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The Helical Engine: Will It Work?

10/20/2019 10:03 PM

A NASA engineer has proposed an engine that requires no propellant to generate thrust, an apparent violation of the law of conservation of momentum. His idea is to move back and forth a ring of circulating ions along the z-axis. Normally moving a mass back and forth would result in no net thrust, but his idea is to change the mass of the ions by increasing and decreasing their tangential velocity in the x-y plane.

Per special relativity, the faster an object moves, the more massive it becomes. This is the Lorentz factor, γ, and is what keeps us from accelerating an object to light speed.

Lorentz factor γ as a function of velocity. Its initial value is 1 (when v = 0); and as velocity approaches the speed of light (vc) γ increases without bound (γ → ∞).

https://en.wikipedia.org/wiki/Lorentz_factor

Back and forth motion with mass change.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20190029657.pdf

https://www.youtube.com/watch?v=CKT5zlnw-MM

It's obviously not practical, but will it even work?

I'm thinking not, but not just cause I'm kind of fond of the Conservation of Momentum. I'm thinking there would be the same amount of momentum change in an ion as it transitioned through the cycle, so there would be no net thrust.

What do you think?

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#1

Re: The Helical Engine: will it work?

10/20/2019 11:41 PM

I think it would be easier to just wait for a large interstellar meteor to pass through our solar system, and hitch a ride using the material of the meteorite for whatever needs a robot might have, I don't see mankind leaving this solar system anytime in the foreseeable future, and maybe never...but that would require a faster than light communication system to really be of any value...It's certainly not out of the question that somebody someday might discover a means of propulsion that could sustain itself, but even traveling near light speed, any place we might go would still take a lifetime or more...

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#2
In reply to #1

Re: The Helical Engine: will it work?

10/21/2019 2:31 AM

Mankind will likely leave the solar system with 250 years.

It won't be conscious adults piloting a ship early on (or perhaps ever).

Embryos are much easier to keep in viable stasis than adults. The current pace of medical advances suggest within couple decades synthetic maternal surrogates capable of developing an embryo into a healthy adult could be reliable.

Sending embryos would eliminate the need for very high speeds and would allow missions with multiple possible destinations (chosen upon closer inspection) or even with open ended ultimate destinations.

Sending embryos could allow genetic modification to better adapt to conditions on planets while approaching.

The fear that mankind is on the brink of destroying ourselves here with no hope of recovery seems pretty widespread and it isn't a new phenomena. It is likely to continue and it isn't an unlikely scenario that small masting vehicles designed to last hundreds or thousands of years could begin regular launching within 200 years marking the end of your containment and beginning a great expansion of our infestation. The wars and resource exploitation of the Great Galactic Space grab will change the face of our corner of the galaxy with a few thousand years.

Or not.

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#3
In reply to #2

Re: The Helical Engine: will it work?

10/21/2019 7:14 AM

People think the Earth is going to be destroyed in 50-60 years...

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#8
In reply to #3

Re: The Helical Engine: will it work?

10/21/2019 11:43 AM

The "same" ones said that 50 years ago too.

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#9
In reply to #8

Re: The Helical Engine: will it work?

10/21/2019 1:03 PM

No, it's only been 44 years.

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#23
In reply to #8

Re: The Helical Engine: will it work?

10/24/2019 11:14 PM

"end of days" has been predicted for millennia!

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Guru

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#4
In reply to #2

Re: The Helical Engine: will it work?

10/21/2019 9:10 AM

Goldfish will adapt to the size of their container.Put a small goldfish in a large pond,and he will grow to a very large size.They are responding to the feedback from their own waste into the water containing them.There will come a point when our own waste will inhibit our growth,population wise.The land and oceans and atmosphere have almost reached a tipping point of no return.The ice is a great temperature modulator;when it is all gone,the Earth will really begin to heat up at an accelerated rate.

IMHO:

If we learn to preserve our own fish bowl,we may survive long enough to leave our solar system,and perhaps our own galaxy.If not,we will suffer a great population decline at our own hand,and we will revert to a previous level of civilization,if we survive at all.

If we survive long enough,genetic modification will enable very long lifespans,and virtually disease free bodies.The use it or lose it nature will be overcome,and one will maintain a youthful body,however,humans may become a hybrid of machines and biology,even down to the nano-machine level.

