Author Topic: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive  (Read 192368 times)

Offline FutureStormtrooper

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #160 on: 05/01/2015 12:32 AM »
There are people who believe this is an incredibly exciting, civilization-changing breakthrough, and there are people who believe that it's all pseudo-scientific bunk. But in the interim, both opinions mean far less than the fact that regardless of this spirited, generally well-meaning debate, there are people who are continuing to do these experiments, and that data is being generated, and that sooner or later we will know the truth of the matter once and for all.

I encourage everybody to keep that in the forefront of their mind while reading all threads related to this research.
« Last Edit: 05/01/2015 12:33 AM by FutureStormtrooper »

Offline Prunesquallor

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #161 on: 05/01/2015 01:27 AM »
Is the trip time to alpha centauri based on the space drive, or based on the power source?

The Joosten/White IEEE paper shows that constant spacecraft acceleration of around 0.001 g should be possible with Q-Thruster performance of 0.4 N/kWe and reasonable power plant and thruster masses.  The interstellar trip times merely reflect that constant acceleration.  Those computations are quite straightforward, as special relativity as opposed to general relativity can be used, even for the decelerated case.

It ignores the "paradox velocity".
Retired, yet... not

Offline Robotbeat

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #162 on: 05/01/2015 03:05 AM »
Is the trip time to alpha centauri based on the space drive, or based on the power source?

The Joosten/White IEEE paper shows that constant spacecraft acceleration of around 0.001 g should be possible with Q-Thruster performance of 0.4 N/kWe and reasonable power plant and thruster masses.  The interstellar trip times merely reflect that constant acceleration.  Those computations are quite straightforward, as special relativity as opposed to general relativity can be used, even for the decelerated case.

It ignores the "paradox velocity".
Of course, your kinetic energy would be ridiculously high, thousands of times greater than the energy you put into the drive.

For .4N/kW and 40kg/kW specific power for a 1kW craft (weighing 40kg) just to make things easy:

(Kinetic Energy)/(Energy input)=
(.5*40kg*(92years*.4N/kW/(40kg/kW))^2)/(1kW*92years)
=
5806.5

Make no mistake, this is also a method to gain free energy.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline Robert Thompson

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #163 on: 05/01/2015 03:11 AM »
imho I never read the EM drive / Star Trek threads. (I promise myself) I'll truncate my reading of EM stuff here.

 :-\ Do the experiment in heavily shielded containment. In vacuum. Suspended vertically by strong supple inelastic wire from a motion-isolated framework. Covered in temperature and vibration sensors. Motions measured to the nanometer by laser. For thousands of hours. In multiple orientations. Thoroughly probe the parameter space of earth rotation and revolution (first order). Latitude, longitude, altitude, pressure, temperature, humidity, local and global magnetic field, local seismic conditions, tidal/quadrupole orientations of sun, moon, Jupiter. (Second order) What were the galactic/cosmological position and momentum space of every experiment performed so far? Any commonalities from a galactic/cosmological framework.

Synanpses are cheap, digital text is cheap, broad constituencies of imaginations fired by evocative riddles are cheap - that's all a net gain. It also reflects well that a technical problem can be intensively crowd sourced, cheaply. A utility or discovery or success will be located more quickly by crowd source. A futility or lesson or failure will be located more quickly by crowd source. In either case, Mr Spock would (I wager) say NSF is "one" logical place to piranha-ize or sigma clip radical claims, pertaining to space flight, involving NASA employees, that have at least the basis of hardware and data. (Cosmoquest has an advanced topics thunderdome, for another.)  :) /imho

Offline Robotbeat

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #164 on: 05/01/2015 03:16 AM »
Yeah... I'm not getting how this does not violate conservation of momentum and energy. For example if this works you should be able to construct a perpetual motion free energy machine. If constant electrical power produces constant acceleration you have a problem since kinetic energy increases with the square of velocity. You will quickly reach a point where your kinetic energy vastly exceeds the electrical energy input.

