-
#820 by Monomorphic on 13 Aug, 2017 22:04
-
There was a huge safety problem with the test stand on the work bench. The center of gravity was so high that the entire experiment almost tipped over once, spilling the antifreeze dampening fluid all over the floor and shattering the glass reservoir. I was also quickly running out of usable bench top space. So I built a robust, dedicated, and maneuverable test stand. The center of gravity was greatly reduced, leading to a much more stable base structure for experiments.
-
#821 by Dagger on 13 Aug, 2017 23:35
-
Anyone seen the new TV show Salvation? They are actually planning on using an EmDrive to save earth from an asteroid impact
-
#822 by sanman on 14 Aug, 2017 05:41
-
Anyone seen the new TV show Salvation? They are actually planning on using an EmDrive to save earth from an asteroid impact
Hehe, yeah I know - there's a thread on that show in the Spaceflight Entertainment and Hobbies forum.
You'll notice that the EMdrive on the TV show doesn't look like the real-life EMdrive, and instead looks more like a sci-fi notion of a hi-tech rocket engine. They take a lot of liberties with science of course - like showing video from a Jupiter probe arriving in realtime without any signal delay.
Lots of suspense and plot twists in this show though, which makes it very entertaining.
Just remember - "whoever controls the EMdrive controls the fate of the planet"
-
#823 by dustinthewind on 14 Aug, 2017 13:13
-
What I'm envisioning is the superposition of two counterpropagating, non-identical (in this case amplitude but in another model you can create beats using two different frequencies...like with a red and green laser in a common medium....but the guys using magnetrons are putting wide band noise into their cavities of multiple frequencies too) electromagnetic waves, the result is a partial standing wave. The partial standing wave is what's important. If I understand things correctly, of course one photon is massless, but a system of two nonparallel photons has a real mass. I envision that this partial standing wave is in fact massive, and it's the jerking motion of this massive wave that is responsible for gravitational induction (AC gravity...changing gravity...changing acceleration) and these disturbances in the gravitational field are propagating away, carrying away energy and momentum from the cavity (maximum theoretical Q? Instead of trying to directly measure gravitational radiation which is extremely difficult right now, maybe find the missing Q instead) asymmetrically (because of the octupole shape of the cavity). It isn't good enough to just accelerate a mass and achieve gravitational radiation because gravitational dipole radiation cannot exist. You have to have a changing acceleration. It seems to me that you don't need a planet sized mass or energy equivalent, you just need to interfere waves and switch things really quickly (we want the gravitomagnetic flux to be changing quickly) to be able to induce alternating gravitational fields. This isn't "warp drive" in my view. I don't believe that gravitoelectromagnetism is pseudoscience anymore since Gravity Probe B was able to measure the Earth's gravitational magnetic component, and also with the confirmation of gravitational waves, the gravitational equivalent of electrodynamics must be more a true reality than just equations on paper. Just imagine the impact to the world, and the potential gains, that would come from mastering gravitodynamics, as we have with electrodynamics.
I had made a suggestion a while about about submersing the EM drive in water and powering it while monitoring the increase in temperature of the water and the energy put in, in order to observe some missing energy. Such energy may be being carried off by something else that was escaping the cavity.
On the other hand, WarpTech suggesting some imbalance in heat dissipation inducing some propulsion effect, leaves me unsure it would detect missing thermal energy in that case or not.
If there was missing energy then the idea was to accumulate a fair amount of energy and some missing energy accumulated over time should be measurable. However this depends on our measuring instruments and the amount of missing energy.
-
#824 by Rodal on 14 Aug, 2017 13:15
-
This show is freely available on Amazon Prime.Anyone seen the new TV show Salvation? They are actually planning on using an EmDrive to save earth from an asteroid impact
Hehe, yeah I know - there's a thread on that show in the Spaceflight Entertainment and Hobbies forum.
