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#2720 by dustinthewind on 09 Feb, 2016 04:21
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Assuming your idea is correct. You still missing a key part of the proposal woodward is making in his Mach Effect Thruster proposal.Sure One part is the ability to change the mass of part of the thruster in a controllable manner. But the other part is to generate a force on the fluctuating mass. From Woodwards perspective it is a 4 step process.
Lets assume that the part of the thruster that can have its mass changed controllably is called FM
1. Increase the mass of FM (FM is now FMlarger)
2. Generate a force that pushes against FMlarger
3. Reduce the mass of FM (FM is now FMlighter)
4. Generate a force that pulls on FMlighter
I think the changing of the mass is when the photon enters or exits the dielectric. (If the mass of the light does change. pretty sure its velocity changes.).
The exerting a force on the object that changed mass is the curved path that the photon has to take.
I'm now wondering how this curved path is different from a single reflection. i.e. the EM drive with a dielectric.
My first thought is to examine the ratio of energy exchanged on one reflection between the photon and cavity (propulsion efficiency). Then examine the ratio of energy exchanged by reflection in the dielectric and see if they are different.
@UberOverLord - I think copper is preferred because of the low resistance to increase Q which is related to the ability of the cavity to reflect light. The less resistance the material has to current, the less energy upon reflection is converted to heat. A silver coating is a bit better than copper and polishing the surface I think helps. Superconductors reflect the best, due to their low resistance. Some materials don't reflect certain types of light, such as glass reflecting visible light, but glass does have an index of refraction and slows down visible light.
I am speculating the photon may change mass in a dielectric, which has an index of refraction, which I am not certain of but may explain the change in velocity. The paper I cited http://physics.weber.edu/galli/EffectivePhotonV2-1.PDF may suggest light doesn't change in mass and that some how momentum is exchanged with the dielectric upon exit and entry (while still slowing down the light), unless I am mistaken in my understanding of it. -
#2721 by TheUberOverLord on 09 Feb, 2016 05:39
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I have an odd question. Maybe Dr. Rodal and/or others can help.
While I understand that a photon has no rest mass.
Is there a maximum mass when a photon is moving at or near the speed of light and does it vary by what element the photon was created from?
Example: Is there some sort of advantage of photons being created by copper atoms in a EM Drive caused by RF frequency excitement, over other metals or even other elements? As far as having a greater mass when traveling at or near light speed than say atoms being excited in a aluminum EM Drive cavity producing photons. When they are moving at or near light speed?
If there is? Are there any atoms that would have substantial benefits over copper atoms as far as the mass of photons traveling at or near light speed, created based on being excited in a EM Drive cavity by forces like RF frequencies?
Just wondering why copper seems to be a overwhelming, choice to use when creating EM Drives?
Example: If glass was used as a EM Drive cavity, would photons produced by the atoms of glass, excited by RF frequencies, have any lower or higher mass when they are traveling near or at the speed of light?
Note: I realize that all photons are born at the speed of light. So, I think.
Better said. While I know that all photons travel at the speed of light, is there any difference on the moving mass of the photon based on what element caused the photon to be created?
Once more DIY builds are done. I hope sometime in the future, that the EXACT same size/shape EM Drive cavities are compared say copper to aluminum. Just to see if somehow if the elements that comprise the EM Drive cavity have any influence with thrust measurements.
Right now it seems that shape and size of the EM Drive and RF frequency, is considered to be the only major influence to contributing to any thrust created. Worse case, would like to see end plates ("One at a time and then both") replaced with another metal, or other element as well. If it's too complicated at this stage for a DIY builder of a EM Drive to EXACTLY reproduce, in say copper and then aluminum or some other element. The same EM Drive, within tight tolerances.
Don -
#2722 by rfmwguy on 09 Feb, 2016 12:24
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I only know of one person right now at jpl. They are at a low level and he publicly disregards anything to do with the emdrive (via a forum nickname). Based on that one perspective alone, I view them as wanting to play it safe with older, proven technology. Lip service is my guess but we can hope for the opposite.Tangent Alert - JPL's past present and future (on propulsion)
Recently, JPL has branched out by hiring climatologists as they continue to expand on their original purpose for NASA. However, a 2014 video does lay out some future plans regarding space propulsion. As you probably already know, they are 100% behind classic rocket propulsion, but the speaker does mention "something else" towards the end...
