Instead of beating around the bush, why not make/buy a vacuum chamber and test your hypothesis yourself?
Hoppy is correct, the equal and opposite reaction theory given for rockets does not make sense.Actually, it does if you understand where the action/reaction pairings are occurring (primarily within the combustion chamber).
Rockets work just fine in space, it's just simply conservation of momentum.
http://www.discovery.com/tv-shows/mythbusters/videos/its-rocket-science/
Instead of beating around the bush, why not make/buy a vacuum chamber and test your hypothesis yourself?Perhaps this can be an activity the society can fundraise for.
Instead of beating around the bush, why not make/buy a vacuum chamber and test your hypothesis yourself?Perhaps this can be an activity the society can fundraise for.
That's obviously never, ever going to happen.
Instead of making pie-in-the-sky plans that will never come to fruition, why not just spend the money to test your hypothesis on your own? We're only talking about a few hundred bucks here; maybe a grand if you wanted to build something pretty nice. Maybe front the money for the equipment, conduct the experiment, make a detailed recording of your expenses, and then try to raise funds to cover those costs. I would genuinely be happy to throw a few bucks your way to offset the cost of such an experiment so long as it was well-documented. I imagine others would as well.
My point is that you probably already have the means to test your hypothesis and record your results here. Why merely take the word of a YouTube video?
I would like to see one more experiment tried, with a barrier that is not attached to the vehicle. For instance, what would happen if he put his outstretched palm following the exhaust pipe at a distance of two inches as the car sped away? Would the car speed up since his hand is more solid than the atmosphere? I think that might be more conclusive evidence.
Since air is essentially invisible to the naked eye, it can pretty hard to follow exactly what's going on. I would suggest filling the balloon with smoke and recording the various tests (hand right next to exhaust, 1 inch away, 2 inches, etc.) in slow motion (many new camera phones have this ability). My guess is that there would be a certain amount of exhaust "bouncing" off the hand and interacting with the car for a second time. However, I suspect that this "pogo" effect would drop off quickly as you move your hand further away. Still, it might be interesting to test.I would like to see one more experiment tried, with a barrier that is not attached to the vehicle. For instance, what would happen if he put his outstretched palm following the exhaust pipe at a distance of two inches as the car sped away? Would the car speed up since his hand is more solid than the atmosphere? I think that might be more conclusive evidence.Do you have any comments on the validity of such an experiment?
That box is not a true vacuum, I saw a vid on the other site where near vacuum pressure inplodes a steel railroad tanker car. It just folded up like an accordian. There is no way that plexi box was a vacuum.Rockets work just fine in space, it's just simply conservation of momentum.
http://www.discovery.com/tv-shows/mythbusters/videos/its-rocket-science/
Thank you for that link. I agree that it appears that the rocket did work in a vacuum. However, on reassessment of the idea, I do not think a relatively small vaccum chamber would be an appropriate test of this theory.
The author of the video would assert that rather that, rather than the atmosphere, the bottle rocket is pushing off of the pixiglass door behind the rocket in this experiment, and his theory holds.
That box is not a true vacuum, I saw a vid on the other site where near vacuum pressure inplodes a steel railroad tanker car. It just folded up like an accordian. There is no way that plexi box was a vacuum.Railroad tanker cars are designed to resist the forces of their contents pressing outwards, not necessarily forces from the outside pressing inwards.
Irrelevant. What is a home made plexiglass box designed for?That box is not a true vacuum, I saw a vid on the other site where near vacuum pressure inplodes a steel railroad tanker car. It just folded up like an accordian. There is no way that plexi box was a vacuum.Railroad tanker cars are designed to resist the forces of their contents pressing outwards, not necessarily forces from the outside pressing inwards.
Then why did you bring it up?Irrelevant.That box is not a true vacuum, I saw a vid on the other site where near vacuum pressure inplodes a steel railroad tanker car. It just folded up like an accordian. There is no way that plexi box was a vacuum.Railroad tanker cars are designed to resist the forces of their contents pressing outwards, not necessarily forces from the outside pressing inwards.
What is a home made plexiglass box designed for?That would depend on who designed it and why.
Upon some reflection on the theory as stated in the video, I no longer believe that a small vacuum chamber can test this effect. It can be argued by proponents of the theory that the craft is pushing off of a wall of the chamber, rather than the atmosphere, and that nothing would be demonstrated either way.
I would like to see one more experiment tried, with a barrier that is not attached to the vehicle. For instance, what would happen if he put his outstretched palm following the exhaust pipe at a distance of two inches as the car sped away? Would the car speed up since his hand is more solid than the atmosphere? I think that might be more conclusive evidence.
Do you have any comments on the validity of such an experiment?
I think this explanation still requires Newton's Third Law as a premise; it merely moves the discussion of action-reaction pairs from rockets and exhaust particles, to exhaust particles and walls. If we're talking about exhaust "pushing" the rocket off of a wall, then we're still talking about Newton's Third. The rocket pushes on the wall, and the wall pushes back. But if Newton's Third Law is correct, then thrust is perfectly understandable via the action-reaction pair of exhaust particles and the rocket that accelerated them. Exhaust particles cannot be accelerated out of the nozzle without the application of a force, and the application of that force must correspond to a force of equal magnitude in the opposite direction.