You'll notice that the EMdrive on the TV show doesn't look like the real-life EMdrive, and instead looks more like a sci-fi notion of a hi-tech rocket engine. They take a lot of liberties with science of course - like showing video from a Jupiter probe arriving in realtime without any signal delay.
Lots of suspense and plot twists in this show though, which makes it very entertaining.
Just remember - "whoever controls the EMdrive controls the fate of the planet"
The depiction of student life at MIT is unrealistic, the interior of the buildings, the lecture halls, the pubs, the ambience and the student life does not bear much resemblance to the real MIT.
It is interesting how Hollywood's idea of scientists/engineers has morphed from the "evil scientist" of the 1930's-1950's movies
to this new Hollywood "tech person" that seems to be based around Hollywood's idea of Mark Zuckerberg's Facebook and other social-media ventures.
After watching the beginning of the first episode I asked myself: do I really want to sit through all the predictable plot twists and human relationships just to get to the good part? My answer: no
The predictable plot and human relationship twists have been done so many times before (and often much better) that giving up an hour of our time to lose it forever seems too much. The MIT student falls in love in 24 hours, and this gives him even more the reason to save the planet. The dialog, the script, are clunky. I just did not find it interesting.
-
#825 by dustinthewind on 14 Aug, 2017 13:18
-
....
Thanks for this! This really crystallized something for me.
And most of all that they would be possible with the really tiny energy in the EM Drive. Remember that E=Mc2, therefore the equivalent mass of the electromagnetic energy in the EM Drive, M=E/c2 is really tiny.
....
Going back to first principles, even allowing for some order of magnitude increases due to Compton scattering, etc. there is no way you can get anywhere near newton levels of thrust just by the energy introduced into the fustrum.
Therefore, if there is anything to this, thrust must be a second order effect of something caused by the asymmetry intruduced by the fustrum. (And sincere apologies if this has been obvious to everyone except me!)
A fan with only 8.95 Watts input power can produce 204 milliNewtons (0.204 Newtons) of force
https://www.wired.com/2012/09/modeling-the-force-from-a-fan/
this is due to the force from air convection
204 milliNewtons/0.00895 kW = 22,793 mN/kW
for comparison Shawyer claimed 100 times less: up to 243 mN/kW for the Demonstrator, this is the reason why it is conceivable that convection forces may play a role in the claimed results, and why it is important to run the experiments in a vacuum chamber (like NASA and TU Dresden) to eliminate thermal convection effects. You also have Lorentz forces and thermal expansion forces (shift of center of mass in the pendulum setup) still present in a vacuum.
One of the reasons I was suggesting a resonant osculating pendulum test was to help eliminate those air convection problems. Thermal air convection should be reduced some what if the rate of change in thermal energy doesn't match the frequency of the pendulum or rather has its change in amplitude reduced. (i.e. thermal equilibrium should reduce the effects some what). Keeping the cavity at a constant thermal temperature was the idea while still applying periodic resonant thrust pulses to the underdamped pendulum. Massive cavities might be the better bet here, less rapid change in thermal amplitude over time.
Another idea was to enclose the cavity in an insulated box that moved with it. Any momentum conveyed to the air in the box remains with the cavity, unable to escape and convey unwanted momentum to the cavity. Unless what escapes is escaping from the box. -
#826 by TheTraveller on 14 Aug, 2017 13:51
-
EmDrive thruster efficiency presentation.
Soon to be on the emdrive.com web site
-
#827 by Flyby on 14 Aug, 2017 14:16
-
Quote
Typical 3G thruster efficiencies are between 20% and 70%, in order to optimise the flight envelope for each application
Typical?
what typical? Where typical?
we have yet to see anything that works, let alone give it a study on "typical efficiency"...
Perhaps when if you speak of the "typical efficiency" of an internal combustion engine, I'll be more inclined to follow the reasoning, since it exists since 1876. Lot's of prototypes and production models to evaluate there...
But there really is everything BUT a "typical efficiency" about the EMdrive...
The topic of "highly controversial" should have a higher priority maybe?
