Are Reactionless Space Drives the Future of Propulsion?

[ubavontuba]

Maybenot,

I suppose you can start by defining the the force acting on the system. Where does it come from? What are its characteristics? What is its source?

See? It's too easy to mentally introduce an imaginary force that doesn't have to answer to the conditions of the system.

In a real space environment, this force must come from something, somewhere. Whether it be rockets, ion beams, meteor showers, or whatever, it introduces added mass and energy to the system that must be accounted for if we are to consider the system in full isolation. You can't just "(whatever)" it into irrelevance.

Think about it like this. If your pivot was motorized such that all the energy of opening and closing the "V" came from an internal source, what would happen?

In your last example, whether you realize it or not, the center of gravity will not move. "Raising" two arms does throw the apparent center of mass (the pivot) "downward" in relation to the system's boundaries more than closing the two lower masses together "raises" it, but the compensation will be that the pivot will apparently move "downward" and, in fact, the boundaries move in perfect sync to the center of mass which while only apparently moving "downward" is compensated for by the redistribution of weight around the center of mass. Therefore what is really happening is that the center of mass for the system is changing in relation to the mass distribution, but not in relation to the center of gravity. Your mistake is probably in viewing the pivot as representing the center of mass irrespective of the mass distribution around it.

Overtime, I've seen a lot of ideas like this come and go. They don't work. There is a fun way to experiment with these concepts though. I recommend that you download this free http://Newton.delphigl.de/Newtonplayground.html. Although it's designed to be a game driver, it can be used to conduct quite accurate physics simulations. For zero-g space, set the gravity to zero, delete the floor and make sure all of your objects aren't dampened (by default). You can then design, build, and test your ideas in a zero-g environment. If they propel themselves in this program (without pushing on anything), that would be very interesting... indeed.

P.S. Before you go there, having the masses on the ends be gyros has been investigated. No resultant propulsive properties were noted.

 

[Maybenot]

More than meets the eye

Your observations are general and don't address the specificity of this case. The nature of the force is irrelevant. It could be a spring, it could be electromagnetic, etc since what we study are the interaction and the velocities after impulsion.
The question is this: After impulsion, at T+∆t, what are the linear accelerations (y axis) of the bodies going up, the bodies going down and finally of the pivot? (mass of pivot = mass of 2 bodies)
For the momentum to be conserved, the acceleration of the pivot has to be twice the opposite acceleration of either pair of bodies. How can the pair going "up" accelerate the pivot more than its own acceleration? THAT is the question
It's nice of you to say that the center of mass (or gravity) will not move anyway, but can you answer the question? Just give me the ratios of the acceleration of the bodies vs the acceleration of the pivot at a given time after impulsion.
That shouldn't be so difficult.

 

[Maybenot]

And by the way, we had it modelised with I-DEAS, an industrial digital modelling tool, by an independent company. The software is used to design racing cars, machines, etc.

 

[ubavontuba]

No, I quite directly addressed the specifity of your case. The nature of the external force acting on your system is entirely relevant. If you think you can just pretend that any part of the system is irrelevant, then so can I. Therefore I declare the mass to be irrelevant. What now?

The relative velocities of the bodies going up and down is truly irrelevant though. You are making the mistake of thinking of your bodies as individual entities. They are not. They are all part of an interconnected, single mass that can change shape and change it's internal mass distribution... and that's it. The assembly as a whole cannot accelerate without expelling mass/energy. All it can do is wobble all about.

As far as your computer simulation is concerned; garbage in = garbage out. Simply the fact that you regard the force acting on the device to be irrelevant tells me that it's garbage. If you paid for the service, you were ripped off.

Use that free download to model it and send me a copy of the file. Someone else did this with a very similar concept. I had fun watching it wobble all about.

I think the real issue for you is that it seems naturally intuitive that systems like this should work. This is probably because our intuition is based on earthbound systems. That is to say that our intuition fails us in an isolated space environment. It's common to think that swimming motions can propel you in space like they do in water. This is not true... and your concept functions very much like a swimmer in water. You have a central mass (torso), two lower extremities that are close together (legs), and two upper extremities with a greater range of motion (arms)... much like a person! Do you see how your intuition misled you straight to an example of your own body propelling itself through a liquid medium (the closest earthbound analogy to a zero-g environment)?

Anyway, I understand that you probably feel that I'm being obstinate and am blinded to the fact that you're the guy that beat Newton. Whatever. I've been there myself too. If you're smart you'll see the futility of it in a year or so and move on to other things (I have). Otherwise you'll doom yourself to a life of frustration... and perhaps madness. As an example, check out this http://www.forceborne.com/FBW/principle.htm" ".

Don't feel too bad though. Many quite ingenius people have been caught up in these mind traps. Newton himself spent the latter part of his life in futile pursuits. The list of engineers and scientists that have pursued these concepts is quite extensive. In fact I'm considering the notion of writing a book on it.

Lastly; the moderators here don't much like me and your ideas go beyond speculative (they're just plain wrong), so I suspect they may soon lock this thread. If this happens feel free to send me personal messages and we can continue discussing this privately.

 

[Maybenot]

Thanks for the advice, I'll send you something in the next few days. Actually, I don't feel like the guy who beat Newton because this no about wether Newton or anybody else is right or wrong. This is about one thing and one thing only: What are the accelerations of the bodies and the forces those bodies exert on each other. The rest is just feelings. No need to lecture, just sit down with a pen and a piece of paper.
Anyway, no need to end the thread, I am out of here.

Talk to you later.

 

[ubavontuba]

Maybenot,

Without intending to lecture: You might as well examine how much acceleration force you can apply to yourself by pulling on your socks.

Have you conducted any research to determine if any similar concepts have been proposed?