It's also not clear to me, contrary to Newton's explanation of thrust, how the process of pushing off the wall in this manner works. A particle leaves the nozzle and collides with a wall. Then what? How does the particle of exhaust hitting a wall accelerate the vehicle it just left behind?
Exhaust particles cannot be accelerated out of the nozzle without the application of a force, and the application of that force must correspond to a force of equal magnitude in the opposite direction.
Why must the exhaust of particles correspond to a force of equal magnitude in empty space? That does not make any sense. What makes sense is if the particles are hitting something, pushing the entire vehicle system, exhaust and all, forward.
The exhaust is a high pressure fluid. It is connected to the vehicle. As the exhaust encounters resistance, that resistance will trickle back to the vehicle.
It's like one of those water jetpacks. The jetpack does not rise in altitude until the water has hit the surface. The high pressured water is connected to the jetpack as a single entity. Resistance on the water results resistance on the jetpack. The tension ripples upwards through the whole entity.
In that photo the tension/resistance is rippling up the water stream in waves at the speed of sound. Imagine if we had a string stretched taught for 3000 miles across the USA, between California and New York. If we pull the string in California, will New York feel it instantly? No, it takes time for the message to be communicated.
In the jetpack photo there are trillions of streams of water in communication with the surface and resistance of the air. Some parts may not have a constant connection, and some may be disconnected below at some points, but the water is rushing so fast and in such quantity that there is always some kind of communication of resistance communicated to the wearer. A small gap in the water means only that the wearer will dip a little once that gap of resistance is communicated up to the jetpack.
I think this could be a subject worth further investigation. I would like to see one more experiment tried, with a barrier that is not attached to the vehicle. For instance, what would happen if he put his outstretched palm following the exhaust pipe at a distance of two inches as the car sped away? Would the car speed up since his hand is more solid than the atmosphere? I think that might be more conclusive evidence.Note how much force is pushing back against your hand while operating a garden hose nozzle. Now place that same nozzle in a bucket of water. Does the force increase or decrease?
Are there any other ways which can prove or disprove his theory which seems to suggest that Newton's Third Law is false?
The exhaust is a high pressure fluid. It is connected to the vehicle. As the exhaust encounters resistance, that resistance will trickle back to the vehicle.
It's like one of those water jetpacks. The jetpack does not rise in altitude until the water has hit the surface. The high pressured water is connected to the jetpack as a single entity. Resistance on the water results resistance on the jetpack. The tension ripples upwards through the whole entity.
I think this could be a subject worth further investigation. I would like to see one more experiment tried, with a barrier that is not attached to the vehicle. For instance, what would happen if he put his outstretched palm following the exhaust pipe at a distance of two inches as the car sped away? Would the car speed up since his hand is more solid than the atmosphere? I think that might be more conclusive evidence.Note how much force is pushing back against your hand while operating a garden hose nozzle. Now place that same nozzle in a bucket of water. Does the force increase or decrease?
Are there any other ways which can prove or disprove his theory which seems to suggest that Newton's Third Law is false?
In that photo the tension/resistance is rippling up the water stream in waves at the speed of sound. Imagine if we had a string stretched taught for 3000 miles across the USA, between California and New York. If we pull the string in California, will New York feel it instantly? No, it takes time for the message to be communicated.
In the jetpack photo there are trillions of streams of water in communication with the surface and resistance of the air. Some parts may not have a constant connection, and some may be disconnected below at some points, but the water is rushing so fast and in such quantity that there is always some kind of communication of resistance communicated to the wearer. A small gap in the water means only that the wearer will dip a little once that gap of resistance is communicated up to the jetpack.
The exhaust is NOT a high pressure fluidActually, it is. In physics, both gasses and liquids are considered to be fluids (along with plasma and plastic solids, to some extent). So rapidly expanding, hot exhaust gasses are, indeed, fluid in nature.
The fuel is 2 compressed fluids, where one is an oxidizer.Close, but not quite. In liquid fuel rockets, the fuel and oxidizer are (as the name suggests) liquids being fed under pressure. Unlike gasses, most liquids don't compress very well.
The exhaust is NOT a high pressure fluidActually, it is. In physics, both gasses and liquids are considered to be fluids (along with plasma and plastic solids, to some extent). So rapidly expanding, hot exhaust gasses are, indeed, fluid in nature.The fuel is 2 compressed fluids, where one is an oxidizer.Close, but not quite. In liquid fuel rockets, the fuel and oxidizer are (as the name suggests) liquids being fed under pressure. Unlike gasses, most liquids don't compress very well.
i/no-one's ever been up there to prove they do!
ii/they could never penetrate through the upper layers of the thermo-sphere any-way
iii/they won't work in a vacuum ......and there's no real proof that they can
(assuming, of course, that the very upper regions of 'the atmosphere' are a vacuum, as such....again....no-one's been up that high)