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Does Rocketry Work beyond Earth's atmosphere?
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simonshack
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Re: Does Rocketry Work in the Vacuum?
Topics Of the Times
I found this interesting piece and transcribed it below.
http://graphics8.nytimes.com/packages/p ... l-full.pdf
It's an editorial from New York Times anno 1920. I found it through this article:
http://www.popsci.com/military-aviation ... work-space
And as the author (whom seems to sadly be unknown) points out - To claim that rockets can work in the vacuum of space would be "to deny a fundamental law of dynamics, and only Dr. EINSTEIN and his chosen dozen, so few and fit, are licensed to do that."
TOPICS OF THE TIMES (New York Times, Jan 13, 1920)
A Severe Strain on Credulity
As a method of sending missile to the higher, and even to the highest, part of the earth's atmosphere envelope, Professor GODDARD'S multiple-charge rocket is a practicable, and therefore promising, device. Such a rocket, too, might carry self-recording instruments, to be released at the limit of its flight, and conceivably parachutes would bring them safely to the ground. It is not obvious, however, that the instruments would return to the point of departure; indeed, it is obvious that they would not, for parachutes drift exactly as balloons do. And the rocket, or what was left of it after the last explosion, would have to be aimed with amazing skill, and in a dead calm, to fall on the spot where it started.
But that is a slight inconvenience, at least from the scientific standpoint, though it might be serious enough from that of the always innocent bystander a few hundred or thousand yards away from the firing line. It is when one considers the multiple-charge rocket as a traveler to the moon that one begins to doubt and looks again, to see if the dispatch announcing the professor's purposes and hopes says that he is working under the auspices of the Smithsonian Institution. It does say so, and therefore the impulse to do more than doubt the practicability of such a device for such a purpose must be-well, controlled. Still, to be filled with uneasy wonder and to express it will be safe enough, for after the rocket quits our air and really starts on its longer journey, its flight would be neither accelerated nor maintained by the explosion of the charges it then might have left. To claim that it would be is to deny a fundamental law of dynamics, and only Dr. EINSTEIN and his chosen dozen, so few and fit, are licensed to do that.
His plan is not original.
That Professor GODDARD, with his "chair" in Clark College and the countenancing of the Smithsonian Institution does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react-to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.
But there are such things as intentional mistakes or oversights, and, as it happens, JULES VERNE, who also knew a thing or two in assorted sciences-and had, besides, a surprising amount of prophetic power-deliberately seemed to make the same mistake that Professor GODDARD seems to make. For the Frenchman, having got his travelers to or toward the moon into the desperate fix of riding a tiny satellite of the satellite, saved them from circling it forever by means of an explosion would not have had in the slightest degree the effect of releasing them from their dreadful slavery. That was one of VERNE'S few scientific slips, or else it was a deliberate step aside from scientific accuracy, pardonable enough in him as a romancer, but its like is not so explained when made by a savant who isn't writing a novel of adventure.
All the same, if Professor GODDARD'S rocket attains sufficient speed before it passes out of our atmosphere-which is a thinkable possibility-and if its aiming takes into account all of the many deflective forces that will affect its flight, it may reach the moon. That the rocket could carry enough explosive to make on impact a flash large and bright enough to be seen from the earth by the biggest of our telescopes-that will be believed when it is done.
I found this interesting piece and transcribed it below.
http://graphics8.nytimes.com/packages/p ... l-full.pdf
It's an editorial from New York Times anno 1920. I found it through this article:
http://www.popsci.com/military-aviation ... work-space
And as the author (whom seems to sadly be unknown) points out - To claim that rockets can work in the vacuum of space would be "to deny a fundamental law of dynamics, and only Dr. EINSTEIN and his chosen dozen, so few and fit, are licensed to do that."
TOPICS OF THE TIMES (New York Times, Jan 13, 1920)
A Severe Strain on Credulity
As a method of sending missile to the higher, and even to the highest, part of the earth's atmosphere envelope, Professor GODDARD'S multiple-charge rocket is a practicable, and therefore promising, device. Such a rocket, too, might carry self-recording instruments, to be released at the limit of its flight, and conceivably parachutes would bring them safely to the ground. It is not obvious, however, that the instruments would return to the point of departure; indeed, it is obvious that they would not, for parachutes drift exactly as balloons do. And the rocket, or what was left of it after the last explosion, would have to be aimed with amazing skill, and in a dead calm, to fall on the spot where it started.