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#10
In reply to #4

Re: The Helical Engine: will it work?

10/21/2019 1:48 PM

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#11
In reply to #10

Re: The Helical Engine: will it work?

10/21/2019 2:09 PM

That is the biggest all gold goldfish I have ever seen!

I have seen the normal variety moved into a larger tank,and they grow larger,but become blotched with gold and white areas.

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#27
In reply to #10

Re: The Helical Engine: will it work?

02/15/2020 9:13 AM

He said catching the gold fish was easy.

It was catching that 5 pound gold cricket for bait that was hard.

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#7
In reply to #1

Re: The Helical Engine: will it work?

10/21/2019 10:05 AM

The direction of travel of <...a large interstellar meteor...> on which one might <...hitch a ride...> may well be something other than the destination of preference.

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#5

Re: The Helical Engine: Will It Work?

10/21/2019 9:14 AM

As the NASA author states, this is not a practical engine. As for the question, will this produce any thrust at all? I expect any thrust effect from rapid changes into and out of relativistic velocities will be smaller than any of a number of mitigating factors. For instance;

  • The energy required to accelerate these particles comes from and goes somewhere. I expect this transfer of energy will impart a bigger effect than this.
  • A change in velocity to 0.99995 of the speed of light will produce a 100 fold increase in the mass of these two particles. However, the machine required to spin these particles up to this velocity will be more than a hundred orders of magnitude greater in mass than this tiny two orders of mass increase.
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#13
In reply to #5

Re: The Helical Engine: Will It Work?

10/21/2019 6:05 PM

The energy required to accelerate these particles comes from and goes somewhere. I expect this transfer of energy will impart a bigger effect than this.

I'm not too worried about the energy, but where does the momentum come from? A huge amount of science is based on conservation of momentum.

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#14
In reply to #13

Re: The Helical Engine: Will It Work? Electromagnetic Momentum Engine

10/21/2019 11:31 PM

Electromagnetic Momentum Engine

Indeed, "A huge amount of science is based on conservation of momentum."

This video calculates photon momentum. It strikes me that by conservation of momentum all one has to do to propel a spacecraft is to generate a non-symmetric electromagnetic illumination of space in the opposite direction of the desired direction of travel. By conservation of momentum the spacecraft must receive a momentum vector opposite the radio/light/x-ray beam momentum due to the generated beam. Simple and probably the explanation why the Helical relativistic engine will not work. Accelerated charges (the circulating ions in this case) are very likely to radiate and the radiation produced is likely to cancel the propulsion of the varying mass oscillation leaving the momentum inside the box a constant.

So Rixter, I agree but now we have a leap forward from the ion engine which must deplete some ion source of mass from inside our box. Ion engines probably generate charge imbalances between the craft and its ejecta as well which will tend to decelerate the craft and force ejection of ions of the opposite charge at some level of scaling or risk deceleration and/or lightning strikes. Optimization of two different ion engines or making one ion engine spew two oppositely charged ions is also a headache. Running a radio antenna with an asymmetric radiation pattern is OTOH something we do all the time as easily as falling off a log.

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#16
In reply to #14

Re: The Helical Engine: Will It Work? Electromagnetic Momentum Engine

10/22/2019 10:39 PM

You're right, photons of energy E have momentum p = E/c, and can be the propellant of a photon rocket. Doing the math, for 1 newton of thrust (0.225 lb), requires about 300 Megawatts of energy.

Granted one of the practical problems is radiation from spinning those ions, but that's a detail. The principle of the design doesn't require ions, it's just that charged particles are the easiest to accelerate.

The problem is not practical, but theoretical.

The design says that you have a loop of ions and that speeding up or slowing down the loop changes the mass. This is correct, a result of the theory of Special Relativity.

But, where does this extra mass come from? It comes from part of the energy that is used to accelerate those ions, m = E/c2. Energy has mass. This is the key to the puzzle.

Let me try to simplify. The helical engine works on the following cycle:

1. Move ion ring to front,

2. In front, apply energy to speed up, increase mass,

3. Move ion ring to back,

4. In back, remove energy to slow down, decrease mass, return to #1.

The helical engine is moving more mass front to back to generate forward thrust. But the energy used to change the mass of the ion ring is moving from back to front, generating backward thrust. The mass of this energy is exactly the same as the change of mass of the ion ring. There is no net thrust.