If you are wondering if they would be/are supportive of EMDrive research or testing, its probably best if you view the video...a total about 90 minutes. The first hour is simply a JPL history lesson. Future propellant considerations include green fuel and "something else".
Really like the mention on Nuclear Thermal. I only hope this isnt just lip service. We could colonize our solar system with a mixture of VASIMIR, Fusion Rockets, and Nuclear Thermal -
#2723 by rfmwguy on 09 Feb, 2016 12:52
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I have an odd question. Maybe Dr. Rodal and/or others can help.
rf injection into a copper vessel releases copper ions and free electrons from what I take is due to photon absorption. Copper is a heavy ion in comparison to free electrons and the photons themselves. Others have speculated on other particles created, axioms might have come up. Regardless, there's still a debate on momentum transfer of whichever particle or wave you might choose. Doc is one of the leading thinkers on this. His nsf topic for institutions is another place to go for more insights:
While I understand that a photon has no rest mass.
Is there a maximum mass when a photon is moving at or near the speed of light and does it vary by what element the photon was created from?
Example: Is there some sort of advantage of photons being created by copper atoms in a EM Drive caused by RF frequency excitement, over other metals or even other elements? As far as having a greater mass when traveling at or near light speed than say atoms being excited in a aluminum EM Drive cavity producing photons. When they are moving at or near light speed?
If there is? Are there any atoms that would have substantial benefits over copper atoms as far as the mass of photons traveling at or near light speed, created based on being excited in a EM Drive cavity by forces like RF frequencies?
Just wondering why copper seems to be a overwhelming, choice to use when creating EM Drives?
Example: If glass was used as a EM Drive cavity, would photons produced by the atoms of glass, excited by RF frequencies, have any lower or higher mass when they are traveling near or at the speed of light?
Note: I realize that all photons are born at the speed of light. So, I think.
Better said. While I know that all photons travel at the speed of light, is there any difference on the moving mass of the photon based on what element caused the photon to be created?
Once more DIY builds are done. I hope sometime in the future, that the EXACT same size/shape EM Drive cavities are compared say copper to aluminum. Just to see if somehow if the elements that comprise the EM Drive cavity have any influence with thrust measurements.
Right now it seems that shape and size of the EM Drive and RF frequency, is considered to be the only major influence to contributing to any thrust created. Worse case, would like to see end plates ("One at a time and then both") replaced with another metal, or other element as well. If it's too complicated at this stage for a DIY builder of a EM Drive to EXACTLY reproduce, in say copper and then aluminum or some other element. The same EM Drive, within tight tolerances.
Don
http://forum.nasaspaceflight.com/index.php?topic=39214.0
Most are keeping open minded on the possibilities...new ideas welcomed as always. -
#2724 by birchoff on 09 Feb, 2016 16:00
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I only know of one person right now at jpl. They are at a low level and he publicly disregards anything to do with the emdrive (via a forum nickname). Based on that one perspective alone, I view them as wanting to play it safe with older, proven technology. Lip service is my guess but we can hope for the opposite.Tangent Alert - JPL's past present and future (on propulsion)
Recently, JPL has branched out by hiring climatologists as they continue to expand on their original purpose for NASA. However, a 2014 video does lay out some future plans regarding space propulsion. As you probably already know, they are 100% behind classic rocket propulsion, but the speaker does mention "something else" towards the end...
If you are wondering if they would be/are supportive of EMDrive research or testing, its probably best if you view the video...a total about 90 minutes. The first hour is simply a JPL history lesson. Future propellant considerations include green fuel and "something else".
Really like the mention on Nuclear Thermal. I only hope this isnt just lip service. We could colonize our solar system with a mixture of VASIMIR, Fusion Rockets, and Nuclear Thermal
If when you say "older proven tech" you mean standard rocket equation based propulsion. Then I have no problems with that. Like I said I think it is perfectly possible for us to economically colonize the entire solar system with rocket based propulsion. But Chemical Rockets need to be retired or at the very least be limited to Earth to orbit scenarios and attitude control. Though I am not sure they are even needed for attitude control, since you could use gyros to accomplish the same thing.