But that is a slight inconvenience, at least from the scientific standpoint, though it might be serious enough from that of the always innocent bystander a few hundred or thousand yards away from the firing line. It is when one considers the multiple-charge rocket as a traveler to the moon that one begins to doubt and looks again, to see if the dispatch announcing the professor's purposes and hopes says that he is working under the auspices of the Smithsonian Institution. It does say so, and therefore the impulse to do more than doubt the practicability of such a device for such a purpose must be-well, controlled. Still, to be filled with uneasy wonder and to express it will be safe enough, for after the rocket quits our air and really starts on its longer journey, its flight would be neither accelerated nor maintained by the explosion of the charges it then might have left. To claim that it would be is to deny a fundamental law of dynamics, and only Dr. EINSTEIN and his chosen dozen, so few and fit, are licensed to do that.
His plan is not original.
That Professor GODDARD, with his "chair" in Clark College and the countenancing of the Smithsonian Institution does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react-to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.
But there are such things as intentional mistakes or oversights, and, as it happens, JULES VERNE, who also knew a thing or two in assorted sciences-and had, besides, a surprising amount of prophetic power-deliberately seemed to make the same mistake that Professor GODDARD seems to make. For the Frenchman, having got his travelers to or toward the moon into the desperate fix of riding a tiny satellite of the satellite, saved them from circling it forever by means of an explosion would not have had in the slightest degree the effect of releasing them from their dreadful slavery. That was one of VERNE'S few scientific slips, or else it was a deliberate step aside from scientific accuracy, pardonable enough in him as a romancer, but its like is not so explained when made by a savant who isn't writing a novel of adventure.
All the same, if Professor GODDARD'S rocket attains sufficient speed before it passes out of our atmosphere-which is a thinkable possibility-and if its aiming takes into account all of the many deflective forces that will affect its flight, it may reach the moon. That the rocket could carry enough explosive to make on impact a flash large and bright enough to be seen from the earth by the biggest of our telescopes-that will be believed when it is done.
Re: Does Rocketry Work in the Vacuum?
While reading the above, I imagined getting one of those toy rockets and making it heavy enough to slow it down like the real NASA rockets. Without even needing to try it, I am positive it would fall over, probably no matter how well I tried to balance it.hoi.polloi » July 7th, 2017, 5:03 pm wrote:Another funny thing about those rockets I used to play with as a teenager (I think they were called "Estes") is that they would accelerate instantly, like an explosion. I know this has already been covered in previous discussions, but I find this important to mention and/or "bump" it because I think it's a pretty critical discussion when we are watching these towering, slow-moving objects barely climb into the air on the launch videos.
While writing the above, I started wondering if there are any rocket design contests for college engineering programs. The following one from MIT includes a video: http://rocketry.mit.edu/2015/05/launch/. The first thing I noticed about the video was how far away they filmed it. IDK, maybe it was for safety reasons, but seems a little fishy. I would want to see it close up. I also noticed how fast the rocket accelerated at first, but then it slowed down. Again, to give them the benefit of the doubt, maybe they had a multi-stage thruster and the first one was the strongest.
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hoi.polloi
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Re: Does Rocketry Work in the Vacuum?
These are important discussions to have!
Remember, next on "The Clues Chronicle" we will be discussing this very thread and the topics covered, so please let us know what you'd like K and I to tell people. What are the most critical points, for example? What are the weakest? How can we convey this over audio? Any and all suggestions welcome!
Remember, next on "The Clues Chronicle" we will be discussing this very thread and the topics covered, so please let us know what you'd like K and I to tell people. What are the most critical points, for example? What are the weakest? How can we convey this over audio? Any and all suggestions welcome!
Re: Does Rocketry Work in the Vacuum?
To preface my comments, I'm convinced that rocketry theoretically works in a vacuum, but they haven't yet solved the tremendous technical challenges. That doesn't seem to matter because in order to keep the money flowing, they only need to fake it.hoi.polloi » September 23rd, 2017, 7:14 pm wrote: Remember, next on "The Clues Chronicle" we will be discussing this very thread and the topics covered, so please let us know what you'd like K and I to tell people. What are the most critical points, for example? What are the weakest? How can we convey this over audio? Any and all suggestions welcome!
