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General Discussion => New Physics for Space Technology => Topic started by: Star One on 10/11/2019 04:04 pm

Title: Helical Engine
Post by: Star One on 10/11/2019 04:04 pm
Sounds hugely inefficient at the very least.

https://www.newscientist.com/article/2218685-nasa-engineers-helical-engine-may-violate-the-laws-of-physics/
Title: Re: Helical Engine
Post by: meberbs on 10/12/2019 12:38 am
It was also linked on the emDrive thread, but to keep things clean, better to use this new thread.
Something like Woodward and his team envisions but with a little twist.

Quote
Burns, David   (NASA Marshall Space Flight Center, Huntsville, AL, United States)
Abstract:   A new concept for in-space propulsion is proposed in which propellant is not ejected from the engine, but instead is captured to create a nearly infinite specific impulse. The engine accelerates ions confined in a loop to moderate relativistic speeds, and then varies their velocity to make slight changes to their mass. The engine then moves ions back and forth along the direction of travel to produce thrust. This in-space engine could be used for long-term satellite station-keeping without refueling. It could also propel spacecraft across interstellar distances, reaching close to the speed of light. The engine has no moving parts other than ions traveling in a vacuum line, trapped inside electric and magnetic fields.
Publication Date:   August 19, 2019
https://ntrs.nasa.gov/search.jsp?R=20190029657
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029657.pdf

Shell

I am not sure exactly what they are claiming, but I think I worked out the source of the confusion.

At first I expected that this would be something that works by radiating photons, or maybe something with "hidden momentum" in electrodynamics. After looking at it closer I think there is just a simple misunderstanding of relativity. They state that since F = m*a, the z velocity would not change from a force in the x or y directions. That is simply wrong, because the better definition is F = dp/dt where p=momentum. For an object with velocity in the x and z directions, applying a force in the x direction increases the energy of the particle, increasing its relativistic mass. This therefore means the velocity of the particle in the z direction would decrease proportional to the additional mass to keep the z component of momentum constant. Basically this boils down to confusion about what happens in relativity when applying forces at angles, and they simply don't actually do the detailed calculations to point to a clear location for their mistake.

A classical analogy is if you drop a sack of flower onto the bed of a moving truck (ignore friction with the road etc.). The truck slows down despite there being no external force that you apply. That it because there is a force between the the sack and the truck as the sack starts at 0 velocity and friction with the truck causes it to accelerate. to match the truck velocity while the truck slows an equivalent amount. The extra relativistic mass is basically equivalent, having come from the source of the external force (not from nowhere) and initially not coming with any z momentum, so it needs to catch up by slowing the rest of the particle mass slightly in the z direction.

The presentation helpfully ends with the following, which is much preferable to the common absolute assertions that "this must work" often seen in propellantless propulsion papers.
Quote
•Basic concept is unproven
•Has not been reviewed by subject matter experts
•Math errors may exist!
Title: Re: Helical Engine
Post by: Star One on 10/12/2019 06:32 am
I started a new thread as my interpretation of what was said in the article I posted was that he didn’t want it associated with something like the EM drive.
Title: Re: Helical Engine
Post by: Bob012345 on 10/13/2019 09:55 pm
Quote
•Basic concept is unproven
•Has not been reviewed by subject matter experts
•Math errors may exist!

I think this whole paper just amounts to "Hey, here's a neat idea that probably won't work but I thought of it first."
Title: Re: Helical Engine
Post by: bad_astra on 10/14/2019 06:52 am
Quote
•Basic concept is unproven
•Has not been reviewed by subject matter experts
•Math errors may exist!

I think this whole paper just amounts to "Hey, here's a neat idea that probably won't work but I thought of it first."

It reads in places like a potus Tweet

"Basic concept is unproven•Has not been reviewed by subject matter experts•Math errors may exist!"

Yep, that's what you want to see in a public NASA paper written by the deputy of Space Systems Department, MSFC.
I wake up every morning lately wondering of it's April 1, but is it April 1?
Title: Re: Helical Engine
Post by: Cererean on 10/14/2019 11:10 am
Has he accounted for the mass of the energy?

If you have a self contained accelerator/decelerator system, the ions gain mass as they speed up and lose it as they slow down. But the energy to do that has to be stored in the system as well, so you're alternating between kinetic and other forms of it. Since the energy has mass of its own, which will be substantial, the overall system doesn't change its mass, so moving it back and forth doesn't generate a net thrust.
Title: Re: Helical Engine
Post by: mlorrey on 10/14/2019 07:08 pm
This is just Burns trying to coopt Woodward's Mach Effect theory and his thruster tech, and apply his own  theory to it so he can slap his name on it.
Title: Re: Helical Engine
Post by: meberbs on 10/14/2019 07:18 pm
This is just Burns trying to coopt Woodward's Mach Effect theory and his thruster tech, and apply his own  theory to it so he can slap his name on it.
No, this has literally nothing to do with Mach effects.