We need strong investment in Space based nuclear power reactors. Which will enable Vasimr which is honestly a vast leap over current ion drive capabilities. With the additional bonus of providing power for long term manned deep space travel. In parallel, Nuclear Fission Thermal Rockets and longer term work on Nuclear Fusion Rockets. -
#2725 by rfmwguy on 09 Feb, 2016 18:18
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I agree, whatever gets us to orbit, we need something else rather than gravity assist and coasting.
State of nasa speech had something in it for everybody, as designed. Mainly a marketing pitch for politicians, it did have some big picture ideas. Mars is on inside nasa. Outside? Who knows...its election season. Good pep talk for employees...I've heard enough of them to say this one was pretty good. Now, for the few key words.
"Transform propulsion" I took to mean aerospace dollar savings for the airlines.
"Making science fiction science fact" open-ended, non-descript big idea.
"Citizen scientists" and "garage work" seemed to indicated their knowledge of private ventures into aerospace/space technologies.
Decent employee and investor speech. Charles Bolden's own personality came through. Likable enough guy imo.
Just my take on it...fwiw.
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#2726 by aero on 09 Feb, 2016 20:08
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@rfmwguy and all antenna people - Meep only provides dipole sources natively, so I'm trying to cobble together something that works like a monopole.
Does the antenna pattern in the attached cavity look like a monopole?
aero
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#2727 by Rodal on 09 Feb, 2016 20:36
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...
Dr Rodal, a technician in Melbourne suggested a solid inner frustum a few years back, are you thinking the same thing?
Attached are two older papers about waveguide tapers. Not sure of their relevance...
Q1: Dr Rodal, a technician in Melbourne suggested a solid inner frustum a few years back, are you thinking the same thing?
No, I am not suggesting that. Actually I don't understand the suggestion: what is the solid inner frustum made of? (is it a dielectric?), what are its dimensions and location, and what is the reason for the suggestion?
Q2: Attached are two older papers about waveguide tapers. Not sure of their relevance...
Thank you so much for those two references
which I had not previously seen.
The first one from the Bell Journal (1967) is excellent !
I think Dean's idea was to have a solid copper frustum and somehow make it resonate. An inside out, or rather an outside in, emdrive. Not sure if this would be feasible or useful or how it would work.
I don't know what he had in mind with a "solid copper frustum" resonating electromagnetically
But, thinking instead of a cavity formed from coaxial cylinders (and hence one in the form of coaxial truncated cones) one inside the other, a double-walled cavity:
1) in addition to TE and TM modes would also have TEM modes for which the axial field would be zero: Ez = Bz = 0
2) There would even be a zero-frequency mode (DC) mode having no electric field components, corresponding to an upward current on the outside cylinder and a downward current in the inside cylinder.
I don't immediately see why this would be of any help, but it is interesting
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#2728 by rfmwguy on 09 Feb, 2016 20:52
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@rfmwguy and all antenna people - Meep only provides dipole sources natively, so I'm trying to cobble together something that works like a monopole.
Does to me, the ground half of the monopole is the cavity itself.
Does the antenna pattern in the attached cavity look like a monopole?
aero -
#2729 by zen-in on 10 Feb, 2016 00:27
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I agree, whatever gets us to orbit, we need something else rather than gravity assist and coasting.
State of nasa speech had something in it for everybody, as designed. Mainly a marketing pitch for politicians, it did have some big picture ideas. Mars is on inside nasa. Outside? Who knows...its election season. Good pep talk for employees...I've heard enough of them to say this one was pretty good. Now, for the few key words.
"Transform propulsion" I took to mean aerospace dollar savings for the airlines.
"Making science fiction science fact" open-ended, non-descript big idea.
"Citizen scientists" and "garage work" seemed to indicated their knowledge of private ventures into aerospace/space technologies.
Decent employee and investor speech. Charles Bolden's own personality came through. Likable enough guy imo.
