# Novel methods for propelling a rocket

Discussion in 'Physics & Math' started by Rocket Paul, Sep 23, 2017.

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56

3. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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10,579
If we used your idea this is the sequence of events that would happen.
1. The interior rocket would fire and begin to rise.
2. There would be a repelling force between the magnets that is transferred to the outer skin so that the entire inside and outside would lift.
3. The distance between the magnets would fluctuate for a short while and then reach equilibrium and the distance would remain constant.
4. The system would function as a normal rocket that was using magnets to transfer the thrust to the outer skin.
5. The same thing could be accomplished by simply physically attaching the interior to the exterior.

But there is no reason add the extra weight of the outside skin to begin with.

5. ### BaldeeeValued Senior Member

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1,379
When you move the magnet in your hand toward the car you apply a force from your hand, via the magnets, to the car.
So let's say push the magnet in your hand with a force of F toward the car/magnet.
The force you apply (F) will then impart acceleration to the car/magnet according to F = Ma.
If you didn't have the magnets and applied the same force F directly to the car then the car would be given the same acceleration.
The magnets do not help increase the force applied.

Try it yourself.
Do the experiment that you describe above.
Then do it without the magnets, where the same force is imparted directly to the car.
To be honest, you really aren't listening to what people are explaining to you, and you seem to have no genuine desire to understand even the basics.
Can I suggest that you go to your nearest school and ask a physics teacher, someone who is paid to explain the basics that you're lacking, as maybe you'll listen to them.

7. ### ArafuraOpalRegistered Member

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20
A rocket is a closed system. If I were standing inside a rocket at the front and threw a heavy ball towards the back, it would produce an initial forward motion on the rocket, but when the ball hit the rear of the rocket, it would stop any forward motion. Bringing the ball from the rear and back to the front would reverse the forward motion so that you are back to where it was. All you are doing is moving the centre of mass of the rocket around, and the centre of mass is what obeys Newtons laws of motion with the rocket as a closed system. You need an external force on the rocket if the rocket's mass were to stay the same.

8. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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So, essentially, "La la la I can't hear you".
Good luck.

9. ### Rocket PaulRegistered Member

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56
Well thank you Origin pity this was not said earlier instead of all the insults I would have taken it on the chin and walked away, it was not easy to do that when it was said no no no to every aspect of the system.
Look I get it where everyone is coming from the very reason I started this chat and it looks like the main question I had about the magnets giving a build up of momentum with a continuous force applied is still unknown because no one has never been able to do it, go back to the toy car and the hand held magnet platform 1 and the fixed magnet on the car platform 2, platform 1 is our engine and platform 2 is the craft, both tests are the same, yes I know in the system platform 1 is held in position by the engine but platform 1 is free moving and not attached to platform 2 although it is resting inside on the guide rails and yes the thrust is coming from the back on the outside of the craft but to lift the craft it has to be done via the magnets from the top, so all I say is feasible.

I will depart this conversation now and leave you all in peace.
Paul

10. ### BaldeeeValued Senior Member

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1,379
There is a simple reason why no one has been able to do what you propose: it is not possible.
It is not a question that is unknown until someone can do it, but rather no one can do it because it is known to be impossible.
It goes against the most basic of physical premises: conservation of energy.

No matter how hard you try you will not get 2+2 to equal 5, not because it is still unknown as no one has ever been able to do it, but because it is impossible.
It is feasible only in as much as it is a system that you could build, but not feasible for it to work the way you imagine, as in giving any improvement in efficiency etc.

Furthermore you have failed to address any actual criticisms of your approach, and instead just keep repeating it over and over again, albeit now using cars rather than the rocket.
At no point have you actually laid out any maths, any equations, any formula, to show how you think it might work.
As a result myself and others here have detailed to you in similar laymen's terms why it won't work.

If you wish to keep your head in the sand and think it a feasible idea, that is your prerogative.
I don't think anyone here will waste any more time on you until you can show you actually want to listen.

But I also suggest you take time away to go and do the math behind your idea.
And do the math behind a conventional rocket so that you can see where your efficiencies might be.

11. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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You mean apart from where the errors in your claim were specifically pointed out? I (not Origin) resorted to "No, no, no" sometime AFTER it had been explained to you and you persisted in making exactly the same claims (without support).

You say this, and then continue with:
No, it's not "unknown"; it HAS been explained to you.

Yeah, you say it's feasible because you "get where everyone is coming from"...

12. ### originIn a democracy you deserve the leaders you elect.Valued Senior Member

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10,579
Well at least you are saying that you now 'get it' so that is good.
Hmm, now in the same paragraph you are saying you don't get it?

This is why you are getting insults - you are a frustrating poster!

13. ### billvonValued Senior Member

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14,528
Right. But launching a rocket is not like balancing an empty pipe in 1G of gravity. Rockets fly in zero G - and the only acceleration they provide is from their own engine. And in that case it's easier to have the rocket on the bottom for steering/stability purposes.

Robert Goddard initially thought as you did; his engines were in the top of the rocket for "stability." Once he learned a little more about how rockets worked, he moved his engines to the bottom - because they worked better there. You should take advantage of that learning.

14. ### DaveC426913Valued Senior Member

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9,762
Math isn't even necessary to understand why this won't work. All you need to have is an understanding of Newton's Three Laws.
The OP is not applying them correctly, and thus keeps concluding he can get something for nothing.

15. ### Rocket PaulRegistered Member

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56
Guys I came here today to leave the group but I can't see how to do it so if someone can do this for me I will appreciate it.

