NASA engineer's 'helical engine' may violate the laws of physics

[editor]

Fascinating idea this.

For every action, there is a reaction: that is the principle on which all space rockets operate, blasting propellant in one direction to travel in the other. But one NASA engineer believes he could take us to the stars without any propellant at all.

Designed by David Burns at NASA’s Marshall Space Flight Center in Alabama, the “helical engine” exploits mass-altering effects known to occur at near-light speed. Burns has posted a paper describing the concept to NASA’s technical reports server.

It has been met with scepticism from some quarters, but Burns believes his concept is worth pursuing. “I’m comfortable with throwing it out there,” he says. “If someone says it doesn’t work, I’ll be the first to say, it was worth a shot.”

To get to grips with the principle of Burns’s engine, picture a box on a frictionless surface. Inside that box is a rod, along which a ring can slide. If a spring inside the box gives the ring a push, the ring will slide along the rod one way while the box will recoil in the other. When the ring reaches the end of the box, it will bounce backwards, and the box’s recoil direction will switch too. This is action-reaction – also known as Newton’s third law of motion – and in normal circumstances, it restricts the box to wiggling back and forth (see video below).

Read more: NASA engineer's 'helical engine' may violate the laws of physics

At the moment, his designs seem pretty far out. After all, this is his pet project, not NASA’s, and he knows that some will be skeptical of the idea. “I’m comfortable with throwing it out there,” Burns told New Scientist. “If someone says it doesn’t work, I’ll be the first to say, it was worth a shot.”

First, the design would only be able to work up enough momentum in space, a completely frictionless environment. Were it on Earth, it would require a ton of power—about 125 megawatts, or enough energy to power a small city—to achieve just one newton of energy, the same amount of force it takes to type on a keyboard, according to New Scientist.

A NASA Engineer Wants to Use a Particle Accelerator to Power Rockets

 

[Don Troooomp]

Not tossing wild ideas into the hat is a recipe for not advancing in any and every field.
Good luck to them.

 

[8ball]

You will not believe the INSANE prices my magic beans are on sale for!

tbf. it's a fun idea

It's like you're on a rowboat, you and your mate have a bowling ball, you sit on the front, facing back, your mate at the back, facing front.

You repeatedly roll the ball gently back to him, then he chucks the bowling ball really hard back at you and you catch it. This should move the boat forward, right?

 

[8ball]

Not tossing wild ideas into the hat is a recipe for not advancing in any and every field.
Good luck to them.

And if people were had been less open-minded we'd never have had the ADE-651 bomb detector.

 

[gentlegreen]

You will not believe the INSANE prices my magic beans are on sale for!

tbf. it's a fun idea

It's like you're on a rowboat, you and your mate have a bowling ball, you sit on the front, facing back, your mate at the back, facing front.

You roll the ball gently back to him, then he chucks the bowling ball really hard back at you and you catch it. This should move the boat forward, right?

plane takes off

 

[andysays]

I cannae change the laws o' physics, Captain...

 

[gentlegreen]

Wasn't it a "NASA scientist" who found "space fossils" a while back ?

 

[8ball]

Wasn't it a "NASA scientist" who found "space fossils" a while back ?

Well, the thing with their "tech experts" area and other smilar forums is that they get all manner of mad ideas, and hopefully. possibly a great one now and then.
Sometimes two mad ideas can be combined into something that actually kind of works. Brainstorming, innit?

"Space fossils" has been used to refer to a few things, from traceable early-universe energy ripples, to interesting tell-tale stuff inside meteorites (chemical composition, crystals etc.), to alleged space rocks with alien skeletons in, so not sure what you're talking about specifically here.

 

[Crispy]

For every action, there is a reaction: that is the principle on which all space rockets of known reality operates

Any propellantless propulsion method is by definition an infinite energy machine.
Reason:
Velocity goes up linearly with every Joule expended, but kinetic energy goes up with V²
When mV² is greater than total energy input, brake the device to a stop and extract the kinetic energy. Voila, free energy.

Infinite energy machines are impossible. It is one of the few truly certain things in physics.

I'll let the specialists poke holes in this, but I would happily bet everything I owned on this device not working.

 

[ferrelhadley]

Fascinating idea this.

A NASA Engineer Wants to Use a Particle Accelerator to Power Rockets

This is action-reaction – also known as Newton’s third law of motion – and in normal circumstances, it restricts the box to wiggling back and forth (see video below).

Newtons third law I think the assumptions in the way the article is using it only work like that in inertial frames of reference where speeds are low enough that the Lorentz Transformation can be ignored. This theoretical device explicitly needs to be accelerating to velocities where its mass is notably changing to observers at the frame of reference of the "box" or what ever it is.
As a property mass dependent on the frame of reference of the observer. But among the issues this seems to have at a minutes glance is that as the velocity of the box is increased the forward velocity of the "ball" or helix of particles or whatever will appear to slow in the forward direction but increase in the reverse.
For an observer outside the boxes frame of reference the box itself will be gaining mass.
Without getting out a pencil and rubber and jumping head first into the various changes in mass and relative velocities from differing frames of reference I cant say this is wrong, but I suspect these issues may play a role.

Non propellant propulsion kind of exits, light sails are one form of it. There are other theoretical ideas around. It kind of depends on how you define propellant and mass (i.e. photons have no rest mass but they do have momentum.) so you can end up dancing round the houses with various people on the internet trying to work out what each other is saying.