Also, you just finished telling people off in the other thread for daring to refer to it as Woodward's effect, and now you do so yourself, giving the possession to him. (Which isn't actually wrong, the issue is you giving him the possession right after you incorrectly claimed that was a tool to dismiss him.)
Title: Re: Helical Engine
Post by: AnalogMan on 10/14/2019 07:20 pm
There is a conference paper that accompanies the presentation slides linked to in the second post.  May give more details for those who are interested.

Links:
https://ntrs.nasa.gov/search.jsp?R=20190029294 (https://ntrs.nasa.gov/search.jsp?R=20190029294)
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029294.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029294.pdf)
Title: Re: Helical Engine
Post by: meberbs on 10/14/2019 07:51 pm
There is a conference paper that accompanies the presentation slides linked to in the second post.  May give more details for those who are interested.

Links:
https://ntrs.nasa.gov/search.jsp?R=20190029294 (https://ntrs.nasa.gov/search.jsp?R=20190029294)
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029294.pdf (https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029294.pdf)
Looking through this confirms my initial thoughts. They are ignoring the fact that no force in the z-axis means constant z component of momentum, not constant z component of velocity. They also seem to miss the fact that a force tangential to the circle with no z component would have both parallel and perpendicular components (relative to particle velocity) which are related to acceleration by different equations as they show. If they worked through the math on those equations, the result would change the z component of velocity at exactly the rate needed to keep the z component of momentum constant.
Title: Re: Helical Engine
Post by: mlorrey on 10/14/2019 11:53 pm
This is just Burns trying to coopt Woodward's Mach Effect theory and his thruster tech, and apply his own  theory to it so he can slap his name on it.
No, this has literally nothing to do with Mach effects.

Also, you just finished telling people off in the other thread for daring to refer to it as Woodward's effect, and now you do so yourself, giving the possession to him. (Which isn't actually wrong, the issue is you giving him the possession right after you incorrectly claimed that was a tool to dismiss him.)
Woodward deserves credit for the theoretical work and experimental work, and as the discoverer, he has the right to name the effect. Burns has his own theory to claim inertial manipulation via transient mass variations. This sort of cooption is  not new. Sonny White tried to do the same thing several years ago, while in possession of a Mach Effect Thruster made for him  by  Woodward.
Title: Re: Helical Engine
Post by: leovinus on 10/15/2019 11:12 pm
https://arstechnica.com/science/2019/10/corkscrewing-bouncy-ion-drive-would-provide-thrust-in-different-universe/
Title: Re: Helical Engine
Post by: Ixokani on 10/16/2019 12:38 pm
I like the analogy in one of the comments on that ARS article:

https://arstechnica.com/science/2019/10/corkscrewing-bouncy-ion-drive-would-provide-thrust-in-different-universe/?comments=1&post=38115607#comment-38115607 (https://arstechnica.com/science/2019/10/corkscrewing-bouncy-ion-drive-would-provide-thrust-in-different-universe/?comments=1&post=38115607#comment-38115607)

Quote
It sounds like the equivalent of taking your car out of gear, sitting in the back seat and trying to get it to move forward by throwing a tennis ball (at relativistic velocities) at the dashboard.
Title: Re: Helical Engine
Post by: ChrisWilson68 on 10/16/2019 05:52 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.
Title: Re: Helical Engine
Post by: trm14 on 10/16/2019 07:38 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.

It's really strange and frustrating how many seem to think that some sort of clever contraption can do something that can be proven to be impossible within known laws of physics. Yet they claim that no new physics is needed. Though I guess I shouldn't be surprised, impossibility of angle trisection (under the classical rules) has been known for more than 150 years, but plenty of people are still trying.

There's appears to be an odd divide in people's minds between conservation of energy on one hand and conservation of momentum on the other.  I seems to me that people are much more willing to accept propellantless drives than perpetual motion machines, as if conservation of energy were somehow a more sacred law of nature.
Title: Re: Helical Engine
Post by: edzieba on 10/17/2019 12:49 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.

It's really strange and frustrating how many seem to think that some sort of clever contraption can do something that can be proven to be impossible within known laws of physics. Yet they claim that no new physics is needed. Though I guess I shouldn't be surprised, impossibility of angle trisection (under the classical rules) has been known for more than 150 years, but plenty of people are still trying.

There's appears to be an odd divide in people's minds between conservation of energy on one hand and conservation of momentum on the other.  I seems to me that people are much more willing to accept propellantless drives than perpetual motion machines, as if conservation of energy were somehow a more sacred law of nature.
To play Devils Advocate:
A close approximation of a reactionless drive is useful even if it not a 'real' reactionless drive. A perfect angle trisector may be impossible, but a 6-sigma approximation is still useful for the cases where you need to draw an angle geometrically. Likewise, your drive may not be a 'true' reactionless drive and may 'merely' be just pushing against distant masses/vacuum potential/dark energy/all of the universe/the luminiferous aether, but if it takes in energy and gains momentum with more efficiency than a photon rocket, then it has utility.

