Does Rocketry Work beyond Earth's atmosphere?

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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby FervidGus on December 6th, 2017, 4:52 pm

Firstly I’d like to thank the admin who amended the embedded images in my posts so far. There’s still quite a bit of reading left on how to post neat and tidy content.

So to proceed. The points of contention with my part 1 so far have been the effect of air on a rocket, Newton’s Third Law, the rate of fuel consumption, and the feasibility of satellites existing.

Air and rockets.

When I said that,
The answer is that air in the atmosphere plays an inconsequential part in the flight of a rocket or missile.


I was keeping in context of Newton’s Third Law (NTL). And I stand by what I said. If there is a specific rebuttal you have to that point I made, and the further expounding of the point below, please post it for the benefit of all readers and posters.

When I say “inconsequential” I mean that I am ignoring factors such as air resistance the rocket encounters as it moves, and thus the whole aspect of maintaining stability in flight. Here an aerodynamic shape is key for stability, and to minimize the rocket profile, and fins (if any) are kept to a minimum. But usually the case is to have a good, stable shape.

When I say air is inconsequential for its movement it’s a sign I’m not talking about the usual flying vehicles. Simon, have you ever noticed the sudden increase in speed in planes through their history? The Wright Brothers’ first plane had a maximum airspeed of 6.8 mph, in 1903.
The P-51 Mustang had a maximum airspeed of 440 mph, in 1940.
The fastest propeller plane, XF-84H Thunderscreech, had a max airspeed of 0.83 Mach, equating to 525 mph, in 1955.

There is a leap in max airspeed as jet engines were invented.
The HE 178 had a max speed of a respectable max airspeed of 380 mph, in 1939.
The Avro Vulcan, a rather hefty bomber, had an impressive max airspeed of 0.96 Mach, i.e. 645 mph, in 1952.
And the SR-71 Blackbird had a mindblowing max speed of 3.3 Mach, i.e. 2200 mph, in 1964.
(All figures taken from Wikipedia)

Can you guess why jet engines were much faster than their propeller driven counterparts? It’s because whereas one group used air pressure differences between the front and back of its blades to slice through air to move forward, the other worked quite differently. Jet engines superheated the air using turbine fans and combustible projects to force the exhaust out from their back.

The similarity between jet engine aircraft and rockets is that they rely on speedily expelling an exhaust to push their bodies forward. This clearly demonstrates that relying on air has a limit to how fast you can fly through it using propeller blades for propulsion because the materials and engines in experimental propeller aircraft were reaching a ceiling of sorts in what more could be done to fly faster.

Obviously air and the atmosphere plays a larger role for atmosphere flying planes (i.e. those that do not ‘fly in space’) because they manoeuvre using the air and thus have relatively large wings to house ailerons for such a purpose. A missile will manoeuvre and thus will manipulate the shape of its nozzle in tandem with using fins for stability. You might imagine this as you would picture a jet fighter shooting heat seeking missiles.

Is this “my opinion”? No. My primary joy is learning and evaluating what I do know. To present my own views as fact is contrary to my principles, and doesn’t make much sense.

NTL

I’m not understanding your point here. NASA may state the same thing, however nobody has a monopoly on the truth. If you have a rebuttal to Newton’s Third Law in relation to rockets perhaps it would be a good idea to state it again for the benefit of the readers.

Rate of fuel consumption.

You quite elegantly put how a rocket will be in a spot of trouble when its fuel runs out. Unlike a plane which can glide down when its engines stop, a rocket is likely to just fall rather clumsily. Again I’m not sure what this point of yours is meant to prove. If there is sufficient fuel loaded for the journey that is to take a predicted period of time under a constantly changing mass, then there is no unfortunate dropping out of the sky or empty fuel tank misery. This is very much true for cars, electric cars, boats, planes, and plane missiles. So does the idea sound wacky to me? No, as it’s clear that running out of fuel before reaching space is a bit of a problem.

Now for a rocket or body that has been propelled into space, assuming gravity is “off” for the moment and so is air resistance, then that body will continue at the velocity is was accelerated to. After all, there is no gravitational pull to make it orbit another body, or accelerate it downwards, or air resistance to slow it down.

Feasibility of rockets and satellites.

After reviewing the arguments against the rather simplistic model of a rocket described in this topic, I’m still ambivalent as to what the main issues with it are.