In the next episode, I'd be interested to hear your thoughts about how the world would be different if all this stuff worked as claimed. Over the several decades of rocketry, it should be so advanced and cheaper that we'd have space ships up there already and tons of video showing it. There'd be video of student projects in space, or different companies competing with each other for the best rocket thruster design. The lack of all this activity is a giant clue that thrust doesn't work well enough yet.
I'm also interested in how the spent rocket thrusters always seem to fall back to Earth, even after delivering their satellite payloads. With all the kinetic energy used to put the rocket and satellites into space, the rockets would most likely end up in some kind of orbit that might last a long time before they happened to get caught by the atmosphere.
As some feedback, I really like the episodes and listen to them multiple times while traveling. I don't mind at all when you start discussing peripheral topics. Although I enjoy the philosophical side of things, you could spend a little more time discussing the technical issues, like all the theories of why rocketry should not work in a vacuum.
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simonshack
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Re: Does Rocketry Work in the Vacuum?
You have me totally riveted to my seat, dear molodyets! Will you please explain to me (in graspable manner) just how rocketry would theoretically work in the airless void of space? I really wish to understand. Since you claim to be 'convinced' that it works, I'm sure you can share with us all this conviction of yours.molodyets » September 24th, 2017, 4:52 pm wrote: To preface my comments, I'm convinced that rocketry theoretically works in a vacuum, but they haven't yet solved the tremendous technical challenges.
Re: Does Rocketry Work in the Vacuum?
Ah, my favorite subject coming up :-) The reason being that if you "get this", then it becomes clear that nothing can enter space since there are no known transportation systems to put things there.hoi.polloi » September 23rd, 2017, 7:14 pm wrote:These are important discussions to have!
Remember, next on "The Clues Chronicle" we will be discussing this very thread and the topics covered, so please let us know what you'd like K and I to tell people. What are the most critical points, for example? What are the weakest? How can we convey this over audio? Any and all suggestions welcome!
But as Cluesforum readers may know, this was the hardest part for me to understand. I came to this forum with blazing cannons about how satellites and rockets could not be fake. It was with good intentions however since I was convinced about all your other research but believed this to be disinformation along the lines of Flat Earth.
So how does a mind like mine work and how can we "deprogram" it assuming that is a goal with the show? I came to the point where Anders Björkman and Paul Clark was pretty soon. Being that re-entry is not possible thus making satellites and space probes possible, but not manned space ships. But then my progression halted. I think one reason is that the satellite and rocket hoax is indirectly enforced through the many theories surrounding the Moon hoax. So when you "accept" the Moon hoax you are also accepting that they faked it by going to low earth orbit or by having a satellite that simulated the communication between the Moon rocket and earth. And then there are of course the GPS and Satellite TV stories.
As for evidence I would say the Joule-Thomson experiment performed in the late 19th century seals the fate for rockets in an unrestricted vacuum, and it is quite possible to perform a more visually appealing experiment. A small rocket or bottle with compressed gas in a sufficiently large vacuum chamber would not be able to react against the wall of the chamber or pressurize the chamber enough to react with the gas it itself produces. But it seems that Youtube is kept clean of videos that do not perform this experiment in a deceptive manner where the chamber is too small and/or the rocket can react against the wall of the chamber.
I would say that "Rockets in vacuum" is one of the Nutworks "finest" accomplishments. Their goal is to make us choose their fantasies and stories in favor of what we actually can observe and understand with our own senses and intellect. This is what gives these psychos a mental orgasm and makes them feel in control. And boy have they succeeded with the rocket hoax. The physical laws that makes rocketry in vacuum impossible is simple and verifiable by controlled experiments. But through their control of media and persistence they have made the entire world deny the objective reality in favor of their fantasy. And that included a grown up and reasonably intelligent man like me until recently.
So Thank You Simon, Hoi and all the other fine researchers here at Cluesforum for giving me back my reality. Let's keep it real together.
Have a great show Hoi and Kham! I'm looking forward to listen to it and I hope these rocket musings gave you some food for thought.
Last edited by patrix on Mon Sep 25, 2017 11:41 am, edited 1 time in total.
Re: Does Rocketry Work in the Vacuum?
Yes, that statement is elementary physics, but do you have any proof that this is actually happening in the real world, and not in the mathematical fantasy world of physicists, like black holes, apart from the silly images we see on tv? Otherwise, your sentence is one of the silliest sentences I have read in this forum!molodyets » 24 Sep 2017, 18:52 wrote:With all the kinetic energy used to put the rocket and satellites into space, the rockets would most likely end up in some kind of orbit that might last a long time before they happened to get caught by the atmosphere.