The problem of course is that so far no drive has even met the low bar of demonstrating the same efficiency as a photon rocket (or indeed working period).
Title: Re: Helical Engine
Post by: Star One on 10/17/2019 01:35 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.

Yet the person proposing this is hardly some nobody from the streets. So I would guess he’s more qualified than you or I in this area.
Title: Re: Helical Engine
Post by: trm14 on 10/17/2019 03:19 pm
To play Devils Advocate:
A close approximation of a reactionless drive is useful even if it not a 'real' reactionless drive. A perfect angle trisector may be impossible, but a 6-sigma approximation is still useful for the cases where you need to draw an angle geometrically. Likewise, your drive may not be a 'true' reactionless drive and may 'merely' be just pushing against distant masses/vacuum potential/dark energy/all of the universe/the luminiferous aether, but if it takes in energy and gains momentum with more efficiency than a photon rocket, then it has utility.

But all of those would mean new physics (at least according to how most physicist see it), while many claim to get propellantless propulsion from well established theories like Maxwell's equations or special relativity. 

Sure, there are also some theories that do propose new physics, although none have been particularly convincing. But at least the proposers recognise that something new is needed.

(Constructing a perfect trisector of an angle is possible and at least one method was known to ancient Greeks. But it isn't a compass and (unmarked) straightedge construction.)
Title: Re: Helical Engine
Post by: meberbs on 10/17/2019 03:20 pm
To play Devils Advocate:
A close approximation of a reactionless drive is useful even if it not a 'real' reactionless drive. A perfect angle trisector may be impossible, but a 6-sigma approximation is still useful for the cases where you need to draw an angle geometrically. Likewise, your drive may not be a 'true' reactionless drive and may 'merely' be just pushing against distant masses/vacuum potential/dark energy/all of the universe/the luminiferous aether, but if it takes in energy and gains momentum with more efficiency than a photon rocket, then it has utility.
No, you are stretching the analogy to where it doesn't apply. A close approximation of a reactionless drive is still a device that sits there and does nothing. All of those things that you listed about how the drive actually pushes off something: those are not possible within standard physics. They all require something new or magical to appear to make them work. The whole point is that many concepts such as the one in this thread, or Shawyer's claims about the emDrive are claimed to work without any of that. Since they are based purely on existing physics, it is 100% guaranteed that the result is due to a maathematical error by the person proposing it.

Yet the person proposing this is hardly some nobody from the streets. So I would guess he’s more qualified than you or I in this area.
No he literally says that he is not a subject matter expert when he says that the proposal has not been reviewed by a subject matter expert and may contain errors. There is no reason to think he is more qualified than any other random person, and is certainly less qualified than anyone who knows that special relativity is proven consistent and that such ideas simply do not work in it. To his credit he at least acknowledged that he may be wrong unlike roughly 90% of such impossible proposals.
Title: Re: Helical Engine
Post by: Bob012345 on 10/17/2019 04:15 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.

It's really strange and frustrating how many seem to think that some sort of clever contraption can do something that can be proven to be impossible within known laws of physics. Yet they claim that no new physics is needed. Though I guess I shouldn't be surprised, impossibility of angle trisection (under the classical rules) has been known for more than 150 years, but plenty of people are still trying.

There's appears to be an odd divide in people's minds between conservation of energy on one hand and conservation of momentum on the other.  I seems to me that people are much more willing to accept propellantless drives than perpetual motion machines, as if conservation of energy were somehow a more sacred law of nature.

The idea that we know enough to discount any conceivable possibility that the laws of physics as we know them might have some practical "loopholes" at least at a local level yet to be discovered is the more problematic stance. For example, can one say apriori that it wouldn't be worth it to even consider the existence of such things as Mach effect devices? Especially when we do admit in physics violations of energy conservation at the quantum level, entanglement over the size of the universe, multiple universes just springing into existence which seemingly also violate conservation of energy. The problem is that the proof that something is impossible often assumes only what's known at present and disallows not necessarily new physics, though that may be needed, but new understandings of established physics. In 1957 Yang and Lee won a Nobel prize for overthrowing the Conservation of Parity, something so basic to physicists it was as shocking as overthrowing conservation of momentum would be. Then there's concepts such as the Alcubierre Drive which though may never be, probably won't be practical, at least in principle allowed the possibility to overcome the speed of light. Shocking indeed. Perhaps the reviewers should have just told Alcubierre that his idea used "bad math" and violated Special Relativity and prevented publication! That seems simple, enough on the surface. I'm glad they didn't so the idea could be explored.

BTW, true propellentless propulsion devices would also be energy generation devices. Just spin up the device in a rotating reference frame with constant power giving constant acceleration and harvest the kinetic energy in a non-rotating frame where the kinetic energy rises as time squared. Of course that cuts two ways as it could also be used as an argument such a device is impossible.
Title: Re: Helical Engine
Post by: ChrisWilson68 on 10/17/2019 04:43 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.