NASA may explain to me how to milk a cow, but as it stands, they cannot manipulate what is known to be true, however much they may create fantastical imagery that is inconstant with itself.

In space, in accordance to Newton’s Second Law such objects travelling at a certain velocity will continue to move at equilibrium unless disrupted, for example by a collision with another object. You are quite dismissive of Newton’s Cannonball. It seems as it stands that we hold different beliefs regarding these basic laws of physics and their simple applications. Whereas you wholesale disregard them, I do not, and so am at odds to discuss something you state is false, especially because NASA has discussed it. A patient, methodical approach is required in approaching anything in science and engineering. Isolated facts on their own paint an incomplete picture of reality.

...thousands of man-made machines are currently revolving at hypersonic speeds around Earth...


As well as viewing rocketry possible in a vacuum, the existence of satellites is also something I believe to be true. Many universities with physics and engineering departments have teams building economically feasible mini-satellites, which may weigh as little as 1-10 kg. In fact I visited such a university (Surrey). The relative difficulty in launching a rocket due to legal issues relate to airspace security for a country as well as for airliners. Otherwise it’s perfectly possible for a group of people to save money to spend on a satellite which is part of a rocket payload. Within a matter of hours this small satellite will be transmitting data back to us. This is the site https://www.surrey.ac.uk/surrey-space-centre.

As for the ISS I am indifferent to it. It represents a crass expenditure of wealth and may well be a fabrication. My interests lie with what’s more practical. And robotic space research is cheaper and less "Hollywood". I highly recommend members of this forum to check out mini-satellites and how you can get involved.

without the need to push against air (which is, of course, the primary force that propels any man-made rockets / or fireworks within our atmosphere).


Here is one of the cruxes of the debate. Pushing against air may be important for a bird or a plane etc., but not for a rocket for the numerous reasons outlined above. A rocket, take for example a firework, most strikingly lacks wings. Instead its shape is reminiscent of a spear forcing air out of the way, piercing through it (notice how simple fireworks generally take a curved flight path). Inside a whole slew of gunpowder substitutes and what-not are ignited by a fuse. And the products of combustion are forced out a tiny hole, pushing upwards against the rocket. As you might have guessed, the rocket pushes downwards on the exhaust products, and visibly the firework soars upwards.

---

Patrix, thank you for your in-depth response. I feel much of my reply already has material relating to it. So to add to it, rockets do not rely on the presence of air to propel themselves. I’m afraid it cannot be distilled any simpler than this, other than to use simple models in experiments to show for it.

Ironically Kickstone’s posts clearly support what I am talking about. A pressurised hobby water rocket, let’s say 20 meters above ground with a solid stream of water being expelled, is not moving due to the water’s interaction with the air around it. Water is stable in air. Clearly it’s the opposite forces acting within the bottle causing it to fly upwards.

---

Thanks for the reply Flabbergasted.

It may appear I am speaking on my own authority, but as I said earlier, these are easily verifiable facts in the public domain. NASA is not a hydra yet capable of twisting knowledge in the public domain- slimy people and corporations mostly excel in fake media. I have read Simon’s posts and they are inconsistent with basic scientific principles, especially when the laws of Physics have been disregarded, they are not points to be easily debated with as I’ll have to enter a playing field where the ordinary laws of the universe no longer work.

As for a rocket hovering over a launchpad, if one assumes that the exhaust is not pushing against anything, then this goes against the other assumption that it pushes against air. So this point too is uncertain in how it was reached.

Can Newton’s Laws be applied to a rocket in space? Well the nature of space much be understood first, as well as the important Laws of Physics too! Primary experimentation and seeking the help of a professor unaffiliated with NASA can seriously help here. If my reasoning and stating or facts seems circular, then I’m afraid that the only recourse is a secure, formal lesson from a professor who is happy to demonstrate from first principles all the physics being discussed here.

Cluesforum is jumping into topics with insufficient knowledge to approach them with. Now this shouldn’t be a problem, as self-learning is an important skill. Yet you need at some point external tutelage to amend the errors, lest disordered analysis is applied to the tearing apart of media fakery. I’m merely a student more concerned with electricity and power rather than mechanics, yet these are topics that I too have covered in school and still study now.