Re: Does Rocketry Work in the Vacuum?
Maybe you forgot the context of my comment? I was giving my suggestion to Hoi, at his request, about what to include in his next podcast. I think that is a very good example of how NASA's claims are totally inconsistent.agraposo » September 25th, 2017, 11:00 am wrote:Yes, that statement is elementary physics, but do you have any proof that this is actually happening in the real world, and not in the mathematical fantasy world of physicists, like black holes, apart from the silly images we see on tv? Otherwise, your sentence is one of the silliest sentences I have read in this forum!molodyets » 24 Sep 2017, 18:52 wrote:With all the kinetic energy used to put the rocket and satellites into space, the rockets would most likely end up in some kind of orbit that might last a long time before they happened to get caught by the atmosphere.
Simon asked 'very sarcastically' about the reason why I think rocketry can work in a vacuum. I think maybe we have a different definition of terms. When I write rocketry, I mean the cause of thrust. At the present, I agree with the mainstream thought that for a closed system (rocket components + fuel), when the byproducts of combustion are ejected away from the rocket, that momentum is conserved and this is interpreted as thrust for the rocket. If momentum is not conserved in the vacuum, I would be very interested to learn that. This is why I asked Hoi to go into more detail about how rocketry cannot work in a vacuum. So let me return to the definition of terms. On this forum, rocketry probably means moving rockets into space. I am in total agreement that NASA and other agencies are obviously faking that because it cannot be done.
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antipodean
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Re: Does Rocketry Work in the Vacuum?
Looking forward to it. Correct me if I'm wrong but we can look forward to some of Newton's laws of gravity being questioned. As I once tried to in this post.hoi.polloi » September 24th, 2017, 6:14 am wrote:These are important discussions to have!
Remember, next on "The Clues Chronicle" we will be discussing this very thread and the topics covered, so please let us know what you'd like K and I to tell people. What are the most critical points, for example? What are the weakest? How can we convey this over audio? Any and all suggestions welcome!
http://cluesforum.info/viewtopic.php?p=2364714#p2364714
One of the weapons used by the Moon Landing huggers is the interpretation of Newton's laws.
Space being a vacuum, objects entering space being continually powered by the effects of being in a vacuum. Until they reach the gravitational pull of another celestial body. (the moon)
How could someone in the 18th Century be an expert on the atmospheric conditions of space ?
Also what about the intermediate area between the Earth's atmosphere and Space itself. Or is that explained by being the Van Allen belt ?
Or maybe I'm thick and just can't grasp it. Looking forward to Kham explain why I was a dunce at Physics.
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The_White_Lodge
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On the Feasibility of Rocketry in a Vacuum and Atmosphere
I have read through a good portion of this thread and I would like to clear up a few technical points which continue to get confused regarding rockets.
First, I would like to state my current position regarding the existence of satellites and other space technologies.
I do not believe that there are orbiting satellites. I have however, seen many "iridium flares," which I call floaters, with my own eyes, and having observed them to the extent I have, I find it impossible to believe this phenomenon has been occurring throughout history considering that there is no accounting of it going back even as far as the 1930's that I am aware of. Therefore, I do believe that these floaters, are man-made objects, though I doubt they are "in orbit" and I am confident that their design is not as satellites supposedly are. I hope to eventually discuss my theories regarding what kind of object they actually are, but for now I will leave it at that.
I am also firmly convinced, that every application which is attributed to satellites, such as broadcast television, and gps are actually carried out through ground based technologies. In every case, the ground based option would make more sense from a business and technical point of view, and in most cases even if orbiting satellites were practically possible, the supposed applications attributed to them would not be.
Okay, now onto the analysis of rocketry:
Let us first consider the scenario of a rocket in a vacuum discounting all other practical considerations besides the physical mechanics of propulsion and thrust. Is the proposed mechanism viable? There is no denying under Newton's three laws of motion, in this entirely theoretic scenario that it is. The mechanism is this: there is an explosion of propellent within a chamber which produces force in all directions, in theory all these forces would cancel out except those which are pointing along the opposite vector of the chamber's opening. Along this vector there would be a positive force and so the rocket would move along this vector. It is the same mechanism as the recoil that occurs when a bullet is fired out of a gun. It has nothing to do with propellent pushing against air. The medium which the propellent is exiting into is irrelevant with regards to the most fundamental mechanics.