It's really strange and frustrating how many seem to think that some sort of clever contraption can do something that can be proven to be impossible within known laws of physics. Yet they claim that no new physics is needed. Though I guess I shouldn't be surprised, impossibility of angle trisection (under the classical rules) has been known for more than 150 years, but plenty of people are still trying.

There's appears to be an odd divide in people's minds between conservation of energy on one hand and conservation of momentum on the other.  I seems to me that people are much more willing to accept propellantless drives than perpetual motion machines, as if conservation of energy were somehow a more sacred law of nature.

The idea that we know enough to discount any conceivable possibility that the laws of physics as we know them might have some practical "loopholes" at least at a local level yet to be discovered is the more problematic stance.

You are incorrect.

You are confusing things that are really new physics with what Helical Engine idea supposes: new consequences of conventional physics that violate rules that have been mathematically proven to follow from the rules of conventional physics.

The idea of a loophole may be appealing intuitively, but math doesn't allow for loopholes.

For example, can one say apriori that it wouldn't be worth it to even consider the existence of such things as Mach effect devices?

The Mach effect does not follow from conventional physics.  It is a new physics idea.

Especially when we do admit in physics violations of energy conservation at the quantum level,

Any sort of violation of conservation of energy at the quantum level is by necessity below the observable threshold.  If it can be observed, it can't happen.  In other words, it's not possible for there to be violation of conservation of energy in a way that can have a measurable effect.  Violation of conservation of energy in quantum mechanics is really more like fuzziness of boundaries rather than true violation.

entanglement over the size of the universe, multiple universes just springing into existence which seemingly also violate conservation of energy.

If there is a violation of conservation of energy, it needs new physics to explain it, because conventionally accepted physics does not allow it.

The problem is that the proof that something is impossible often assumes only what's known at present and disallows not necessarily new physics, though that may be needed, but new understandings of established physics.

That is incorrect.  A new understanding of established physics won't do it.  That's what a mathematical proof means.  No "new understanding" can get you around a mathematical proof.

The square root of 2 is irrational.  No new understanding of math will give you a finite fraction equal to the square root of 2.

In 1957 Yang and Lee won a Nobel prize for overthrowing the conservation of Parity, something so basic to physicists it was as shocking as overthrowing conservation of momentum would be.

And that was new physics at the time.

Nobody is saying there can't be new physics.  What we are saying is that new physics is necessary for a reactionless drive.

Then there's concepts such as the Alcubierre Drive which though may never be, probably won't be practical, at least in principle allowed the possibility to overcome the speed of light.

You are incorrect.  The Alcubierre Drive doesn't allow overcoming the speed of light without new physics.  It has been proven (mathematical proof, again) that you can't set an Alcubierre Drive in motion unless you already have a faster-than-light drive.  It also requires negative mass, which is also new physics.

Shocking indeed. Perhaps the reviewers should have just told Alcubierre that his idea used "bad math" and violated Special Relativity and prevented publication! That seems simple, enough on the surface. I'm glad they didn't so the idea could be explored.

The Alcubierre drive isn't what you think it is.  It doesn't violate any mathematically proven properties of conventional physics without adding new physics.

BTW, true propellentless propulsion devices would also be energy generation devices. Just spin up the device in a rotating reference frame with constant power giving constant acceleration and harvest the kinetic energy in a non-rotating frame where the kinetic energy rises as time squared. Of course that cuts two ways as it could also be used as an argument such a device is impossible.

You're not helping your case with these statements.
Title: Re: Helical Engine
Post by: meberbs on 10/17/2019 04:50 pm
Chris Wilson beat me to saying the exact same things (and said it better), but I already wrote this, so here it is:
The idea that we know enough to discount any conceivable possibility that the laws of physics as we know them might have some practical "loopholes" at least at a local level yet to be discovered is the more problematic stance.
No, it is called mathematics and rigorous proofs.

For example, can one say apriori that it wouldn't be worth it to even consider the existence of such things as Mach effect devices?
Such devices only maybe work when applying New Physics, since Mach's principle (at least the relevant version) is not part of GR.

Especially when we do admit in physics violations of energy conservation at the quantum level, entanglement over the size of the universe, multiple universes just springing into existence which seemingly also violate conservation of energy.
No, there are no violations of conservation of energy at the quantum level. Claims of that are misunderstandings. You successfully point out one of the major issues with the many worlds interpretation of quantum mechanics. There is nothing in the theory that requires that that interpretation is correct.

The problem is that the proof that something is impossible often assumes only what's known at present and disallows not necessarily new physics, though that may be needed, but new understandings of established physics.
No, not true.

In 1957 Yang and Lee won a Nobel prize for overthrowing the Conservation of Parity, something so basic to physicists it was as shocking as overthrowing conservation of momentum would be.
That is what is known as new physics.

Then there's concepts such as the Alcubierre Drive which though may never be, probably won't be practical, at least in principle allowed the possibility to overcome the speed of light. Shocking indeed. Perhaps the reviewers should have just told Alcubierre that his idea used "bad math" and violated Special Relativity and prevented publication! That seems simple, enough on the surface. I'm glad they didn't so the idea could be explored.
The Alcubierrre drive relies on negative mass, which is .... new physics.