Conservation of Momentum lives another day.

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#18
In reply to #16

Re: The Helical Engine: Will It Work? Electromagnetic Momentum Engine and Cheshire Grins

10/23/2019 9:41 AM

Photon Mass is a Cheshire Grin

"The mass of this energy is exactly the same as the change of mass of the ion ring."

Yes, just like you, I think it is impossible to separate energy from its E=m*c*c mass but the "traditional wisdom" is that electromagnetic energy is carried by "massless photons" which is a pedagogy the powers-that-be seem to want to adamantly insist upon. I thought I would dance around this conundrum by focusing on the momentum of the photons which the video facilitates without shoving the mass of the energy into any new imaginary particles popping in and out of existence between parallel universes(a practice I consider to be hand-waving.) I think that photons carry mass but that mass is not scalarized by any detectable zero-spin bosons(Higgs.) I have problems denying that mass is present in the one-spin bosons(photons) and choke at the popular reluctance to accept that the "disembodied mass" is still moving along inseparably with its photons.

Just like through the looking glass Alice, I think one has to be careful about the thing, the name of the thing, and what you call the thing in order to keep others happy. I can jokingly visualize the smile of the Cheshire cat zooming through space as I personally accept the mass "carried along" with the photons of electromagnetic energy propagating through space. I yearn to cease being forced to amend my language to appear to deny photon mass. Perhaps you know the magical verbal nuance that constitutes the accepted pedagogy for denying photon mass while still using it to describe mass transfers in which the photons are participating.

==============================================

"Doing the math, for 1 newton of thrust (0.225 lb), requires about 300 Megawatts of energy."

This may seem like a lot of energy for a tiny amount of thrust. If you take the mass thrown out by an ion engine and do the E=m*c*c transform on the lost mass, the 300 Megawatts no longer looks so extreme. In either case, it may be unhealthy to fly in a straight line formation directly into the thrust of the craft you are following. The long term junkyard problem is probably worse than our defunct terrestrial satellite trash orbiting the earth and way harder to travel to in order to implement cleanup. I know people will perceive space as an infinite junkyard which we never will impact but that is the same thinking which lead to the Pacific Ocean junk gyre. Funny how these junkyards, when scaled up enough all look like galaxies. It will be amusing if the celestial beauty we are looking at through our telescopes turns out to be forensic images of primordial thrust artifacts left where really advanced ET's traveled more than 13.7 billion years ago just before the whole thing collapsed in one great entropic garbage implosion.

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#22
In reply to #18

Re: The Helical Engine: Will It Work? Electromagnetic Momentum Engine and Cheshire Grins

10/24/2019 11:44 AM

The photon has no rest mass but does have momentum and energy, and the energy has to have mass, m=E/c2.

"A so-called massless particle (such as a photon, or a theoretical graviton) moves at the speed of light in every frame of reference. In this case there is no transformation that will bring the particle to rest. The total energy of such particles becomes smaller and smaller in frames which move faster and faster in the same direction. As such, they have no rest mass, because they can never be measured in a frame where they are at rest. This property of having no rest mass is what causes these particles to be termed "massless." However, even massless particles have a relativistic mass, which varies with their observed energy in various frames of reference,"

https://en.wikipedia.org/wiki/Mass_in_special_relativity#targetText=For%20other%20frames%2C%20the%20relativistic,the%20faster%20the%20body%20moves.

Note that E and m=E/c2 becomes smaller in frames which move in the same direction as the photon. The Doppler redshift is equivalent to lowering the energy of the photon and its relativistic mass.

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#24
In reply to #16

Re: The Helical Engine: Will It Work? Electromagnetic Momentum Engine

10/27/2019 11:03 AM

On the other hand, if you accelerate the ions at the front from an onboard energy source (located at the front) and throw away the energy obtained from decelerating the ions at the back rather than trying to recirculate it as in #16, preferably beamed backward as photons, you should get forward thrust, Thrust = Power / c.

It would basically be a photon rocket with the reaction momentum routed through the relativistic mass of spinning ions. This would not violate any physical conservation laws.