Just my take on it...fwiw.
When I started working at NASA over 20 years ago a mission to Mars was thought to be possible within 20 years. Are they still saying that? -
#2730 by Rodal on 10 Feb, 2016 00:37
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Sounds like fusion powerplants: the answer is that they are always 20 years into the future, ever since the 1960'sI agree, whatever gets us to orbit, we need something else rather than gravity assist and coasting.
State of nasa speech had something in it for everybody, as designed. Mainly a marketing pitch for politicians, it did have some big picture ideas. Mars is on inside nasa. Outside? Who knows...its election season. Good pep talk for employees...I've heard enough of them to say this one was pretty good. Now, for the few key words.
"Transform propulsion" I took to mean aerospace dollar savings for the airlines.
"Making science fiction science fact" open-ended, non-descript big idea.
"Citizen scientists" and "garage work" seemed to indicated their knowledge of private ventures into aerospace/space technologies.
Decent employee and investor speech. Charles Bolden's own personality came through. Likable enough guy imo.
Just my take on it...fwiw.
When I started working at NASA over 20 years ago a mission to Mars was thought to be possible within 20 years. Are they still saying that?
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#2731 by RotoSequence on 10 Feb, 2016 00:44
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Sounds like fusion powerplants: the answer is that they are always 20 years into the future, ever since the 1960's
There are few things that frustrate me quite like the split between funding something and actually funding something enough to accomplish their goals.
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#2732 by spupeng7 on 10 Feb, 2016 00:59
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Hope the weather is improving there in the US of A. End of winter soon so here is a little cheer up to help you through, one of three planets discovered about Wolf 1061 (December 2015) is potentially habitable
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#2733 by rfmwguy on 10 Feb, 2016 01:10
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You've got it zen, bolden said 2030s. A tried and true methodology for long term funding strategies in government. In my old corporate world...it was usually a 5 year plan...I agree, whatever gets us to orbit, we need something else rather than gravity assist and coasting.
State of nasa speech had something in it for everybody, as designed. Mainly a marketing pitch for politicians, it did have some big picture ideas. Mars is on inside nasa. Outside? Who knows...its election season. Good pep talk for employees...I've heard enough of them to say this one was pretty good. Now, for the few key words.
"Transform propulsion" I took to mean aerospace dollar savings for the airlines.
"Making science fiction science fact" open-ended, non-descript big idea.
"Citizen scientists" and "garage work" seemed to indicated their knowledge of private ventures into aerospace/space technologies.
Decent employee and investor speech. Charles Bolden's own personality came through. Likable enough guy imo.
Just my take on it...fwiw.
When I started working at NASA over 20 years ago a mission to Mars was thought to be possible within 20 years. Are they still saying that?
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#2734 by rfmwguy on 10 Feb, 2016 02:11
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No expert on nasa but seems to me they're trying to be all things to all people. They've adopted the name earth sciences leader over NOAA and aerospace leader over the FAA, USAF and private industry. I was left with the impression that it needs to be broken up into more functional entities, climate studies, aerospace engineering, manned and robotic space exploration. Too much under one umbrella imho. Separate budgeting and management for each. Cooperation when needed. It just seems too massive and complex to focus collectively on all things simultaneously. A private company would never want to put themselves in a position like this imo. Its called a spinoff...a new division perhaps a new company. I have a hunch bureacracy doesn't work this waySounds like fusion powerplants: the answer is that they are always 20 years into the future, ever since the 1960's
There are few things that frustrate me quite like the split between funding something and actually funding something enough to accomplish their goals.
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#2735 by 1 on 10 Feb, 2016 04:36
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This, at least from a 'normal, currently understood' standpoint, I can answer. Your questions themselves are a bit loaded however, when you say 'photon'. But first things first,
I have an odd question. Maybe Dr. Rodal and/or others can help.
While I understand that a photon has no rest mass.
Is there a maximum mass when a photon is moving at or near the speed of light and does it vary by what element the photon was created from?