BTW, true propellentless propulsion devices would also be energy generation devices. Just spin up the device in a rotating reference frame with constant power giving constant acceleration and harvest the kinetic energy in a non-rotating frame where the kinetic energy rises as time squared. Of course that cuts two ways as it could also be used as an argument such a device is impossible.
Yep, that much is correct, and tends to get downplayed by people who propose propellantless propulsion schemes, probably related to what trm14 mentioned about how people seem more willing to throw out conservation of momentum (even in physics laws known to inherently conserve momentum), but not conservation of energy.
Title: Re: Helical Engine
Post by: Bob012345 on 10/17/2019 05:59 pm
Like a lot of threads in this section, this isn't so much a "New Physics" idea.  It's more a "Conventional Physics Claimed to Do Something Mathematically Proven Impossible with Conventional Physics" idea.  Or, perhaps more succinctly, "Bad Math with Conventional Physics".

Maybe we need a new section.

It's really strange and frustrating how many seem to think that some sort of clever contraption can do something that can be proven to be impossible within known laws of physics. Yet they claim that no new physics is needed. Though I guess I shouldn't be surprised, impossibility of angle trisection (under the classical rules) has been known for more than 150 years, but plenty of people are still trying.

There's appears to be an odd divide in people's minds between conservation of energy on one hand and conservation of momentum on the other.  I seems to me that people are much more willing to accept propellantless drives than perpetual motion machines, as if conservation of energy were somehow a more sacred law of nature.

The idea that we know enough to discount any conceivable possibility that the laws of physics as we know them might have some practical "loopholes" at least at a local level yet to be discovered is the more problematic stance.

You are incorrect.

You are confusing things that are really new physics with what Helical Engine idea supposes: new consequences of conventional physics that violate rules that have been mathematically proven to follow from the rules of conventional physics.

The idea of a loophole may be appealing intuitively, but math doesn't allow for loopholes.

For example, can one say apriori that it wouldn't be worth it to even consider the existence of such things as Mach effect devices?

The Mach effect does not follow from conventional physics.  It is a new physics idea.

Especially when we do admit in physics violations of energy conservation at the quantum level,

Any sort of violation of conservation of energy at the quantum level is by necessity below the observable threshold.  If it can be observed, it can't happen.  In other words, it's not possible for there to be violation of conservation of energy in a way that can have a measurable effect.  Violation of conservation of energy in quantum mechanics is really more like fuzziness of boundaries rather than true violation.

entanglement over the size of the universe, multiple universes just springing into existence which seemingly also violate conservation of energy.

If there is a violation of conservation of energy, it needs new physics to explain it, because conventionally accepted physics does not allow it.

The problem is that the proof that something is impossible often assumes only what's known at present and disallows not necessarily new physics, though that may be needed, but new understandings of established physics.

That is incorrect.  A new understanding of established physics won't do it.  That's what a mathematical proof means.  No "new understanding" can get you around a mathematical proof.

The square root of 2 is irrational.  No new understanding of math will give you a finite fraction equal to the square root of 2.

In 1957 Yang and Lee won a Nobel prize for overthrowing the conservation of Parity, something so basic to physicists it was as shocking as overthrowing conservation of momentum would be.

And that was new physics at the time.

Nobody is saying there can't be new physics.  What we are saying is that new physics is necessary for a reactionless drive.

Then there's concepts such as the Alcubierre Drive which though may never be, probably won't be practical, at least in principle allowed the possibility to overcome the speed of light.

You are incorrect.  The Alcubierre Drive doesn't allow overcoming the speed of light without new physics.  It has been proven (mathematical proof, again) that you can't set an Alcubierre Drive in motion unless you already have a faster-than-light drive.  It also requires negative mass, which is also new physics.

Shocking indeed. Perhaps the reviewers should have just told Alcubierre that his idea used "bad math" and violated Special Relativity and prevented publication! That seems simple, enough on the surface. I'm glad they didn't so the idea could be explored.

The Alcubierre drive isn't what you think it is.  It doesn't violate any mathematically proven properties of conventional physics without adding new physics.

BTW, true propellentless propulsion devices would also be energy generation devices. Just spin up the device in a rotating reference frame with constant power giving constant acceleration and harvest the kinetic energy in a non-rotating frame where the kinetic energy rises as time squared. Of course that cuts two ways as it could also be used as an argument such a device is impossible.

You're not helping your case with these statements.

First, thanks for your response!

I'm not exactly sure what 'case' you think I am making?

I can see where you might think I was using these examples to argue we should be open minded about the Helical Engine but that wasn't my point. I've already made my comment on that. My point was a comment on Trm14's sense of frustration that people propose such ideas in the first place and not to enter a semantic debate on whether such ideas are always about new physics or about new interpretations of existing physics. My post was not at all meant to defend the Helical Engine, it was just a general statement just about being open minded. It seems most of your response is arguing about whether to call it new physics or not. * I really don't care what we call it. I think one can argue that a new understanding of a solution in GR such as the  Alcubierre drive concept isn't actually new physics, it's a newly discovered solution of standard GR and not to a modified different theory so I respectfully disagree. A close "relative" of negative mass exists with the Casimir effect but negative mass was itself proposed by Hermann Bondi again in 1957. So that's not a recently invented concept. Woodward uses a previously existing theory by Hoyle and Narlikar again, not new.