The arbiters of media fakery do not play by the rules, and it is for this reason they are more likely to be found peddling fiction where disbelief is suspended i.e. in films, news, and TV etc; they may be able to use rockets to launch satellites, but the crass ISS images rely on the suspension of disbelief. It is though the TV that they relayed the totally impossible 9/11 fraud.

My reply has become rather long. I hope that it sufficiently responds to points raised by you fellow researchers, and I gladly anticipate responses to it. I have tried to remain courteous, and this is a personal principle that is inviolable; no matter how much you may disagree with somebody, to become agitated only serves to cloud ones logic and lead to bad decisions being made. Impatience breeds discord, whereas sincere interest in finding the truth builds strong bonds.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby patrix on December 6th, 2017, 5:15 pm

FervidGus » December 6th, 2017, 4:52 pm wrote:
Patrix, thank you for your in-depth response. I feel much of my reply already has material relating to it. So to add to it, rockets do not rely on the presence of air to propel themselves. I’m afraid it cannot be distilled any simpler than this, other than to use simple models in experiments to show for it.


You are welcome. I don't think on the other hand that you have anything to add here since you don't seem to understand how a rocket moves in the atmosphere (by riding on it's own shockwave) or that basic physics (free expansion) proves that rockets cannot move without interacting with surrounding molecules. You need to read up on those things.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby Flabbergasted on December 6th, 2017, 8:27 pm

FervidGus wrote:As for a rocket hovering over a launchpad, if one assumes that the exhaust is not pushing against anything, then this goes against the other assumption that it pushes against air.

It looks like you missed my point. I am saying that a rocket hovering over a launch pad is pushing against the ground. NASA (and you, perhaps) claims it pushes against the inside of its own combustion chamber solamente.

FervidGus wrote:I have read Simon’s posts and they are inconsistent with basic scientific principles, especially when the laws of Physics have been disregarded, they are not points to be easily debated with as I’ll have to enter a playing field where the ordinary laws of the universe no longer work.

Could you specify in what way Simon´s analyses contradict basic scientific principles? Actually, I wonder how anyone could be consistent with basic scientific principles in a realm "where the ordinary laws of the universe no longer work".

(I want to apologize for my short and hurried posts: I am pretty swamped at work these days)
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby simonshack on December 6th, 2017, 11:27 pm

FervidGus wrote: If there is sufficient fuel loaded for the journey that is to take a predicted period of time under a constantly changing mass, then there is no unfortunate dropping out of the sky or empty fuel tank misery.


Dear FervidGus,

Sorry, but I can't make out what exactly the above sentence of yours is supposed to mean. Please take me out of MY misery - and do your best to respond to this post of mine in cogent, intelligible manner. Thanks.

Do you realize that we are told that machines weighing up to 100.000kg (or more) are propelled up in the skies - and somehow 'placed in ANY desired orbit' - by a load of fuel sufficent only for 3 minutes of propulsion time - yet these machines keep orbiting around Earth (at "22 times the speed of sound") for DECADES on end ?

NASA is telling us that the ISS has been circling Earth for over 19 years now - at about 27,000 km/h (i.e. circa 22 X the speed of sound) :


full link: http://www.youtube.com/watch?v=1AT6Yk4DYaY

Do I really have to spell out to you (OR CAN YOU AT LEAST COMPREHEND) why I do not buy such "rocket science"?

You then wrote:
FervidGus wrote:As for the ISS I am indifferent to it. It represents a crass expenditure of wealth and may well be a fabrication.


Hmm. So, in your opinion, the ISS may well be a fabrication - yet all other purported man-made satellites (promoted by the same NASA clowns) may be true & legit?

My head hurts - only for trying to envision what sort of logic governs your mind.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby pov603 on December 7th, 2017, 8:01 am

@FervidGus
As well as viewing rocketry possible in a vacuum, the existence of satellites is also something I believe to be true. Many universities with physics and engineering departments have teams building economically feasible mini-satellites, which may weigh as little as 1-10 kg. In fact I visited such a university (Surrey). The relative difficulty in launching a rocket due to legal issues relate to airspace security for a country as well as for airliners. Otherwise it’s perfectly possible for a group of people to save money to spend on a satellite which is part of a rocket payload. Within a matter of hours this small satellite will be transmitting data back to us. This is the site https://www.surrey.ac.uk/surrey-space-centre.