Before I go I will have my last say on the matter.
Do the maths you say why bother when I have done the test, I have done the tube test with a fixed magnet at the top "sealed end" and pushed the stick up the pipe from the open end with a repelling magnet on the end of the stick and guess what it works the rocket is levitated from the free moving magnet on the stick "engine" so unless there is some other force other than the engine whats levitating the craft, the test is exactly the same as the rocket applying initial force as the hand holding the stick, the engine travels along with the craft but its not fixed "two platforms" to the craft, guess what ? there is also perfect balance to move as slow or as quick as you like when doing the test so like I said in the beginning "how to lift a rocket from the top" I am not interested in what good or no good will come from lifting a rocket from the top but its like I say.

All I can say is do the test yourself and prove the theory.

If we used your idea this is the sequence of events that would happen.
1. The interior rocket would fire and begin to rise.
2. There would be a repelling force between the magnets that is transferred to the outer skin so that the entire inside and outside would lift.
3. The distance between the magnets would fluctuate for a short while and then reach equilibrium and the distance would remain constant.
4. The system would function as a normal rocket that was using magnets to transfer the thrust to the outer skin.
5. The same thing could be accomplished by simply physically attaching the interior to the exterior.

But there is no reason add the extra weight of the outside skin to begin with.

Correct up to no 5.... without a free moving rocket "engine" the force will be from the bottom and not transferred as you say at no 2.. .

Last edited: Oct 24, 2017
16. ### KittamaruSuppose it makes sense. Wearing a bit thin.Valued Senior Member

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13,937
If by "leave the group" you mean delete your account at SciForums, there is no method by which to do so. You can reach out to JamesR or report one of your own posts requesting a permanent ban if that is your wish, but otherwise, it'd come down to you simply walking away and not coming back (something a lot of people have said they would do, yet they almost never follow through).

17. ### DywyddyrPenguinaciously duckalicious.Valued Senior Member

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18,754
Still wrong: if the rocket exhaust is at the bottom then that's where the thrust is applied.
So even with your "free moving rocket" the "force will be from the bottom".

18. ### billvonValued Senior Member

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14,528
So put a long stick up your rocket, mount the engine to the end of that and then get rid of the magnet. That way the force is transferred to the top (which is important to you for some reason) and you don't need the heavy magnets.

19. ### KittamaruSuppose it makes sense. Wearing a bit thin.Valued Senior Member

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13,937
Oooh, I have an even better idea! Instead of a long stick (which would suffer from torsion effects and bending), why not make it a long tube attached to the engine and running to the front of the rocket? Then, you could even store stuff inside the tube! And attach things to it! You could even make the tube wider to accommodate more engines or more fuel and more cargo!

20. ### Rocket PaulRegistered Member

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56
Dywyddyr I don't think I have said that the initial thrust is not coming from the back but with the pipe test we are lifting the pipe from the front so action and reaction to the hand or engine with no reaction to the craft but equal action and reaction applied we have the result of the test.

billvon If you do the pipe test I suggest then you will see for yourself why force at the top is so important you can see for yourself the balance of the craft is so much better than thrusting from the bottom, but like you say it can work without the magnets just a straight poke force to the top would work or use a spring instead of magnets, but remember why I suggested using magnets in the first place its to cushion the inner engine from slamming in to the craft.

Kittamaru yes there are 100s of modifications that could be done but for now just trying to get the basic understandings realized, to give some ideas if the system is ever built then we can make a much smaller rockets we could have flying cars we could lift most shapes in to orbit and much much more but please I am not going in to details I just cant take the flack.

21. ### SarkusHippomonstrosesquippedalo phobeValued Senior Member

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WTF? Am I missing something here? Where is the improved efficiency coming from? Why will it suddenly be easier to lift things into orbit, or allow for flying cars??
Unfortunately, reading through the posts, it seems that you lack a basic grounding in applied mathematics and physics.

But let's break it down to a few simple questions:
1. In a conventional rocket, the force applied from the bottom (F) acts on the mass of the total object (M) resulting in an acceleration (a). The physics is F = Ma. Okay so far?
Okay, so, in your rocket design, do you think that the force applied to the mass results in something different? If so, what?

2. Do you think the engine suddenly gets more efficient that it can produce force F for the same time but using less fuel? If so, how does your design manage to do that when to lift the same mass, the efficiency is a function of the engine, not the design - at least until the aerodynamic effect kicks in.

3. If you say no to both 1 and 2, then wtf are you actually going on about?

22. ### Rocket PaulRegistered Member

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56
That's all I am saying is if the rocket is more balanced by lifting it up from the top then you can escape earths gravity at a much slower speed, same mass same engine but lifting from the top instead of the bottom.

23. ### SarkusHippomonstrosesquippedalo phobeValued Senior Member

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7,854
How does balance effect the speed you need to escape earth's velocity?? Someone has already pointed out that to escape earth's gravity you need to travel above a certain speed (11.2 km/s) and it has nothing to do with balance.

So, please, how does an improved balance lead to being able to "escape earths gravity at a much slower speed"? Have you done the actual maths?
If there are improvements in balance to be had then I can see that there might be efficiency improvements, from not having to perform small adjustments, but the fuel needed for such is already a tiny fraction of the overall rocket mass in a well-designed rocket.

So what sort of improvement do you envisage this design of yours giving, if all it does (if what you say is correct, and just a word to the wise: you're not) is improve stability?
Also, assuming that the thrust is through the line of symmetry of the rocket, you do know that the stability is more to do with the centre of gravity and centre of pressure, and overall aerodynamic design rather than whether the engine is attached to the top or bottom?