So my comment "The idea that we know enough to discount any conceivable possibility that the laws of physics as we know them might have some practical "loopholes" at least at a local level yet to be discovered is the more problematic stance.".  is just a philosophical statement which people, are free to disagree with as I disagree with your statement " The idea of a loophole may be appealing intuitively, but math doesn't allow for loopholes." to which my response is that you simply can't know that because we don't know everything and math serves as a model for physics. If we don't know how the physics applies in all situations, we can't know what the math says in every (call it new if you want) situation.

*i edited out a comment I think was too judgmental (on my part) and this is a temporary comment in case your are still writing a response. Thanks again.
Title: Re: Helical Engine
Post by: Bob012345 on 10/17/2019 06:25 pm
BTW, true propellentless propulsion devices would also be energy generation devices. Just spin up the device in a rotating reference frame with constant power giving constant acceleration and harvest the kinetic energy in a non-rotating frame where the kinetic energy rises as time squared. Of course that cuts two ways as it could also be used as an argument such a device is impossible.
Yep, that much is correct, and tends to get downplayed by people who propose propellantless propulsion schemes, probably related to what trm14 mentioned about how people seem more willing to throw out conservation of momentum (even in physics laws known to inherently conserve momentum), but not conservation of energy.

Thanks. Most of my response to ChrisWilson68 is to your points as well but I want to add that I believe some folks are not trying to throw out COM but believe it is conserved in some global way such as Woodward et. al or make the case that EM field momentum can be larger than simple photon momentum and is conserved as Tuval and Yahalom make.
Title: Re: Helical Engine
Post by: meberbs on 10/17/2019 08:46 pm
It seems most of your response is arguing about whether to call it new physics or not. * I really don't care what we call it.
You are the one turning this into a semantic argument. Physics theories, GR, the standard Model, etc. are rigorously well defined. Something either uses them or it doesn't. Results that are proven not to work within them do not work in them. Claims of propellantless propulsion, including the one this thread is about, often explicitly say that they use only existing theories. This is already enough information to know that they don't work and aren't worth wasting time on.

The Alcubierre drive DOES NOT WORK in existing physics. It is a solution to a set of equations that are known to include non-physical results. It has since been shown that the Alcubierre drive is one of these.

The Casimir effect does not have any relationship to true negative mass, which is another proven fact.

Thanks. Most of my response to ChrisWilson68 is to your points as well but I want to add that I believe some folks are not trying to throw out COM but believe it is conserved in some global way such as Woodward et. al or make the case that EM field momentum can be larger than simple photon momentum and is conserved as Tuval and Yahalom make.
The Hoyle-Narlikar theory used by Woodward is not GR, but a modification of it. It does not matter when it was invented. (It does matter that Rodal published a paper showing that when the math is done correctly, the claimed effect doesn't work in that theory either.)

The equations of electromagnetism completely exclude magical EM waves with a better energy/momentum ratio. Claims otherwise are either new physics or wrong.

You keep mixing in the "but what about this idea that was proposed as an addition to physics" which simply is not the same thing as what trm14 expressed frustration with (and again this thread is an example of) where absolutely no proposed addition to physics is provided for a purely theoretical claim, known to be impossible within the theories that were used.

On a related note, there is a good Forbes article (https://www.forbes.com/sites/startswithabang/2019/10/17/for-the-last-time-no-a-nasa-engineer-has-not-broken-physics-with-an-impossible-engine/#7ce6ea3d27bf) today explaining exactly why the helical engine this thread is about does not work.
Title: Re: Helical Engine
Post by: Star One on 10/18/2019 01:58 pm
I have to laugh at someone using Forbes to make a counter argument. Especially as seemingly any old character can post anything on that site which as the top contributor says here was a bonkers decision.

https://www.quora.com/Is-Forbes-com-considered-a-credible-source-of-journalism-by-the-industry-in-light-of-its-use-of-contributors-and-incidents-like-calling-the-President-of-Ireland-a-“homosexual”
Title: Re: Helical Engine
Post by: meberbs on 10/18/2019 02:18 pm
I have to laugh at someone using Forbes to make a counter argument. Especially as seemingly any old character can post anything on that site which as the top contributor says here was a bonkers decision.

https://www.quora.com/Is-Forbes-com-considered-a-credible-source-of-journalism-by-the-industry-in-light-of-its-use-of-contributors-and-incidents-like-calling-the-President-of-Ireland-a-“homosexual”
Try reading the article and also looking at the qualifications of the author. This article is way better than what 90% of the media wrote on this subject. Other articles on that site can be terrrible, and I've seen bad ones, but that has no effect on the contents of this article.