Photons never have mass, only energy. Although the line between mass and energy becomes blurred in regimes where relativistic effects dominate (e.g. black holes), for 'normal' purposes photons always have zero mass. By consequence of the standard model, particles of zero mass must travel at lightspeed; and therefore:QuoteExample: Is there some sort of advantage of photons being created by copper atoms in a EM Drive caused by RF frequency excitement, over other metals or even other elements? As far as having a greater mass when traveling at or near light speed than say atoms being excited in a aluminum EM Drive cavity producing photons. When they are moving at or near light speed?
If there is? Are there any atoms that would have substantial benefits over copper atoms as far as the mass of photons traveling at or near light speed, created based on being excited in a EM Drive cavity by forces like RF frequencies?
Just wondering why copper seems to be a overwhelming, choice to use when creating EM Drives?
photons are elementally agnostic, which is to say a 5eV photon emitted from copper is indistinguishable from a 5eV photon emitted from aluminum, or anything else. Both travel AT lightspeed, and have the same energy; and if you do know a way to tell the two apart, then PM me because we're going to make a lot of money.
The thing is, your questions, as they pertain to EM drives, don't actually have anything to do with photons. You're asking about interactions between E&M fields at the boundary between empty space and bulk material, and that's a whole different beast. The word 'photon' implies a free-space, propagating solution to Maxwell's equations; and that's a very small subset of all possible solutions. Photons are a 'far field' construct, which is to say they're only well defined far away from the source that created them.
Quantum mechanically, this should be stated to be a 'real' photon, which has a real associated wavelength, real energy, and has a real/long lifetime. However, with an EM frustum, there really is no appreciable far field because your EM energy is confined to a space that's only a couple wavelengths long; if even that. Most interactions are therefore near-field, where 'normal' photons have no well-determined definition. Within the frustum, so-called virtual photons become important.
Virtual photons are also not well defined (nor well named, for that matter) but can be roughly thought of as a quantum field equivalent to evanescent/reactive/whatever solutions to traditional EM fields. They have a heavy presence near the 'source' of their generation, and rapidly lose importance the farther away from that source you go. All you need to know is that depending on the framework of your definition for virtual photons, they're allowed to interact with surrounding 'stuff' in ways that maxwells equations alone do not. Many such theoretical frameworks exist. The EM drive effort itself is a test to see which of them, if any, might suggest a deeper understanding of how the world works. Here's where your elemental question comes into play.QuoteOnce more DIY builds are done. I hope sometime in the future, that the EXACT same size/shape EM Drive cavities are compared say copper to aluminum. Just to see if somehow if the elements that comprise the EM Drive cavity have any influence with thrust measurements.
Traditionally, copper is often chosen because it's a good combination of being a great conductor while also being cheap. When reflecting/containing EM energy, as is the case of EM drive resonance chamber, you want a good conductor (silver is actually best, but good luck trying to get your boss to pay for that!). Think of it as a good mirror in a setup where you're trying to contain visible light. Glass is a good insulator but allows for a lot of EM energy to escape the chamber.
This, however, is already well understood. Maxwells equations, tedious though they may be, are well understood; as are 'real' photons. What's not well understood is how 'virtual' photons may interact with anything. A real photon might not care what kind of atom emits it, but a virtual photon might. Or the virtual photons might simply interact with Earth's mag field, or space-time itself or who-knows-what in some unforeseen way.
Building multiple setups using different materials is therefore a very good idea because there's no real way it can go wrong. If we see a notable difference, then we might get a better idea of where to look more closely. If we see little or no difference, it might tell us that we've simply overlooked something a-la-pioneer anomaly. Personally, I think Stephen Hawking has the best philosophy about this sort of thing. Bet safe (i.e., we've just overlooked something) and you'll probably be right. But if you're not, you'll be so excited about the new outcome that you won't care that you were wrong. -
#2736 by SeeShells on 10 Feb, 2016 05:05
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This, at least from a 'normal, currently understood' standpoint, I can answer. Your questions themselves are a bit loaded however, when you say 'photon'. But first things first,
I have an odd question. Maybe Dr. Rodal and/or others can help.
While I understand that a photon has no rest mass.
Is there a maximum mass when a photon is moving at or near the speed of light and does it vary by what element the photon was created from?