Now, if there is anyone out there who just felt a spark of hope that their science fiction fantasies may be real, unfortunately, that is where any sensibility in the design of rockets in space or the upper atmosphere comes to an end. For the second we begin to consider any practical reality beyond this fundamental mechanism of motion we will find that there are endless problems and reasons why the design of a rocket launching into space cannot work.
First, let us consider the most basic of these problems regarding a vacuum, that being, the lack of oxygen necessary to sustain combustion. In a vacuum, there is no oxygen, but combustion requires oxygen, consider for example, what happens when you put a glass seal over a burning flame. Now, the claimed work-around for this fact is that rocket fuel is claimed to be:
To understand why this is a case, consider a basic law of pressure: when there is a pressure differential between the interior and exterior of a chamber, to reduce the exterior on the pressure of the chamber has the same effect as increasing the internal pressure of the chamber. Now, if these rocket fuel tanks are already highly pressurized to begin with on the surface of the Earth, how can these fuel tanks maintain functionality through radical change of external pressure, which are not claimed to be happening gradually I might add, but rapidly. The answer is that, they cannot, and were such a design practically implemented, the fuel tanks would explode due to the rapid drop in pressure before even reaching the upper atmosphere.
Furthermore, even if the tanks could somehow be designed to avoid exploding, the controlled release of their gases would become impossible, since as the external pressure decreases the force and velocity of gas exiting the tank would rapidly increase in the same way that to a tire can be deflated with control if there is a small hole, but if there is a large gash it's deflation cannot be controlled. This is especially damning to the space rocket design because the design is so dependent on near perfect control of fuel expenditure.
Were someone to suggest that rockets could be made to accelerate more gradually, I would say, the more gradually they would accelerate the more possible it would be to implement a design feature in the fuel tanks which could compensate the change in pressure.
If we were to add more layers of reality into this analysis then we would find many more problems and inconsistencies with the rocket narrative, but I would like to leave at this for now and to summarize.
The mechanism of a rocket moving in a vacuum on the basis of purely theoretic consideration of fundamental laws of motion is viable, but when considering additional practical realities such as external changes in pressure and the functionality of a pressurized fuel tank with near zero external pressure it becomes clear that the design would not be viable.
I have read through a good portion of this thread and I would like to clear up a few technical points which continue to get confused regarding rockets.
First, I would like to state my current position regarding the existence of satellites and other space technologies.
I do not believe that there are orbiting satellites. I have however, seen many "iridium flares," which I call floaters, with my own eyes, and having observed them to the extent I have, I find it impossible to believe this phenomenon has been occurring throughout history considering that there is no accounting of it going back even as far as the 1930's that I am aware of. Therefore, I do believe that these floaters, are man-made objects, though I doubt they are "in orbit" and I am confident that their design is not as satellites supposedly are. I hope to eventually discuss my theories regarding what kind of object they actually are, but for now I will leave it at that.
I am also firmly convinced, that every application which is attributed to satellites, such as broadcast television, and gps are actually carried out through ground based technologies. In every case, the ground based option would make more sense from a business and technical point of view, and in most cases even if orbiting satellites were practically possible, the supposed applications attributed to them would not be.
Okay, now onto the analysis of rocketry:
Let us first consider the scenario of a rocket in a vacuum discounting all other practical considerations besides the physical mechanics of propulsion and thrust. Is the proposed mechanism viable? There is no denying under Newton's three laws of motion, in this entirely theoretic scenario that it is. The mechanism is this: there is an explosion of propellent within a chamber which produces force in all directions, in theory all these forces would cancel out except those which are pointing along the opposite vector of the chamber's opening. Along this vector there would be a positive force and so the rocket would move along this vector. It is the same mechanism as the recoil that occurs when a bullet is fired out of a gun. It has nothing to do with propellent pushing against air. The medium which the propellent is exiting into is irrelevant with regards to the most fundamental mechanics.
Now, if there is anyone out there who just felt a spark of hope that their science fiction fantasies may be real, unfortunately, that is where any sensibility in the design of rockets in space or the upper atmosphere comes to an end. For the second we begin to consider any practical reality beyond this fundamental mechanism of motion we will find that there are endless problems and reasons why the design of a rocket launching into space cannot work.