(this post is quick and dirty and likely will need a rewrite after some thinking. )

 

[ferrelhadley]

Velocity goes up linearly with every Joule expended,

I do not think this is true?
momentum increases at a rate of m*v thus p=mv. That is measured in kg*m/s

but kinetic energy goes up with V²

KE=1/2mv^2
That is measured in kg m^2/s^2

You could only extract the total energy of the kinetic energy as a theoretical absolute. Practically there is far too much friction in the system as entropy always has its pound of flesh.

In a friction free system the kinetic energy would only be able to increase and decrease by a factor of the square of the velocity.

But this relies on accelerating some kind of particle ring and a "box" to near the speed of light and there, the maths gets a touch more complex. Good luck finding a material that could accept the energy of a mass of particles large enough to provide velocity with the electrons on the surface becoming "excited", the absorbing surface rather warm and a host of other challenges. Id there and the above post would be places where this will likely fall down.

But as always your mileage may vary.

 

[8ball]

Maths! Yay!

Expecting an entertaining post from 2hats at any moment...

Edit: I don’t think you need to go into the vagaries of the Lorentz transformation in much depth since by my reading it is purely employed as a “mass-effect drive” MacGuffin.

 

[ferrelhadley]

I will try to have a more coherent crack at this.

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


Having dug around for a couple of minutes...
The "accelerator" what ever that is has a reaction force in the opposite direction to the particle it is emitting. This "accelerator" will have to be fixed to the "ship" or whatever in someway thus I think this is the rather simple explanation for where the two forces are.

•Hypothesis: “IF engine continues to accelerate, THEN engine’s momentum continues to increase.”

Within the frame of reference of the ship it is not accelerating. The speed of light is always 3*10^8m/s in any direction of travel as you are when you were "stationary". You never get faster with relation to the speed of light. The accelerator is always emitting the particle at the same fraction of the speed of light. There is no moment increase from the frame of reference of those on the starship.
From the perspective of a stationary* observer, as the starship will gain mass as it gets closer to the speed of light from our perspective. The particle emitting from the accelerator will also get faster but this is not linear but its extra speed over the starship will decrease.
While the particles will appear to get faster and gain momentum, so will the starship and the accelerator.

Either I have not understood this or there are two elementary problems in it detailed above. But the details here are sparse and I may have missed something.
*Technically one who has not undergone acceleration

 

[Crispy]

From here:
Helical Engine

Quote from: AnalogMan on 2019-10-14, 20:20:01
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:
NASA Technical Reports Server (NTRS) - Helical Engine
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.

 

[beesonthewhatnow]

 

[Crispy]

Near-infinite specific thrust from drive that ignores physics

 

[fishfinger]

Near-infinite specific thrust from drive that ignores physics

Love the illustration in that article

 

[8ball]

Near-infinite specific thrust from drive that ignores physics

I like the fact that despite ignoring physics it still needs to be fucking massive, is hugely inefficient, and puts out hardly any power.

I can piss on that effort in two words: warp drive.

 

[NoXion]

OK, here's the thing that puzzles me. If 1) energy is always conserved, 2) empty space has energy; whether it has a lot or a little seems to depend on how you measure it, but the point is that it's not completely devoid of anything, and 3) more space (and thus more energy) is being generated ex nihilo in the universe (somehow) as it expands. Then...

Does this not then mean that conservation of energy is being violated in a massive way? That what many people think of as some universal, iron-clad "LAW of conservation" is in fact just a particular way the universe behaves under specific conditions?

Given that potential loophole, I wouldn't entirely dismiss the possibility that some clever physicist might work out a way of applying it technologically. After all, an engineer can create conditions that would otherwise never have naturally occurred where human observers could readily see them.

Either that, or we live in a multiverse of some kind and that's where all the energy of our universe's ever-increasing volume is coming from. I've always been partial to multiverse ideas - I just wish they were easier to test.

However, in this case I am skeptical. The Emdrive (remember that? the journalists have, see the picture accompanying the article in the OP) has turned out to be bunk. I don't think our knowledge of the physical universe is sufficiently developed to allow spacecraft designers to so easily flip the bird at Newton and Einstein this side of the next millennium. Our understanding of physics as a whole is still split into two areas - relativity and quantum mechanics - which we still can't get to play nicely with each other mathematically, even though they both describe the same fucking universe.

I can piss on that effort in two words: warp drive.

Be sure to let me (and the Nobel Committee) know whenever you find a practical way of generating and directing the non-trivial quantities (possibly equivalent to a Jupiter mass or greater) of negative energy required for such solutions to work. I won't be holding my breath.

Warp drive would be cool and all, but even if it is possible I don't think it's happening for a good while yet. Too many gaps in our knowledge. Also, if we haven't worked out the Fermi Paradox by the time we invent warp drive, I for one would become extremely worried, especially since the dirty little secret behind FTL travel (no matter what mechanism is used), one ignored by the vast majority of science fiction writers (those fools), is that a spacecraft with FTL capabilities is also a time machine.

Also it would mean causality is an illusion, or at least that it only applies to certain objects, i.e. those with non-imaginary rest mass travelling at sub-C velocities along unclosed timelike paths.

I'm rambling, but I find this stuff fascinating, even if I feel that I don't have a proper grasp of it.