Unless the numbers relate to real world experiments and results, calculating efficiencies based upon thought-experiments doesn't have a substantial purpose or meaning...
iow, let us first see a working device and then we can start talking about efficiencies...
This really is as the saying goes :
-
#828 by SeeShells on 14 Aug, 2017 14:33
-
Dr. Rodal,
This show is freely available on Amazon Prime.Anyone seen the new TV show Salvation? They are actually planning on using an EmDrive to save earth from an asteroid impact
Hehe, yeah I know - there's a thread on that show in the Spaceflight Entertainment and Hobbies forum.
You'll notice that the EMdrive on the TV show doesn't look like the real-life EMdrive, and instead looks more like a sci-fi notion of a hi-tech rocket engine. They take a lot of liberties with science of course - like showing video from a Jupiter probe arriving in realtime without any signal delay.
Lots of suspense and plot twists in this show though, which makes it very entertaining.
Just remember - "whoever controls the EMdrive controls the fate of the planet"
The depiction of student life at MIT is unrealistic, the interior of the buildings, the lecture halls, the pubs, the ambience and the student life does not bear much resemblance to the real MIT.
It is interesting how Hollywood's idea of scientists/engineers has morphed from the "evil scientist" of the 1930's-1950's movies
to this new Hollywood "tech person" that seems to be based around Hollywood's idea of Mark Zuckerberg's Facebook and other social-media ventures.
After watching the beginning of the first episode I asked myself: do I really want to sit through all the predictable plot twists and human relationships just to get to the good part? My answer: no
The predictable plot and human relationship twists have been done so many times before (and often much better) that giving up an hour of our time to lose it forever seems too much. The MIT student falls in love in 24 hours, and this gives him even more the reason to save the planet. The dialog, the script, are clunky. I just did not find it interesting.
Just when did Hollywood hype mirror the real world?
For me this is a great tool to raise the general awareness to advancing real world research even if it's through the rose colored glasses of a bad studio production.
Had a friend tell my I needed more lights to look at when i showed him my test bed. Really?
-
#829 by Rodal on 14 Aug, 2017 14:39
-
...
I did not expect this series to be like a great movie, with interesting plot and script, as say, Ex Machina or the classic Blade Runner, that really holds your interest.
Dr. Rodal,
Just when did Hollywood hype mirror the real world? For me this is a great tool to raise the general awareness to advancing real world research even if it's through the rose colored glasses of a bad studio production.
Had a friend tell my I needed more lights to look at when i showed him my test bed. Really?
But even the low budget, comic, Iron Sky could hold my interest through the end.
Yes, I know, this is a TV show, but again, the production values, characters, plot and script does not even come close to say, for example TV shows like Fargo (particularly seasons I and II), where you are often surprised, and are always looking forward to the next show, instead of asking yourself: why I am sitting here watching this instead of ...
And I know that Fargo is not a science-fiction show (but it had flying saucers
), but I recall when the original Twilight Zone (late 50's early 60's) amazed me and still like watching Twilight Zone reruns during the SyFy channel Marathons... Some of the best episodes were less than half an hour long...
Concerning a better, more interesting (of course never perfect, as reality is often boring ) description of MIT, I would mention the movie 21 (https://en.wikipedia.org/wiki/21_(2008_film)), the movie A Beautiful Mind (https://en.wikipedia.org/wiki/A_Beautiful_Mind_(film)) and the movie Good Will Hunting ( https://en.wikipedia.org/wiki/Good_Will_Hunting), yes the writers took many liberties to depict those stories, but still, they made a much greater effort than in Salvation...
-
#830 by SeeShells on 14 Aug, 2017 15:09
-
Very true, It's not Stanley Kubrick's 2001, which set the standard for not only visual effects and plot interpretation, but it also set the bar for the designs of ships and interest in space travel....
I did not expect this series to be like a great movie, with interesting plot and script, as say, Ex Machina or the classic Blade Runner, that really holds your interest.