It is rather ironic that you discredit it by pointing to a quora comment of all things, which also can be written by anyone. The comment also kills your own point by saying "Whether it's still credible depends on the author."
Title: Re: Helical Engine
Post by: Star One on 10/18/2019 03:16 pm
I have to laugh at someone using Forbes to make a counter argument. Especially as seemingly any old character can post anything on that site which as the top contributor says here was a bonkers decision.

https://www.quora.com/Is-Forbes-com-considered-a-credible-source-of-journalism-by-the-industry-in-light-of-its-use-of-contributors-and-incidents-like-calling-the-President-of-Ireland-a-“homosexual”
Try reading the article and also looking at the qualifications of the author. This article is way better than what 90% of the media wrote on this subject. Other articles on that site can be terrrible, and I've seen bad ones, but that has no effect on the contents of this article.

It is rather ironic that you discredit it by pointing to a quora comment of all things, which also can be written by anyone. The comment also kills your own point by saying "Whether it's still credible depends on the author."

Quora has more credibility than Forbes. It’s not difficult to find an article from a far more credible source in fact it’s the top hit on Google.

https://arstechnica.com/science/2019/10/corkscrewing-bouncy-ion-drive-would-provide-thrust-in-different-universe/
Title: Re: Helical Engine
Post by: meberbs on 10/18/2019 04:43 pm
I have to laugh at someone using Forbes to make a counter argument. Especially as seemingly any old character can post anything on that site which as the top contributor says here was a bonkers decision.

https://www.quora.com/Is-Forbes-com-considered-a-credible-source-of-journalism-by-the-industry-in-light-of-its-use-of-contributors-and-incidents-like-calling-the-President-of-Ireland-a-“homosexual”
Try reading the article and also looking at the qualifications of the author. This article is way better than what 90% of the media wrote on this subject. Other articles on that site can be terrrible, and I've seen bad ones, but that has no effect on the contents of this article.

It is rather ironic that you discredit it by pointing to a quora comment of all things, which also can be written by anyone. The comment also kills your own point by saying "Whether it's still credible depends on the author."

Quora has more credibility than Forbes. It’s not difficult to find an article from a far more credible source in fact it’s the top hit on Google.

https://arstechnica.com/science/2019/10/corkscrewing-bouncy-ion-drive-would-provide-thrust-in-different-universe/
For either source you have to look at the individual contribution to judge the credibility. The article you just linked has already been posted in this thread. The one on Forbes I feel does a bit better job explaining why the device in question wouldn't work, but it also has useful general insights. If you have nothing to say about the content of the articles, then this discussion simply is off topic.
Title: Re: Helical Engine
Post by: Bob012345 on 10/18/2019 05:31 pm
It seems most of your response is arguing about whether to call it new physics or not. * I really don't care what we call it.
You are the one turning this into a semantic argument. Physics theories, GR, the standard Model, etc. are rigorously well defined. Something either uses them or it doesn't. Results that are proven not to work within them do not work in them. Claims of propellantless propulsion, including the one this thread is about, often explicitly say that they use only existing theories. This is already enough information to know that they don't work and aren't worth wasting time on.

The Alcubierre drive DOES NOT WORK in existing physics. It is a solution to a set of equations that are known to include non-physical results. It has since been shown that the Alcubierre drive is one of these.

The Casimir effect does not have any relationship to true negative mass, which is another proven fact.

Thanks. Most of my response to ChrisWilson68 is to your points as well but I want to add that I believe some folks are not trying to throw out COM but believe it is conserved in some global way such as Woodward et. al or make the case that EM field momentum can be larger than simple photon momentum and is conserved as Tuval and Yahalom make.
The Hoyle-Narlikar theory used by Woodward is not GR, but a modification of it. It does not matter when it was invented. (It does matter that Rodal published a paper showing that when the math is done correctly, the claimed effect doesn't work in that theory either.)

The equations of electromagnetism completely exclude magical EM waves with a better energy/momentum ratio. Claims otherwise are either new physics or wrong.

You keep mixing in the "but what about this idea that was proposed as an addition to physics" which simply is not the same thing as what trm14 expressed frustration with (and again this thread is an example of) where absolutely no proposed addition to physics is provided for a purely theoretical claim, known to be impossible within the theories that were used.

On a related note, there is a good Forbes article (https://www.forbes.com/sites/startswithabang/2019/10/17/for-the-last-time-no-a-nasa-engineer-has-not-broken-physics-with-an-impossible-engine/#7ce6ea3d27bf) today explaining exactly why the helical engine this thread is about does not work.