I’ve highlighted the above for the following reason, it has always puzzled me that the ‘authorities’ stop us for doing such a thing presumably in fear of us hitting a ‘jet’ or landing uncerimoniously in someone’s garden yet the same ‘authorities’ tell us that they constantly launch numerous ‘things’ into the outer atmosphere where they may or may not be constantly subjected to collisions (which would seemingly cause said object to come clattering down into ones garden) with either ‘natural’ objects in space, defunct satellites, or other such satellites from other countries not being aware of the other objects’ existence (spy satellites anyone?) or just not being courteous enough (tourists driving in another country?).
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby kickstones on December 7th, 2017, 1:20 pm

patrix » December 6th, 2017, 2:50 pm wrote:Important things deserve to be repeated and I feel a responsibility since I opposed the idea of rockets not working in vacuum not long ago, before I was able to mentally grasp the basic physics involved. Let me try to explain this in some new ways, but also PLEASE go back to the beginning of this thread and start reading, researching and thinking. All you really need are in those very first posts by Boethius et. Al.



Yes, Patrix, I learnt more in those early exchanges than 3 years of physics at high school, and an exchange that sticks in my mind is the one between Boethius and Simon.....

simonshack wrote:

I believe that the impossibility of propelling a rocket out of our planet's atmosphere was discovered at an early stage of space travel experiments. Any rocket reaching a certain, critical altitude (for which I surely won't pretend to provide/ specify any exact figure) simply stalls - due to the absence of air, and plummets back into the atmosphere.

Boethius wrote

Yes, Simon. Tom Wolfe's book "The Right Stuff" documents high altitude flight tests with rocket powered aircraft that would invariably fail in the thin air and plummet back to earth. Chuck Yeager almost died in a NF-104A rocket plane failure while attempting to set a height record. These planes were liquid fuel rockets and not air-fed jets.

Why would NASA claim to be able to send rockets into space when the USAF couldn't get the same technology into even the upper atmosphere?

Why did Chuck Yeager not join the space program? Did he know it was a hoax
?

But let's suppose a rocket actually makes it one day and released water when it entered space and if the results are similar to the project High Water experiment ....

The two Project High Water launches caused the release of 95 short tons (86,000 kg) in the ionosphere.
For both of these experiments, the resulting ice clouds expanded to several miles in diameter and lightning-like radio disturbances were recorded.


https://en.wikipedia.org/wiki/Project_Highwater

....would we experience similar lightning in the so-called vacuum of space and if so could this energy source be utilised to power the craft?

Lightning

Lightning is a sudden electrostatic discharge that occurs during a thunderstorm. This discharge occurs between electrically charged regions of a cloud (called intra-cloud lightning or IC), between two clouds (CC lightning), or between a cloud and the ground (CG lightning).

Lightning electrification

The details of the charging process are still being studied by scientists, but there is general agreement on some of the basic concepts of thunderstorm electrification.

Image
When the rising ice crystals collide with graupel, the ice crystals become positively charged and the graupel becomes negatively charged.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby Penelope on March 27th, 2018, 7:55 am

FervidGus,
I just want to express agreement with your posts of December 6th, 2017. You are correct that the crux of the matter is failure to understand Newton's 3d. More specifically, without an understanding of how Newton's 3d operates within our atmosphere, it is impossible to correctly evaluate whether it's valid in vacuum.

As you know, the argument is that rockets are propelled in flight by their exhaust pushing against the air, and at lift-off by exhaust pushing against the ground. So, in flight the 3 objects are rocket, exhaust, and air; on lift-off rocket, exhaust, and ground. Newton's 3d applies to pairs.

Hence, the argument as stated cannot account for lift-off or flight in atmosphere. And so, adherence to this argument puts one in the unenviable position of having to deny Newton's 3d within our atmosphere as well.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby patrix on March 27th, 2018, 9:15 am

More specifically, without an understanding of how Newton's 3d operates within our atmosphere, it is impossible to correctly evaluate whether it's valid in vacuum.


No it is not Penelope. It is easy to perform a controlled experiment (which have been done numerous times) that disproves rockets would work in an unrestricted vacuum such as space. All needed is to show that when a gas is allowed to expand freely, it performs no work. That alone disproves that rockets can create thrust in vacuum and the physical law is called free expansion.