Dr. Rodal,
Just when did Hollywood hype mirror the real world? For me this is a great tool to raise the general awareness to advancing real world research even if it's through the rose colored glasses of a bad studio production.
Had a friend tell my I needed more lights to look at when i showed him my test bed. Really?
But even the low budget Iron Sky could hold my interest through the end.
Yes, I know, this is a TV show, but again, the production values, characters, plot and script does not even come close to say, for example shows like Fargo (particularly seasons I and II), where you are often surprised, and are always looking forward to the next show, instead of asking yourself: why I am sitting here watching this instead of ...
And I know that Fargo is not a science-fiction show, but I recall when the original Twilight Zone (late 50's early 60's) amazed me and still like watching Twilight Zone reruns during the SyFy channel Marathons... Some of the best episodes were less than half an hour long...
I even used the 2001's Moon Bus modified to present the idea of exploration on a planetary surface without disturbing the surface like our current set of planetary rovers. Instead of using the newer potential set of engines like the MEGA and EMDrive or others for huge rocket ships or interstellar probes I wanted to show a more mundane application.
That said, I think I'll Que up watching 2001 a Space Odyssey again and get cold chills from Johann Strauss's Blue Danube.
My Very Best,
Shell
PS: I'm still here and still working on the "new" project.
-
#831 by TheTraveller on 14 Aug, 2017 15:32
-
Roger's email:
Hi Phil
As a follow up to my last email, I have attached a short presentation on how we calculate thruster efficiency.
I will get this put on our web site, so feel free to share it. Hopefully it will settle the over-unity arguments that still seem to persist in the forums.
Best regards
Roger -
#832 by Jim Davis on 14 Aug, 2017 15:44
-
From the FAQ on emdrive.com:
"Q. Does the theory of the EmDrive contravene the accepted laws of physics or electromagnetic theory?
A. The EmDrive does not violate any known law of physics."
How can this be?
Suppose you have a 1000 kg vehicle propelled by an EmDrive.
In one frame of reference the vehicle accelerates from 0 m/s to 1 m/s. An observer in this frame of reference concludes that the EmDrive must have consumed a minimum of ((1000)*(1)^2)/2 - ((1000)*(1)^2)/2 = 500 J.
In another frame of reference the vehicle accelerates from 10 m/s to 11 m/s. An observer in this frame of reference concludes that the EmDrive must have consumed a minimum of ((1000)*(11)^2)/2 - ((1000)*(10)^2)/2 = 10,500 J.
Energy is not being conserved.
I know this is the 10th thread and this has probably been covered previously but it seems that there are only two positions a reasonable person can take:
1.) The EmDrive does not work; the observed effects are all within experimental error.
2.) The EmDrive works; all errors have been accounted for; energy and momentum are not conserved.
Does anyone hold the position:
3.) The EmDrive works; all errors have been accounted for; energy and momentum are conserved.
If so, can you explain how? -
#833 by TheTraveller on 14 Aug, 2017 16:47
-
From the FAQ on emdrive.com:
"Q. Does the theory of the EmDrive contravene the accepted laws of physics or electromagnetic theory?
A. The EmDrive does not violate any known law of physics."
How can this be?
Suppose you have a 1000 kg vehicle propelled by an EmDrive.
In one frame of reference the vehicle accelerates from 0 m/s to 1 m/s. An observer in this frame of reference concludes that the EmDrive must have consumed a minimum of ((1000)*(1)^2)/2 - ((1000)*(1)^2)/2 = 500 J.
In another frame of reference the vehicle accelerates from 10 m/s to 11 m/s. An observer in this frame of reference concludes that the EmDrive must have consumed a minimum of ((1000)*(11)^2)/2 - ((1000)*(10)^2)/2 = 10,500 J.
Energy is not being conserved.
I know this is the 10th thread and this has probably been covered previously but it seems that there are only two positions a reasonable person can take:
1.) The EmDrive does not work; the observed effects are all within experimental error.
2.) The EmDrive works; all errors have been accounted for; energy and momentum are not conserved.