Sorry, I smell the stench of cold fusion.
Much worse than cold fusion, IMHO. At least with cold fusion, you're still conserving momentum and energy.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline ppnl

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #165 on: 05/01/2015 04:01 AM »
There are people who believe this is an incredibly exciting, civilization-changing breakthrough, and there are people who believe that it's all pseudo-scientific bunk. But in the interim, both opinions mean far less than the fact that regardless of this spirited, generally well-meaning debate, there are people who are continuing to do these experiments, and that data is being generated, and that sooner or later we will know the truth of the matter once and for all.

I encourage everybody to keep that in the forefront of their mind while reading all threads related to this research.

The thing to keep at the forefront of your mind is that decades after the first claim of cold fusion there are people still "generating data" and "doing experiments".  It seems like every few years there is a new wave of results. Tech dirt was hyping the latest just last year I think. Every few years Rossi produces a new E-cat that he shops around. Decades from now people will still be debating the EM-drive along with the E-cat. Desire produces suspension of disbelief. That suspension hides the monstrous improbability of the claims. You really are the easiest person for you to fool.

Offline FutureStormtrooper

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #166 on: 05/01/2015 04:16 AM »
The thing to keep at the forefront of your mind is that decades after the first claim of cold fusion there are people still "generating data" and "doing experiments".  It seems like every few years there is a new wave of results. Tech dirt was hyping the latest just last year I think. Every few years Rossi produces a new E-cat that he shops around. Decades from now people will still be debating the EM-drive along with the E-cat. Desire produces suspension of disbelief. That suspension hides the monstrous improbability of the claims. You really are the easiest person for you to fool.

Paul March has been very forthcoming on NSF with experimental setup and data, allowing other experts to cross-check both and suggest possible sources of error. Other groups and individuals have been setting up similar experiments to further the body of data available. This isn't some conspiracy where one individual or small group has a financial incentive to fool the world. Either usable thrust is being generated, or it isn't; one way or another we will know in time.

Online sanman

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Offline CW

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #168 on: 05/01/2015 06:17 AM »
The beauty of reality is that it doesn't give a damn about personal opinions. Accepted physics was derived from observations, hypotheses, real-world experimentation and falsification attempts. I recommend letting the Eagleworks team do what they do, collect experimental data and compare them to their predictions. When there comes a point that there seems to be conclusive evidence, I recommend Eagleworks to compile a detailed HOWTO replicate those setups for just about anybody on the planet to repeat the experiment(s). Prolonging the current non-expedient bickering about whether or not this adheres to 'known' physics is truly pointless. Multiple experiments already showed that something happens.

The right thing to do is to follow the data. Personal opinions don't mean anything.
« Last Edit: 05/01/2015 06:31 AM by CW »
Reality is weirder than fiction

Offline Star One

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #169 on: 05/01/2015 06:26 AM »

The thing to keep at the forefront of your mind is that decades after the first claim of cold fusion there are people still "generating data" and "doing experiments".  It seems like every few years there is a new wave of results. Tech dirt was hyping the latest just last year I think. Every few years Rossi produces a new E-cat that he shops around. Decades from now people will still be debating the EM-drive along with the E-cat. Desire produces suspension of disbelief. That suspension hides the monstrous improbability of the claims. You really are the easiest person for you to fool.

Paul March has been very forthcoming on NSF with experimental setup and data, allowing other experts to cross-check both and suggest possible sources of error. Other groups and individuals have been setting up similar experiments to further the body of data available. This isn't some conspiracy where one individual or small group has a financial incentive to fool the world. Either usable thrust is being generated, or it isn't; one way or another we will know in time.

Precisely. It's not like these experiments have been hidden away from the public view.

As to the conservation of momentum question the number of times that gets asked and answered suggests that a FAQ is needed.

Offline john smith 19

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #170 on: 05/01/2015 06:37 AM »
Of course, your kinetic energy would be ridiculously high, thousands of times greater than the energy you put into the drive.