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#25
In reply to #24

Re: The Helical Engine: Will It Work? Electromagnetic Momentum Engine

10/27/2019 12:28 PM

Fusion Beta Particle Accelerator Radio Transmitter

Yes, I can imagine such a photon rocket working. It may even
have desirable power characteristics. I wonder if it could
be pumped (the energy source at the front) by some means which
would not require that energy source to be or be converted to
electricity. If, say, nuclear fusion could be used without
going through conversion to heat, operating a steam engine,
operating a generator, and then using an electrically driven
ion accelerator and decelerator then it is plausibly better
than a fission reactor going through all those intermediate
conversions in at least two different fundamental ways.

First,
micro nuclear fusion might avoid a lot of containment gyration.
This might make useful fusion power generation possible without
notoriously unstable and expensive full-enclosure magnetic bottles.
Second, the product of the fusion might be useful (perhaps fusion
end products like Oxygen or Iron) in contrast to the dangerous
nuclear "waste" from extant fission reactors.

If one cannot achieve these accelerations/decelerations without
passing through an electrical energy phase then it may be better
to use a powerful radio transmitter with a beam-forming antenna
instead since that may be more efficient(or not) than driving
the accelerator intermediate step. OTOH, if one conceives of a
radio transmitter as an electron accelerator/decelerator, it may
conceptually be the same thing as a Beta particle generating

fusion process where the ion accelerated is the created beta particle.

Better still might be a fusion reaction which produces a photon (probably

a hard x-ray) if you could manage to beam those in a chosen direction.

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#6

Re: The Helical Engine: Will It Work?

10/21/2019 9:27 AM

The space shuttle deployed a tether to measure the energy that could be captured while orbiting the Earth.The first tether broke due to unexpected stress.The second one was successful and they discovered that taking energy from the tether would decrease the orbital speed,and pumping energy into it would increase orbital speed.The energy was generated by the tether bending magnetic lines of force as it orbited the Earth.

Space is full of moving magnetic fields from our sun and other sources.

Every solar flare would give a boost in velocity.

Why not devise a method,perhaps a large coil, and nuclear energy to use these ever present fields for propulsion?

No need to expel propellant.

Just thinking out of the box.

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#12
In reply to #6

Re: The Helical Engine: Will It Work?

10/21/2019 3:56 PM

The purpose of the coil would be to generate a repulsive magnetic field to oppose the plasma magnetic field from the sun.

The coil would be powered by a nuclear reactor.

Would this work?

"He that controls magnetism will control the universe."...Chester Gould

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#19
In reply to #6

Re: The Helical Engine: Will It Work?

10/23/2019 10:03 AM

Well, if you're near a star, there's a free ride from photon pressure

https://en.wikipedia.org/wiki/Solar_sail

Here's another interesting concept...

Generate a magnetosphere with a magnetic field and cold plasma which can capture solar wind, Mini Magnetospheric Plasma Propulsion (M2P2)

https://science.nasa.gov/science-news/science-at-nasa/2000/ast04oct_1

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#20
In reply to #19

Re: The Helical Engine: Will It Work?

10/23/2019 10:34 AM

Thanks for the link!

Using the magnetic field from the sun is what I was talking about,but I did not know about the need to create an ionized cloud to expand the bubble.

Sounds like a great idea,especially since the ionized cloud expands at the same rate as the magnetic field decreases,giving constant propulsion regardless of distance.

Day late,dollar shy as the saying goes.

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#15

Re: The Helical Engine: Will It Work?

10/22/2019 9:43 AM

My completely unadvised impression is this:

BIG - it would have to be really, really big. Like half the size of the moon.

TIME - it would take a very long time to accelerate unless it utilized gravitational sources as its initial acceleration energy

For maintaining an already achieved speed, this might work.

But again: BIG, really BIG.

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#17

Re: The Helical Engine: Will It Work?

10/23/2019 6:21 AM

Looking at the "top down" view, there might be an initial movement to a new "centre of mass" that seems to be at most 12.5% of the cycle displacement, but then a new equilibrium becomes established.

There might also be force in the other vector directions.

I also suspect that when the excitation is removed, then the device would revert to the original position and orientation.

Think of the experiment with a free spinning bicycle wheel. If the axis is changed, the wheel when released returns to orientation and location.

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#21

Re: The Helical Engine: Will It Work?

10/23/2019 12:22 PM
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#26

Re: The Helical Engine: Will It Work?

10/28/2019 2:44 PM

Thrust of Rockets is not the only way to travel.

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