Does anyone hold the position:
3.) The EmDrive works; all errors have been accounted for; energy and momentum are conserved.
If so, can you explain how?
Why stop there? What about:
100 m/s to 101 m/s? or
1,000 m/s to 1,001? m/s or
10,000 m/s to 10,001 m/s? or
100,000 m/s to 100,001 m/s, etc?
Then explain how mass in space knows it's relative velocity to another frame so it knows now much work is needed to be done on it to move it's mass some other frame relative distance?
What is known is a = f/m works in the frame of the accelerating EmDrive. -
#834 by Jim Davis on 14 Aug, 2017 17:33
-
Why stop there?
Because I thought the point was adequately made.QuoteThen explain how mass in space knows it's relative velocity to another frame so it knows now much work is needed to be done on it to move it's mass some other frame relative distance?
If energy and momentum are conserved, the mass doesn't have to know; the work needed will be the same in all frames of reference. This is the case with all means of propulsion hitherto, but not the EmDrive apparently.
But just to be clear:
Am I correct in concluding that you're in the
2.) The EmDrive works; all errors have been accounted for; energy and momentum are not conserved.
cohort?
-
#835 by Bob012345 on 14 Aug, 2017 17:43
-
Very true, It's not Stanley Kubrick's 2001, which set the standard for not only visual effects and plot interpretation, but it also set the bar for the designs of ships and interest in space travel....
I did not expect this series to be like a great movie, with interesting plot and script, as say, Ex Machina or the classic Blade Runner, that really holds your interest.
Dr. Rodal,
Just when did Hollywood hype mirror the real world? For me this is a great tool to raise the general awareness to advancing real world research even if it's through the rose colored glasses of a bad studio production.
Had a friend tell my I needed more lights to look at when i showed him my test bed. Really?
But even the low budget Iron Sky could hold my interest through the end.
Yes, I know, this is a TV show, but again, the production values, characters, plot and script does not even come close to say, for example shows like Fargo (particularly seasons I and II), where you are often surprised, and are always looking forward to the next show, instead of asking yourself: why I am sitting here watching this instead of ...
And I know that Fargo is not a science-fiction show, but I recall when the original Twilight Zone (late 50's early 60's) amazed me and still like watching Twilight Zone reruns during the SyFy channel Marathons... Some of the best episodes were less than half an hour long...
I even used the 2001's Moon Bus modified to present the idea of exploration on a planetary surface without disturbing the surface like our current set of planetary rovers. Instead of using the newer potential set of engines like the MEGA and EMDrive or others for huge rocket ships or interstellar probes I wanted to show a more mundane application.
That said, I think I'll Que up watching 2001 a Space Odyssey again and get cold chills from Johann Strauss's Blue Danube.
My Very Best,
Shell
PS: I'm still here and still working on the "new" project.
And Kubrick have us more than a millisecond to enjoy such scenes too! -
#836 by Bob012345 on 14 Aug, 2017 18:14
-
From the FAQ on emdrive.com:
"Q. Does the theory of the EmDrive contravene the accepted laws of physics or electromagnetic theory?
A. The EmDrive does not violate any known law of physics."
How can this be?
Suppose you have a 1000 kg vehicle propelled by an EmDrive.
In one frame of reference the vehicle accelerates from 0 m/s to 1 m/s. An observer in this frame of reference concludes that the EmDrive must have consumed a minimum of ((1000)*(1)^2)/2 - ((1000)*(1)^2)/2 = 500 J.
In another frame of reference the vehicle accelerates from 10 m/s to 11 m/s. An observer in this frame of reference concludes that the EmDrive must have consumed a minimum of ((1000)*(11)^2)/2 - ((1000)*(10)^2)/2 = 10,500 J.
Energy is not being conserved.
I know this is the 10th thread and this has probably been covered previously but it seems that there are only two positions a reasonable person can take:
1.) The EmDrive does not work; the observed effects are all within experimental error.