For .4N/kW and 40kg/kW specific power for a 1kW craft (weighing 40kg) just to make things easy:

(Kinetic Energy)/(Energy input)=
(.5*40kg*(92years*.4N/kW/(40kg/kW))^2)/(1kW*92years)
=
5806.5

Make no mistake, this is also a method to gain free energy.
Another useful meme is to beware of people who have simple answers to complex questions.

If Dr White's team is right this thruster is more akin to a propeller or the air breathing nuclear ramjet of project PLUTO, and the "reaction mass" are the virtual particles being preferentially accelerated by the system.

An interesting (but off topic) question would be does a virtual particle cease to exist entirely IE it's whole life is the single existence it's there for, or does it pop up "elsewhere," and is that "elsewhere" this universe, or another universe?

But let me ask you a simpler question.

Do you believe there is something there or IYHO it's all a set of experimental artifacts that have simply not been analyzed out thoroughly enough?
« Last Edit: 05/01/2015 06:40 AM by john smith 19 »
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Online sanman

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #171 on: 05/01/2015 06:46 AM »
An interesting (but off topic) question would be does a virtual particle cease to exist entirely IE it's whole life is the single existence it's there for, or does it pop up "elsewhere," and is that "elsewhere" this universe, or another universe?

LOL, maybe the EM drive allows you to propel objects in another universe   ;D

Offline ppnl

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #172 on: 05/01/2015 07:01 AM »
The thing to keep at the forefront of your mind is that decades after the first claim of cold fusion there are people still "generating data" and "doing experiments".  It seems like every few years there is a new wave of results. Tech dirt was hyping the latest just last year I think. Every few years Rossi produces a new E-cat that he shops around. Decades from now people will still be debating the EM-drive along with the E-cat. Desire produces suspension of disbelief. That suspension hides the monstrous improbability of the claims. You really are the easiest person for you to fool.

Paul March has been very forthcoming on NSF with experimental setup and data, allowing other experts to cross-check both and suggest possible sources of error. Other groups and individuals have been setting up similar experiments to further the body of data available. This isn't some conspiracy where one individual or small group has a financial incentive to fool the world. Either usable thrust is being generated, or it isn't; one way or another we will know in time.

And March of next year the debate will still be going on. And the march after. This is so exactly like the early days of Pons  and Fleischmann. Either excess heat is being generated, or it isn't; one way or another we will know in time. Yet 26 years later they are still having conferences.

It isn't about conspiracy or con men. It is about self deception and the desire to believe.

Offline CW

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #173 on: 05/01/2015 07:02 AM »
An interesting (but off topic) question would be does a virtual particle cease to exist entirely IE it's whole life is the single existence it's there for, or does it pop up "elsewhere," and is that "elsewhere" this universe, or another universe?

LOL, maybe the EM drive allows you to propel objects in another universe   ;D

Yeah.. and maybe matter is actually an opening in higher-dimensional space that sucks virtual particle pairs into micro-wormholes (=gravity) and randomly spews them out again elsewhere, which we can then observe as an expansion of space. Riiight.. now back to data collection.
;)
« Last Edit: 05/01/2015 07:07 AM by CW »
Reality is weirder than fiction

Offline ppnl

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #174 on: 05/01/2015 07:23 AM »

The thing to keep at the forefront of your mind is that decades after the first claim of cold fusion there are people still "generating data" and "doing experiments".  It seems like every few years there is a new wave of results. Tech dirt was hyping the latest just last year I think. Every few years Rossi produces a new E-cat that he shops around. Decades from now people will still be debating the EM-drive along with the E-cat. Desire produces suspension of disbelief. That suspension hides the monstrous improbability of the claims. You really are the easiest person for you to fool.

Paul March has been very forthcoming on NSF with experimental setup and data, allowing other experts to cross-check both and suggest possible sources of error. Other groups and individuals have been setting up similar experiments to further the body of data available. This isn't some conspiracy where one individual or small group has a financial incentive to fool the world. Either usable thrust is being generated, or it isn't; one way or another we will know in time.