Photons never have mass, only energy. Although the line between mass and energy becomes blurred in regimes where relativistic effects dominate (e.g. black holes), for 'normal' purposes photons always have zero mass. By consequence of the standard model, particles of zero mass must travel at lightspeed; and therefore:QuoteExample: Is there some sort of advantage of photons being created by copper atoms in a EM Drive caused by RF frequency excitement, over other metals or even other elements? As far as having a greater mass when traveling at or near light speed than say atoms being excited in a aluminum EM Drive cavity producing photons. When they are moving at or near light speed?
If there is? Are there any atoms that would have substantial benefits over copper atoms as far as the mass of photons traveling at or near light speed, created based on being excited in a EM Drive cavity by forces like RF frequencies?
Just wondering why copper seems to be a overwhelming, choice to use when creating EM Drives?
photons are elementally agnostic, which is to say a 5eV photon emitted from copper is indistinguishable from a 5eV photon emitted from aluminum, or anything else. Both travel AT lightspeed, and have the same energy; and if you do know a way to tell the two apart, then PM me because we're going to make a lot of money.
The thing is, your questions, as they pertain to EM drives, don't actually have anything to do with photons. You're asking about interactions between E&M fields at the boundary between empty space and bulk material, and that's a whole different beast. The word 'photon' implies a free-space, propagating solution to Maxwell's equations; and that's a very small subset of all possible solutions. Photons are a 'far field' construct, which is to say they're only well defined far away from the source that created them.
Quantum mechanically, this should be stated to be a 'real' photon, which has a real associated wavelength, real energy, and has a real/long lifetime. However, with an EM frustum, there really is no appreciable far field because your EM energy is confined to a space that's only a couple wavelengths long; if even that. Most interactions are therefore near-field, where 'normal' photons have no well-determined definition. Within the frustum, so-called virtual photons become important.
Virtual photons are also not well defined (nor well named, for that matter) but can be roughly thought of as a quantum field equivalent to evanescent/reactive/whatever solutions to traditional EM fields. They have a heavy presence near the 'source' of their generation, and rapidly lose importance the farther away from that source you go. All you need to know is that depending on the framework of your definition for virtual photons, they're allowed to interact with surrounding 'stuff' in ways that maxwells equations alone do not. Many such theoretical frameworks exist. The EM drive effort itself is a test to see which of them, if any, might suggest a deeper understanding of how the world works. Here's where your elemental question comes into play.QuoteOnce more DIY builds are done. I hope sometime in the future, that the EXACT same size/shape EM Drive cavities are compared say copper to aluminum. Just to see if somehow if the elements that comprise the EM Drive cavity have any influence with thrust measurements.
Traditionally, copper is often chosen because it's a good combination of being a great conductor while also being cheap. When reflecting/containing EM energy, as is the case of EM drive resonance chamber, you want a good conductor (silver is actually best, but good luck trying to get your boss to pay for that!). Think of it as a good mirror in a setup where you're trying to contain visible light. Glass is a good insulator but allows for a lot of EM energy to escape the chamber.
This, however, is already well understood. Maxwells equations, tedious though they may be, are well understood; as are 'real' photons. What's not well understood is how 'virtual' photons may interact with anything. A real photon might not care what kind of atom emits it, but a virtual photon might. Or the virtual photons might simply interact with Earth's mag field, or space-time itself or who-knows-what in some unforeseen way.
Building multiple setups using different materials is therefore a very good idea because there's no real way it can go wrong. If we see a notable difference, then we might get a better idea of where to look more closely. If we see little or no difference, it might tell us that we've simply overlooked something a-la-pioneer anomaly. Personally, I think Stephen Hawking has the best philosophy about this sort of thing. Bet safe (i.e., we've just overlooked something) and you'll probably be right. But if you're not, you'll be so excited about the new outcome that you won't care that you were wrong.
You need a like for this post.
To explain something in a clear simple way (unless we going into quantum physics then all bets are off) shows a good understanding of the subject and you did a very nice job of it.