2.) The EmDrive works; all errors have been accounted for; energy and momentum are not conserved.
Does anyone hold the position:
3.) The EmDrive works; all errors have been accounted for; energy and momentum are conserved.
If so, can you explain how?
I think it's way too soon to have absolutely firm opinions. The EMDrive seems to work. I don't think it's fair to say #1 or #2 or #3. People don't have to have a complete understanding of how momentum and energy are conserved in this system to proceed with experiments based on the preliminary data that purportedly shows such effects in EmDrive systems. I would say it this way;
The EMDrive seems to work, at least some data is suggestive enough to keep testing it. Thus people here and elsewhere are doing so. There is plenty of ongoing debate over the issues of the conservation laws as there should be.
As for the MEGA drive, there is data suggesting that works too. Enough for serious study. There is good reason to think of the force on the MEGA drive as an external force due to Mach effects. If we think of it as an external force, we don't have to agonize over local momentum conservation. And the kinetic energy is ultimately caused by the agent of the external force.
Some people think that the EMDrive may also actually be using the Mach effect in an as yet not understood way. There are other ideas as well. Alternativly, the forces on the EMDrive may also be argued to be external caused by an external agent thus mitigating the concerns over conservation laws.
p.s. The different observers in your example would see the same difference with a rocket doing a burn. Kinetic energy of a rocket alone is not a conserved quantity. In that case if we include the kinetic energy change of the exhaust, we discover the net change in energy is the same for both observers. If we assume local momentum is conserved in the EMDrive, we can also assume there is an as yet unknown mechanism functioning like the exhaust, carrying the momentum away and balancing the energy. If the energy comes from an external agent, it is accounted for that way and momentum is not conserved locally. Either way, if it works, I'll take it!
-
#837 by TheTraveller on 14 Aug, 2017 18:51
-
In the presentation Roger is using EmDrive relative velocity change, which can be calculated for that frame by measuring acceleration vs time and calculating the resultant velocity change.
Doing that Roger shows CofE is conserved.
-
#838 by PotomacNeuron on 14 Aug, 2017 18:53
-
Why stop there?
Because I thought the point was adequately made.QuoteThen explain how mass in space knows it's relative velocity to another frame so it knows now much work is needed to be done on it to move it's mass some other frame relative distance?
If energy and momentum are conserved, the mass doesn't have to know; the work needed will be the same in all frames of reference. This is the case with all means of propulsion hitherto, but not the EmDrive apparently.
But just to be clear:
Am I correct in concluding that you're in the
2.) The EmDrive works; all errors have been accounted for; energy and momentum are not conserved.
cohort?
Welcome to the forum. I am in the 1) cohort. I am one of a few that are paranoid enough not to leave the forum. Without us, you will not know that there are other opinions other than those held by the 2) or 3) cohort. -
#839 by TheTraveller on 14 Aug, 2017 19:28
-
Why stop there?
Because I thought the point was adequately made.QuoteThen explain how mass in space knows it's relative velocity to another frame so it knows now much work is needed to be done on it to move it's mass some other frame relative distance?
If energy and momentum are conserved, the mass doesn't have to know; the work needed will be the same in all frames of reference. This is the case with all means of propulsion hitherto, but not the EmDrive apparently.
But just to be clear:
Am I correct in concluding that you're in the
2.) The EmDrive works; all errors have been accounted for; energy and momentum are not conserved.
cohort?
Welcome to the forum. I am in the 1) cohort. I am one of a few that are paranoid enough not to leave the forum. Without us, you will not know that there are other opinions other than those held by the 2) or 3) cohort.
Hi PN,
Roger clearly shows now, using EmDrive reference frame velocity changes, CofE is conserved.
So no OU.
For me this is a great tool to raise the general awareness to advancing real world research even if it's through the rose colored glasses of a bad studio production. 
), but I recall when the original Twilight Zone (late 50's early 60's) amazed me and still like watching Twilight Zone reruns during the SyFy channel Marathons... Some of the best episodes were less than half an hour long...