Precisely. It's not like these experiments have been hidden away from the public view.

As to the conservation of momentum question the number of times that gets asked and answered suggests that a FAQ is needed.

A FAQ will not change the fact that you are on the horns of a dilemma. Either the thing accelerates constantly and you violate energy and momentum or it does not and you create a preferred frame of reference. Which is it? 

Offline TheTraveller

A FAQ will not change the fact that you are on the horns of a dilemma. Either the thing accelerates constantly and you violate energy and momentum or it does not and you create a preferred frame of reference. Which is it?
According to Shawyer, when the EMDrive accelerates, the resonate cavity loses energy to the accelerating mass and it's Q drops, which reduces the generated force. To maintain constant force, the primary energy source needs to restore the lost resonate cavity energy. End result is COE is conserved.

When Shawyer builds a demonstrator EMDrive it is serious hardware: http://emdrive.com/demonstratorengine.html

No microNewtons here:

Quote
The engine was built with a design factor of 0.844 and has a measured Q of 45,000 for an overall diameter of 280 mm. The microwave source is a water cooled magnetron with a variable output power up to a maximum of 1.2 kW.

To obtain the predicted thrust the engine must maintain stable resonance at this high Q value. Major design challenges have included thermal compensation, tuning control and source matching.

The engine was tested in a large static test rig employing a calibrated composite balance to measure thrust in 3 directions, up, down and horizontal. A total of 134 test runs were carried out over the full performance envelope, with a maximum specific thrust of 214mN/kW being measured.

You could feel the 22 grams of thrust with your hand.

My question is why didn't EagleWorks test this unit as it appears to be almost fully self contained and travel ready?
« Last Edit: 05/01/2015 08:25 AM by TheTraveller »
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Offline ppnl

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #176 on: 05/01/2015 08:29 AM »
A FAQ will not change the fact that you are on the horns of a dilemma. Either the thing accelerates constantly and you violate energy and momentum or it does not and you create a preferred frame of reference. Which is it?
According to Shawyer, when the EMDrive accelerates, the resonate cavity loses energy to the accelerating mass and it's Q drops, which reduces the generated force. To maintain constant force, the primary energy source needs to restore the lost resonate cavity energy. End result is COE is conserved.

Yeah, see that isn't very clear. And at best it does not solve your problem. Worse, I can't even tell if you understand the problem.

Ok lets say you have a spaceship powered by the Em-drive. Say you are motionless in space and turn it on and a thousand watts of power gives you a tenth of a gravity of acceleration. You accelerate up to a mile per second. Ok now how many watts of power does it take to continue accelerating at a tenth of a gravity? The same thousand? A million watts? more?

If it is the same thousand watts then you are violating conservation of energy. Do you understand this?

If you need more power at higher velocity then you can tell your absolute velocity by how much energy your engine needs to accelerate. This effectively creates a preferred frame of reference in violation of just about all modern physics. Do you understand this?

Offline TheTraveller

A FAQ will not change the fact that you are on the horns of a dilemma. Either the thing accelerates constantly and you violate energy and momentum or it does not and you create a preferred frame of reference. Which is it?
According to Shawyer, when the EMDrive accelerates, the resonate cavity loses energy to the accelerating mass and it's Q drops, which reduces the generated force. To maintain constant force, the primary energy source needs to restore the lost resonate cavity energy. End result is COE is conserved.

Yeah, see that isn't very clear. And at best it does not solve your problem. Worse, I can't even tell if you understand the problem.

Ok lets say you have a spaceship powered by the Em-drive. Say you are motionless in space and turn it on and a thousand watts of power gives you a tenth of a gravity of acceleration. You accelerate up to a mile per second. Ok now how many watts of power does it take to continue accelerating at a tenth of a gravity? The same thousand? A million watts? more?

If it is the same thousand watts then you are violating conservation of energy. Do you understand this?