And no work, means no action and that in turn means no reaction and thus "no Newton" (1,2 or 3rd).

FervidGus wrote,
Can you guess why jet engines were much faster than their propeller driven counterparts? It’s because whereas one group used air pressure differences between the front and back of its blades to slice through air to move forward, the other worked quite differently. Jet engines superheated the air using turbine fans and combustible projects to force the exhaust out from their back.

The similarity between jet engine aircraft and rockets is that they rely on speedily expelling an exhaust to push their bodies forward. This clearly demonstrates that relying on air has a limit to how fast you can fly through it using propeller blades for propulsion because the materials and engines in experimental propeller aircraft were reaching a ceiling of sorts in what more could be done to fly faster.


This is incorrect. The similarity between rockets and jets are that they heat up the air behind them, making it expand and becoming more dense which increases the momentum of the gas pushing against it. And when the air cools down again it contracts, resulting in the surrounding air rushing in to equalize the pressure which creates a shock wave that further pushes the rocket/jet forward.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby Penelope on March 28th, 2018, 12:21 am

Patrix,

The challenge for any argument which would defeat the accepted theory of rocketry is that it must explain the success of rocketry within atmosphere in such a way that the same technology fails in vacuum: "Here is Newton's 3d working on lift-off & in atmosphere, and it will not work in space because . . . ."

I have thrown out a direct challenge that Newton's 3d, as interpreted by the "Rocketry won't work in space" argument, cannot lift the rocket from the pad:
the argument is that rockets are propelled in flight by their exhaust pushing against the air, and at lift-off by exhaust pushing against the ground. So, in flight the 3 objects are rocket, exhaust, and air; on lift-off rocket, exhaust, and ground. Newton's 3d applies to pairs.
Hence, the argument as stated cannot account for lift-off or flight in atmosphere.

by patrix » March 27th, 2018, 12:15 am

More specifically, without an understanding of how Newton's 3d operates within our atmosphere, it is impossible to correctly evaluate whether it's valid in vacuum.

No it is not Penelope. It is easy to perform a controlled experiment (which have been done numerous times) that disproves rockets would work in an unrestricted vacuum such as space. All needed is to show that when a gas is allowed to expand freely, it performs no work. That alone disproves that rockets can create thrust in vacuum and the physical law is called free expansion.

And no work, means no action and that in turn means no reaction and thus "no Newton" (1,2 or 3rd).

Patrix, you may not ignore any potential error in your conception of Newton's 3d, carry the error into space, and use it to invalidate the real Newton's 3d. If you are to invalidate the real Newton's 3d in space, you must begin with it at lift-off, carry it through the atmosphere, and only then invalidate it in space.

Regarding the free expansion of gas experiment. There is frequently incompleteness in the findings of the experiment itself, there is an error in its presentation, there is another in its application to the rocketry problem, and I expect to find it irrelevant to the entire question.

But to speak about the effect of vacuum upon a rocket propelled by any valid/invalid version of Newton's 3d seems premature while yours is still on the pad. Please demonstrate that your version of Newton's 3d is able to get that rocket off the pad.

This is what a demonstration of Newton's 3d looks like:

I sit in my wheeled desk chair in a smooth concrete court. My feet are on the struts that connect the wheels to the chair, not on the ground. There is a heavy plastic bag of sand in my lap. I throw it forcefully and the expected backward motion of me + chair occurs. The bag's motion and chair's opposite-direction motion occur simultaneously. Or rather, the force on each is determined at the instant before separation.

My palms push on the sand bag, the weight of which resists me. There is a force vector down my arm, through my palm, and with an arrowhead contacting the sand bag. Likewise, the weight of the sandbag by resisting sends a force vector up my arm and pointing to my shoulder. I prefer to draw the force vectors as a single two-headed vector because it reminds me that this is a single event in time and magnitude, differing only in direction.

Your job is to demonstrate that the three objects-- rocket, exhaust and ground-- each having a force vector can somehow arrange their 3 vectors into pairs, and therefore achieve lift-off.

I despair of saying it more clearly. Here, try this:

Lift-off, here in atmosphere, requires Newton's 3d.
Newton's 3d consists of paired entities exerting paired forces in opposite directions.