You brief write up on what I've seen inside of the drive cavity is spot on. I remember asking months ago WarpTech
http://emdrive.wiki/Todd_Desiato_(@WarpTech)%27s_Evanescent_Wave_Theory
(who is very much missed) just where did evanescent waves exist in the cavity and his answer became a epiphany for me as here was the red flag that stepped outside the boundaries of Maxwell. Evanescent modes are characterized by an exponential attenuation and lack of a phase shift and that lack of phase shift has made me go, now that's a interesting thing to be happening in the cavity.
Nice post, enjoyed reading.
Shell -
#2737 by dustinthewind on 10 Feb, 2016 06:42
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...
You need a like for this post.
To explain something in a clear simple way (unless we going into quantum physics then all bets are off) shows a good understanding of the subject and you did a very nice job of it.
You brief write up on what I've seen inside of the drive cavity is spot on. I remember asking months ago WarpTech
http://emdrive.wiki/Todd_Desiato_(@WarpTech)%27s_Evanescent_Wave_Theory
(who is very much missed) just where did evanescent waves exist in the cavity and his answer became a epiphany for me as here was the red flag that stepped outside the boundaries of Maxwell. Evanescent modes are characterized by an exponential attenuation and lack of a phase shift and that lack of phase shift has made me go, now that's a interesting thing to be happening in the cavity.
Nice post, enjoyed reading.
Shell
It is a fascinating property if it really exceeds the speed of light. It almost reminds me of looking at the tip of an iceberg and then the current starts flowing the iceberg starts to rise out of the water. It also reminds me of an article I have seen that suggested quantum information seems to exchange faster than light. Took me a while to find it but I think this was it: http://physicsworld.com/cws/article/news/2008/aug/13/entanglement-remains-a-mystery . Some more recent news seems to suggest hidden variables or maybe some hidden underlying structure? http://physicsworld.com/cws/article/news/2015/mar/30/entangled-photons-cast-a-new-light-on-cause-and-effect -
#2738 by Prunesquallor on 10 Feb, 2016 11:19
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I only know of one person right now at jpl. They are at a low level and he publicly disregards anything to do with the emdrive (via a forum nickname). Based on that one perspective alone, I view them as wanting to play it safe with older, proven technology. Lip service is my guess but we can hope for the opposite.Tangent Alert - JPL's past present and future (on propulsion)
Recently, JPL has branched out by hiring climatologists as they continue to expand on their original purpose for NASA. However, a 2014 video does lay out some future plans regarding space propulsion. As you probably already know, they are 100% behind classic rocket propulsion, but the speaker does mention "something else" towards the end...
If you are wondering if they would be/are supportive of EMDrive research or testing, its probably best if you view the video...a total about 90 minutes. The first hour is simply a JPL history lesson. Future propellant considerations include green fuel and "something else".
Really like the mention on Nuclear Thermal. I only hope this isnt just lip service. We could colonize our solar system with a mixture of VASIMIR, Fusion Rockets, and Nuclear Thermal
If when you say "older proven tech" you mean standard rocket equation based propulsion. Then I have no problems with that. Like I said I think it is perfectly possible for us to economically colonize the entire solar system with rocket based propulsion. But Chemical Rockets need to be retired or at the very least be limited to Earth to orbit scenarios and attitude control. Though I am not sure they are even needed for attitude control, since you could use gyros to accomplish the same thing.
We need strong investment in Space based nuclear power reactors. Which will enable Vasimr which is honestly a vast leap over current ion drive capabilities. With the additional bonus of providing power for long term manned deep space travel. In parallel, Nuclear Fission Thermal Rockets and longer term work on Nuclear Fusion Rockets.
Agree with your space nuclear comments, but as many know, VASIMR must be taken with a huge chunk of salt. Not only does it need megawatts of power (for manned applications) but this power source must be orders of magnitude lighter in weight than even the most advanced credible nuclear concepts. -
#2739 by rfmwguy on 10 Feb, 2016 12:46
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I don't know about anyone else, but I've just read one of the best posts I can recall for a while. @1, don't stray too far. It is clear you have a personal understanding of physics and have the skill to communicate effectively. That is severely lacking in most online venues. Well done. We have no gold stars, but I've invented a virtual one for you.
which I had not previously seen.