If you need more power at higher velocity then you can tell your absolute velocity by how much energy your engine needs to accelerate. This effectively creates a preferred frame of reference in violation of just about all modern physics. Do you understand this?
EMDrive creates force from microwave energy input. To do work, accelerate the ship's mass, the EMDrive acts like a conversion conduit, converting source electrical energy into microwave energy, stored in the resonate cavity, into kinetic energy gain as the ship accelerates.

COE is conserved.

At one time it was not known an electrical current, flowing in a coil, could produce a magnetic field, that produced force on nearby ferrous objects. However for the magnetic field to do work on the ferrous objects / move them, that energy came from the primary electrical energy source and not from the coil's magnetic force field.

Different dog, same leg action.
« Last Edit: 05/01/2015 08:49 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
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Offline ppnl

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Re: FEATURE ARTICLE: Evaluating NASA's Futuristic EM Drive
« Reply #178 on: 05/01/2015 09:11 AM »
A FAQ will not change the fact that you are on the horns of a dilemma. Either the thing accelerates constantly and you violate energy and momentum or it does not and you create a preferred frame of reference. Which is it?
According to Shawyer, when the EMDrive accelerates, the resonate cavity loses energy to the accelerating mass and it's Q drops, which reduces the generated force. To maintain constant force, the primary energy source needs to restore the lost resonate cavity energy. End result is COE is conserved.

Yeah, see that isn't very clear. And at best it does not solve your problem. Worse, I can't even tell if you understand the problem.

Ok lets say you have a spaceship powered by the Em-drive. Say you are motionless in space and turn it on and a thousand watts of power gives you a tenth of a gravity of acceleration. You accelerate up to a mile per second. Ok now how many watts of power does it take to continue accelerating at a tenth of a gravity? The same thousand? A million watts? more?

If it is the same thousand watts then you are violating conservation of energy. Do you understand this?

If you need more power at higher velocity then you can tell your absolute velocity by how much energy your engine needs to accelerate. This effectively creates a preferred frame of reference in violation of just about all modern physics. Do you understand this?
EMDrive creates force from microwave energy input. To do work, accelerate the ship's mass, the EMDrive acts like a conversion conduit, converting source electrical energy into microwave energy, stored in the resonate cavity, into kinetic energy gain as the ship accelerates.

COE is conserved.

At one time it was not known an electrical current, flowing in a coil, could produce a magnetic field, that produced force on nearby ferrous objects. However for the magnetic field to do work on the ferrous objects / move them, that energy came from the primary electrical energy source and not from the coil's magnetic force field.

Different dog, same leg action.

Yeah, even less clear. your failure to answer my question leaves me no choice but to assume that you don't understand the problem. You simply assert COE and never even mention the problem with a preferred frame of reference. If you will not answer my question I don't know how to proceed but I'm pretty sure A FAQ isn't going to help. But feel free to go tell your friends that the COE question has been asked and answered countless times and I'll tell people how pointless it is to play chess with a pigeon.

Or you can try to understand and answer the questions I asked.


 

Offline TheTraveller

A FAQ will not change the fact that you are on the horns of a dilemma. Either the thing accelerates constantly and you violate energy and momentum or it does not and you create a preferred frame of reference. Which is it?
Force is not Work.

Shawyer clearly states when the cavity moves, it's Q drops, which means it's load impedance as seen by the microwave generator on board the ship drops. This causes the microwave generator to deliver more energy into the resonate cavity to restore the lost cavity energy (due to lower cavity Q due to cavity energy converted into Kinetic energy by the EMDrive) from the electrical source

No where does Shawyer claim the EMDrive will constantly accelerate, as you assume, without needing more microwave energy to be inputted into the resonate cavity.

If you would like to review what Shawyer has said, please read all the papers and links here: www.emdrive.com

See his theory paper and equations for power needed to support EMDrive acceleration:
http://www.emdrive.com/theorypaper9-4.pdf
« Last Edit: 05/01/2015 09:34 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

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