudinal axis of a cone, but you have the x axis as the longitudinal axis, so I have to keep reminding me of all this stuff (particularly when I type fast ). Too late to change it (these directions are arbitrary as long as we remember them). I would not be surprised if unwillingly I make the same mistake again (thinking of the x axis in the horizontal direction)
..You have confused me. Did you transpose the matrix? My csv files have 245 rows and JA columns = 261 columns.I will trust that you intended "rows" instead of "columns," because the x dimension corresponding to length is smaller than the y,z dimension corresponding to diameter of the cavity.
Quote from: deltaMass on 07/14/2015 07:23 pmQuote from: deltaMass on 07/14/2015 10:03 am@WarptechA couple more notes:1. You say that you will address the incorrect assumption that the input energy term Pin*t is much smaller than the rest energy term m0*c2. Problem is that you never mention it again!!Furthermore, you apparently ignore the post I made showing that for eminently reasonable physical values, the input energy term is about 14 orders down on the rest energy term!! Why have you conveniently blocked this out? You are quite capable of calculating it yourself. Are you therefore prepared to admit that the input energy term can be neglected in comparison with the rest energy term?That being the case, all your equations collapse into tautology. ...@Warptech. At least do us the favour of replying to the first point here. You have done a lot of replying, but have studiously skirted this core point, it seems to me.The fact that your equations produce nonsense when you make this approximation is really your problem, not anyone else's. They are, after all, yours.Re. your query "How is 'k' measured?"At these severely sub-relativistic speeds (even the smallest experimental k-value predicts breakeven at less than 1%c) we don't need SR or GR. Pin is measured with a power meter onboard. Acceleration may be measured onboard with an accelerometer, or by an external inertial observer who logs deltaV over deltaT. There is no black magic to be squeezed from this. It is thoroughly mundane. Force F is directly calculable from acceleration (F = m a) because m is invariant to first order (and with 14 orders down on your SR twiddle, arguably to even higher order). Thus we can calculate 'k'.I'm with @wallofwolfstreet here: plug in some numbers and amaze us with your theory.That's what I've been doing, messing with MathCAD on my (lunch?) break. Here you go. I will admit, @wallofwolfstreet was correct in that I need to include the kinetic energy in my Eout term, and what I have is not Eout but E-total. So progress is being made here... See attached PDF file with equations and plots from v=0 to c.Todd
Would anyone be interested that would model a perforated copper sheet for me in meep?I post the specs of the sheets and angles to run at.Shell
Are the heat effects within the -10° to 150° C range of a normal thermal camera? (Cost about £700)
Notice that this is the static thrust per photon in a rest (un-accelerated) frame traveling with the cavity. That is to say, thrust is dependent on the acceleration that the physical cavity experiences and goes to zero at the acceleration g. This is an example of a negative feedback system where the steady state acceleration in the cavity frame of a free cavity will always be less than that calculated from the static force. It has no dependence on the linear velocity. (The case of circular motion is different in that the centrifugal "force" is dependent on angular velocity and will further negatively affect the thrust.)
the number of cycles for the photons in the cavity to reach velocity c
@leomillertI think you're fine - looks like you have a good meep install.Yes, all of the numbers in your csv file were different than the numbers in my csv file, the not by much. I loaded both csv files into a spread sheep program then subtracted one from the other, entry by entry. Then I looked for the largest positive difference and the absolute value of the largest negative difference. I came up with 4.16333634234434E-017 and 2.7972416050126E-017. That is the difference in numerical precision of our two machines, nothing more.You're good to go, and for all you theorists out there, leomillert is now set to generate meep data for you.and leomillert, here are some links to manuals that you may wish to bookmark if you haven't already.http://www.gnu.org/software/mit-scheme/documentation/mit-scheme-user.pdfhttp://www.gnu.org/software/mit-scheme/documentation/mit-scheme-ref.pdfhttps://www.mail-archive.com/[email protected]/ - You may need to join.http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorialhttp://ab-initio.mit.edu/wiki/index.php/Meep_Referencehttp://ab-initio.mit.edu/h5utils/h5topng-man.htmlhttp://ab-initio.mit.edu/h5utils/h5totxt-man.htmlhttp://www.hdfgroup.org/products/java/hdfview/UsersGuide/index.htmland don't forget, Google is your friend.aero