What Are the Implications of Reaction Torque Propulsion?

[krab]

The actions are rotating loads. A motor that turns a load produces a rotating force, in other words a couple. This has to be compensated by an equal and opposite reaction, in this case a couple that turns the hovercraft in the opposite direction. That is the essence of the device. A motor turns a load; that makes the hovercraft turn in the opposite direction.

So you appear to believe in conservation of angular momentum. Why do you not believe in conservation of linear momentum? As for us, Would we believe that conservation of linear momentum is true, or would we believe that a guy who has filmed a jiggling vibrating assembly of parts has disproved it? Now that's a toughie.

 

[enigma]

Yes they do, they use reaction wheels to maintain their attitude. They don’t have to push against anything to do this.

No. Try again.

The satellite torques the wheel. The wheel torques the satellite. The wheel speeds up. The satellite changes orientation.

So you implicitly agree that a rotary means of propulsion is not only feasible, it is in fact used in space.

Changing orientations by adjusting the potential energies of internal components is NOT propulsion.

BTW it is an erroneous notion that propulsion has to push against something. When in space rockets simply throw away their burnt fuel in space against nothing. All you need is an action to get a reaction. Get your notions correctly!

The rocket pushes against the fuel. The fuel pushes against the rocket. You do realize you're accusing an aerospace engineer of not knowing how a rocket works, right?

That is a quagmire I do not wish to go into.

Then don't expect anyone to shill out millions of dollars to test your device, and don't expect any of us to believe you've invented an infinite improbability drive.

 

[Chronos]

BTW it is an erroneous notion that propulsion has to push against something. When in space rockets simply throw away their burnt fuel in space against nothing. All you need is an action to get a reaction. Get your notions correctly!

A refresher course in rocket science may be in order. A rocket pushes against the mass of the propellent being expelled. Your device is going to flop around like a wounded toad and whatever linear displacement you manage to coax out of it will require a huge amount of energy compared to a device such as a rocket.

 

[russ_watters]

The rocket pushes against the fuel. The fuel pushes against the rocket. You do realize you're accusing an aerospace engineer of not knowing how a rocket works, right?

...and a mechanical engineer of not understanding torque. And most of the rest of the guys who have posted in this thread are either physicists or engineers. In another universe, that would be funny...

Ray, it appears I was wrong - you need to learn what conservation of energy/momentum is, as well as how torques/couples work in machines. I had hoped you would know Newtonian mechanics - its learned in high school physics and should even be intuitive.

There is an enormous amount of information on the internet about these two subjects. Please, please avail yourself of the resources and learn about these two concepts. Google works: http://www.mcasco.com/QA15.html is a start.

To help you think about the rocket situation you mentioned in your email we need to talk a bit about cause and effect. The conservation of linear momentum is one of those things very near to the heart of what makes the universe work. For our purposes it is a cause, not an effect. That means we do not say linear momentum is conserved because... Rather we say this or that happens because linear momentum is conserved. If we take the conservation of linear momentum to be a "law of nature" then we can conclude all sorts of interesting things from that.

Suppose for example that we have a rocket loaded with fuel, initially at rest in our frame of reference. When we start the engines, some of the fuel is ejected at high speed from the exhaust of the rocket. The exhausted fuel now has some linear momentum in our reference frame. The total linear momentum before the firing of the engines was zero. Since it is conserved, the total must remain zero. This means that the momentum of the fuel in the backward direction must be exactly balanced by the momentum of the rocket in the forward direction. Therefore the rocket moves forward.

This concept applies to your hovercraft as well - it moves forward, therefore something else must move in the other direction, or it must push against the table. Take your pick.

For the concept of a "couple" vs a "torque", look http://www.engin.brown.edu/courses/en3/Notes/Statics/Forcecouple/Forcecouple.htm. You're misusing the concepts.

We have seen that a force acting on a rigid body has two effects: (i) it tends to move the body; and (ii) it tends to rotate the body.

A natural question arises – is there a way to rotate a body without moving it? And is there a kind of force that causes only rotation without translation?

The answer to both questions is yes.

5.1 Force couples

A system of forces that exerts a resultant moment, but no resultant force, is called a force couple.

Couples cannot cause translational motion - but then, what is happening on your device isn't couples anyway - its torques.

 

[russ_watters]

Ray, in my searches, I have found you have discussed this at length on other forums. The answers the scientists and engineers are giving you on other forums are the same as the answers we are giving you. I really need to know: is there anything that any expert can tell you that would convince you that your device is moving because of something other than "reaction torque propulsion"? If not, its useless to continue trying to explain it to you.

Or, failing that, how many experts does it take before you will believe one?

Further, you clearly have put a lot of energy into this - put some energy into learning the physics and engineering behind it.

 

[mapper]

shesh, when this gets locked "Theory vs. Math (possible/impossible)" is the only thead people are going to be able to post in!

wtf is up with all the locked threads anyway? Let people post if they wish. If its dead it will die on its own!

 

[enigma]

wtf is up with all the locked threads anyway? Let people post if they wish. If its dead it will die on its own!

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[Doc Al]

And on that note: thread closed.