I meant the word arguing as in making a case, not generating an argument. Thanks for the Forbes reference. It's an interesting article but I don't like the way Seigel pulls rank by commenting that Burns has a doctorate in Electrical Engineering rather than physics. Seigel also omits that Burns, unlike virtually every other dubious inventor, questions his own invention quite strongly suggesting the math may be wrong and that he doesn't fully understand the momentum issues. He doesn't tell us that Burns idea is really a proposal, that it's not clear it would work according to Burns himself and that Burns is actually proposing it so those questions could be answered. So rather than recognize that, Seigel chooses to ignore all that. All this to say of course Seigel is correct, the Helical Engine is fatally flawed. On that we fully and completely agree.
Title: Re: Helical Engine
Post by: meberbs on 10/18/2019 08:09 pm
I meant the word arguing as in making a case, not generating an argument. Thanks for the Forbes reference. It's an interesting article but I don't like the way Seigel pulls rank by commenting that Burns has a doctorate in Electrical Engineering rather than physics. Seigel also omits that Burns, unlike virtually every other dubious inventor, questions his own invention quite strongly suggesting the math may be wrong and that he doesn't fully understand the momentum issues. He doesn't tell us that Burns idea is really a proposal, that it's not clear it would work according to Burns himself and that Burns is actually proposing it so those questions could be answered. So rather than recognize that, Seigel chooses to ignore all that. All this to say of course Seigel is correct, the Helical Engine is fatally flawed. On that we fully and completely agree.
We are basically in agreement here, but I disagree with your comment about the author "pulling rank." Seigel just pointed out that the the fundamental mistake made by Burns is a common one. That includes among engineers, because special relativity has little direct application in engineering, especially when it comes to understanding how relativistic mass works. "Physicists" is the one major group among which this hopefully is not a common misunderstanding, because they would have reason to study it in more depth.

As you say (and I have already stated as well) Burns should be commended for acknowledging that his idea may be wrong (and Siegel does allude to this, because he quotes Burns saying "you have to be prepared to be embarrassed" when proposing such ideas.) I am not sure how this got from Burns to the media originally, but it would be better for things like this if there was review from the appropriate experts before a presentation like this getting to the media and creating dozens of "NASA breaks physics" headlines.
Title: Re: Helical Engine
Post by: Iggyz on 07/01/2022 05:25 pm
In this "What Da Math" video  https://www.youtube.com/watch?v=CKT5zlnw-MM (https://www.youtube.com/watch?v=CKT5zlnw-MM) Anton (about 4 min. 30 secs. into the video) says the helical shaped beam guide of the Helical Engine*  allows the bundle of ions to be accelerated and decelerated without generating a force that would propel the space ship in the opposite direction it is supposed to travel in.

Anton illustrates this at about 5 min. and 40 secs. into the video.

Can this work and wouldn't that be revolutionary?

If he is right, why not levitate and accelerate a mass of 1000 kg to e.g. 20 meters per second by a helical shaped linear motor fitted into a helical shaped vacuum cylinder, let the mass coast and bounce off the right end of the cylinder, pushing the space ship to the right.
 
Next, the returning mass is decelerated to a full stop (the space ship should continue move to the right) and accelerated again, restarting the cycle. Can this work?

The mass would develop 20.000 kg/s of momentum and less than one MW of energy would be needed for acceleration and deceleration. Less than 1% of the original Helical Engine energy consumption.

* Please see attached screenshot of fig. 4 on page 5 of the official Helical Engine paper (also attached).
Title: Re: Helical Engine
Post by: leovinus on 07/01/2022 05:31 pm
https://forum.nasaspaceflight.com/index.php?topic=49246.0

[zubenelgenubi: Threads merged.]
Title: Re: Helical Engine
Post by: Iggyz on 07/01/2022 05:45 pm
Thank you leovinus but none of the posts in that topic seem to answer the specific questions I am asking. Please clarify or link to the post that answers my questions.
Title: Re: Helical Engine
Post by: Nomadd on 07/01/2022 06:45 pm
Thank you leovinus but none of the posts in that topic seem to answer the specific questions I am asking. Please clarify or link to the post that answers my questions.
That link perfectly covers what you're asking. Trying to modify Daffy Duck physics to make them work better doesn't make them any more plausible.
Title: Re: Helical Engine
Post by: DanClemmensen on 07/01/2022 06:50 pm

Can this work and wouldn't that be revolutionary?

If he is right, why not levitate and accelerate a mass of 1000 kg to e.g. 20 meters per second by a helical shaped linear motor fitted into a helical shaped vacuum cylinder, let the mass coast and bounce off the right end of the cylinder, pushing the space ship to the right.
 
Next, the returning mass is decelerated to a full stop (the space ship should continue move to the right) and accelerated again, restarting the cycle. Can this work?

The mass would develop 20.000 kg/s of momentum and less than one MW of energy would be needed for acceleration and deceleration. Less than 1% of the original Helical Engine energy consumption.

No, no, no.   Please start by analyzing conservation of momentum. It is a fundamental law of physics. If anyone ever observes an actual, replicable violation of the law of conservation of momentum it will completely change all of physics.
Title: Re: Helical Engine
Post by: ppnl on 07/02/2022 02:46 am

https://www.forbes.com/sites/startswithabang/2019/10/17/for-the-last-time-no-a-nasa-engineer-has-not-broken-physics-with-an-impossible-engine/?sh=3a5bb5ea27bf