First, let us consider the most basic of these problems regarding a vacuum, that being, the lack of oxygen necessary to sustain combustion. In a vacuum, there is no oxygen, but combustion requires oxygen, consider for example, what happens when you put a glass seal over a burning flame. Now, the claimed work-around for this fact is that rocket fuel is claimed to be:
Now, I do not know enough about liquid oxygen to suggest that it would be impossible to create such a fuel, although the very idea of such a fuel strikes me as odd, but I will give this claim the benefit of the doubt that such a fuel exists and can be made useful for it's claimed purposes. However, even if such a fuel exists, it would not be possible to store it or utilize it when moving from the external pressures of conditions on the surface of Earth to a vacuum with near zero external pressure.either a high oxygen containing fuel or a mixture of fuel plus oxidant, whose combustion takes place, in a definite and controlled manner with the evolution of a huge volume of gas
To understand why this is a case, consider a basic law of pressure: when there is a pressure differential between the interior and exterior of a chamber, to reduce the exterior on the pressure of the chamber has the same effect as increasing the internal pressure of the chamber. Now, if these rocket fuel tanks are already highly pressurized to begin with on the surface of the Earth, how can these fuel tanks maintain functionality through radical change of external pressure, which are not claimed to be happening gradually I might add, but rapidly. The answer is that, they cannot, and were such a design practically implemented, the fuel tanks would explode due to the rapid drop in pressure before even reaching the upper atmosphere.
Furthermore, even if the tanks could somehow be designed to avoid exploding, the controlled release of their gases would become impossible, since as the external pressure decreases the force and velocity of gas exiting the tank would rapidly increase in the same way that to a tire can be deflated with control if there is a small hole, but if there is a large gash it's deflation cannot be controlled. This is especially damning to the space rocket design because the design is so dependent on near perfect control of fuel expenditure.
Were someone to suggest that rockets could be made to accelerate more gradually, I would say, the more gradually they would accelerate the more possible it would be to implement a design feature in the fuel tanks which could compensate the change in pressure.
If we were to add more layers of reality into this analysis then we would find many more problems and inconsistencies with the rocket narrative, but I would like to leave at this for now and to summarize.
The mechanism of a rocket moving in a vacuum on the basis of purely theoretic consideration of fundamental laws of motion is viable, but when considering additional practical realities such as external changes in pressure and the functionality of a pressurized fuel tank with near zero external pressure it becomes clear that the design would not be viable.
Yes there is, and it's been proven beyond reasonable doubt by controlled experiments. Newton physics are fine but they are not applicable to this. Rocket fuel changing into gas and heat is a chemical reaction, and the molecules in that reaction cannot act upon themselves in some Newtonian way. Think about the situation visually. The molecules in the rocket fuel is starting to move more and bounce around in the rocket nozzle. Some bounce on the sides, some on the front and some drift merrily away into the vacuum. How could the fact that some drift out the back without having any way to interact with each other create a pressure difference within the rocket that makes it move? If there was enough molecules outside the rocket, the situation would be different because then some molecules would bounce back creating said pressure difference.There is no denying under Newton's three laws of motion, in this entirely theoretic scenario that it is.
I think it has been mentioned in this thread or in some one related, but it seems that free expansion of gases cannot produce any work, in physical sense. There is a pretty good discussion here: https://www.physicsforums.com/threads/w ... um.725702/
So, the idea is that work is done by pressure. In an atmosphere, the gas ejected from the rockets would build a pressure gradient, from a maximum near the exhaust, and gradually decreasing until it levels off with atmospheric pressure. So, it's the pressure buildup what pushes the rocket upwards. A nice way to model this would be to imagine a compressed air cilinder and then opening the valve.
But in a vacuum, the gradient 'endpoint' would be 0, so the gas molecules would have no opposing force when moving away from the rocket.
In fact, it's strange that I've found no literature about such a simple experiment as would be opening the valve of a compressed air cilinder in a vacuum chamber and measuring the resulting forces. And then comparing it with the same experiment in the atmosphere. My guess is that the exerted force would be almost negligible, but maybe non-zero.
So, the idea is that work is done by pressure. In an atmosphere, the gas ejected from the rockets would build a pressure gradient, from a maximum near the exhaust, and gradually decreasing until it levels off with atmospheric pressure. So, it's the pressure buildup what pushes the rocket upwards. A nice way to model this would be to imagine a compressed air cilinder and then opening the valve.
But in a vacuum, the gradient 'endpoint' would be 0, so the gas molecules would have no opposing force when moving away from the rocket.
In fact, it's strange that I've found no literature about such a simple experiment as would be opening the valve of a compressed air cilinder in a vacuum chamber and measuring the resulting forces. And then comparing it with the same experiment in the atmosphere. My guess is that the exerted force would be almost negligible, but maybe non-zero.
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The_White_Lodge
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Patrix,
You bring up a good point, however this point contests gas laws in a vacuum, not mechanical laws. The mechanical principles which I outlined still apply, whether the gases in question would function as theoretical suggested is another matter.
Your intuition on this I believe is accurate, but it is expressed in a way which is unclear. If a controlled explosion could occur in a vacuum, then the expected motion would uphold. But, it doesn't make much sense to suggest a controlled explosion caused by a chemical reaction could be managed in a vacuum, because as you suggest there is no external pressure to ensure that two given substances mix and interact, were they somehow released from a tank into a chamber they would likely be rapidly sucked towards the low pressure opening of the chamber without ever having a chance to interact. Thus, there would be no explosion, thus there would be no motion generated.
Thank you for pointing this out.
You bring up a good point, however this point contests gas laws in a vacuum, not mechanical laws. The mechanical principles which I outlined still apply, whether the gases in question would function as theoretical suggested is another matter.
Your intuition on this I believe is accurate, but it is expressed in a way which is unclear. If a controlled explosion could occur in a vacuum, then the expected motion would uphold. But, it doesn't make much sense to suggest a controlled explosion caused by a chemical reaction could be managed in a vacuum, because as you suggest there is no external pressure to ensure that two given substances mix and interact, were they somehow released from a tank into a chamber they would likely be rapidly sucked towards the low pressure opening of the chamber without ever having a chance to interact. Thus, there would be no explosion, thus there would be no motion generated.
Thank you for pointing this out.
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The_White_Lodge
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Altair,
I think like Patrix, your point is correct, but you are also confounding gas laws with mechanical laws, and so your explanation fails to be as solid as you premise.
When I speak of the recoil that occurs when firing a bullet out of a gun. This, if it were practically possible, would uphold as much in a vacuum as it would in a pool of water. If you have object A incapsulated within object B and object A is rapidly ejected from object B along a given vector in order for there to be conservation of momentum, object B must exert the equivalent force along the opposite vector. This is Newton's third law.
The scenario you speak of would involve something more akin to the bullet simply dropping out of the chamber or perhaps being sucked by an external force out of the chamber. In other words, a leak of gas rather than an explosion of gas. In which case no work would be produced and the rocket would not move. I do believe you are correct, that in a vacuum any attempt to create an explosion would be subverted by the tendency of the gas to rapidly leak out of the opening in the chamber.
It should also be noted, that the gas laws are based upon Newton's laws so one cannot favor the gas laws and reject Newton's laws of motion without ending up in a logical contradiction.
When you speak of pressure, you are speaking of gas laws, and if the gas laws applied to a vacuum or in rapidly decreasing pressure are critically considered then these will readily disprove any space rocket narratives. So, I strongly encourage you and anyone else who takes up this argument to focus your attention on gas laws and the lack of means by which the supposed mechanics of rockets can be brought into practical reality.
I think like Patrix, your point is correct, but you are also confounding gas laws with mechanical laws, and so your explanation fails to be as solid as you premise.
When I speak of the recoil that occurs when firing a bullet out of a gun. This, if it were practically possible, would uphold as much in a vacuum as it would in a pool of water. If you have object A incapsulated within object B and object A is rapidly ejected from object B along a given vector in order for there to be conservation of momentum, object B must exert the equivalent force along the opposite vector. This is Newton's third law.
The scenario you speak of would involve something more akin to the bullet simply dropping out of the chamber or perhaps being sucked by an external force out of the chamber. In other words, a leak of gas rather than an explosion of gas. In which case no work would be produced and the rocket would not move. I do believe you are correct, that in a vacuum any attempt to create an explosion would be subverted by the tendency of the gas to rapidly leak out of the opening in the chamber.
It should also be noted, that the gas laws are based upon Newton's laws so one cannot favor the gas laws and reject Newton's laws of motion without ending up in a logical contradiction.
When you speak of pressure, you are speaking of gas laws, and if the gas laws applied to a vacuum or in rapidly decreasing pressure are critically considered then these will readily disprove any space rocket narratives. So, I strongly encourage you and anyone else who takes up this argument to focus your attention on gas laws and the lack of means by which the supposed mechanics of rockets can be brought into practical reality.