Your argument concerning lift-off and flight in atmosphere insists on 3 entities exerting 3 forces.
When you take this version of "Newton's 3d" to space it doesn't work. Not surprising-- it doesn't work here either.

If anyone on the site would like an approximately 8 paragraph tutorial on Newton's 3d, so that you don't continue just making it up, I would be happy to supply it.

In the meantime, I won't dilute the question of whether Newton's 3d is being properly applied here in atmosphere by discussions of the misunderstood Free Expansion experiment or debates about how airplanes work.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby patrix on March 28th, 2018, 7:09 am

Oh please Penelope I am not "ignoring/invalidating" Newtons 3rd. Or "his" 1 or 2 either.

I'm explaining that they never come to play when gas expands in vacuum since no action/reaction occurs.

This used to be school physics.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby Penelope on March 28th, 2018, 8:45 pm

Postby patrix on March 28th, 2018, 7:09 am
Oh please Penelope I am not "ignoring/invalidating" Newtons 3rd. Or "his" 1 or 2 either.

Patrix, it's my understanding that the very heart of your argument is that "Newton's 3d is not valid in space (vacuum). I agree with you that your version of Newton's 3d isn't valid in space.

I'm making the point that your version of Newton's 3d doesn't work here on Earth either, because it is a mistaken interpretation of Newton's 3d.

Patrix said, I'm explaining that they never come to play when gas expands in vacuum since no action/reaction occurs.

I can't think that discussing the effects of a mistaken interpretation of the Free Expansion experiment upon a mistaken interpretation of Newton's 3d will possibly illuminate the matter. I challenge you to defend your version of Newton's 3d here on earth where we are aided by observation and have the hope of some intuitive knowledge or perception.

Let me show you why I think your version of Newton's 3d is false.

As you know, Newton's 3d states that when material objects interact the force that object A exerts upon Object B must be synchronous and equal in magnitude to an obligatory force which Object B exerts on Object A, but in a direction 180 degrees opposite. "Obligatory" because there are no unmatched forces, there are only paired forces.

STANDARD NEWTON'S 3D AT LIFT-OFF

At lift-off the force vector which indicates the rise of the rocket is a line from bottom to top of the rocket with an arrowhead at the top. This vector MUST be matched by one in the opposite direction, so we draw another in the opposite direction indicating en masse the many exiting molecules and particles of the exhaust. The exhaust arrowhead points downward 180 degrees opposite to the rise of the rocket. Newton's 3d is satisfied and, provided the mass x velocity of the exhaust is sufficient, the rocket rises.

YOUR VERSION OF NEWTON'S 3D AT LIFT-OFF

Let's start at the element that you have added to Newton's 3d, the "push off" of the exhaust gases upon the ground as a means of raising the rocket: The exhaust vector points downward and is met by one pointing upward from the ground, indicating that the ground is exerting a resistant force equal in magnitude to that of the exhaust vector. Now what? We have stasis, cancellation of forces. How do we get from this a vector to push on the rocket? (Not even a supplementary force.) You have paired the forces of your entities in such a way that your rocket will never rise.

I say "you", Patrix, but I mean anyone's adherence to the idea that a rocket can lift off only if its exhaust pushes on the ground; or propel itself only by pushing on air. It's just that you've been the only one brave enough to speak up. And I do appreciate your response.

I don't mean to be unresponsive to your point about Free Expansion, so I will say this much: The reason for Boetius' inserting it into the discussion was to give scientific buttress to the idea that rockets cannot propel themselves by trying to gain traction through spewing exhaust against vacuum.

But Patrix, this is not an idea at issue. I agree. I'll wager so would FervidGus. No one doubts that pushing on vacuum will get you nowhere; in fact it is impossible to push on vacuum, for it doesn't resist and you therefore have a violation of Newton's 3d regarding paired forces. You try, right now, to push on air & you'll see what I mean.

Rockets don't use this method of propulsion; they have Newton's 3d. The real one, sans pushing their exhaust against ground, air or vacuum.
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby simonshack on March 28th, 2018, 9:39 pm

Dear Penelope,

Please read & view this old post of mine (from 2013): viewtopic.php?p=2385791#p2385791

Then, come back to us and explain :

1: Why do NASA / ESA / SpaceX rockets always lift off sooo very slowly?
2: Why do real amateur rockets (such as Steve Eves' 1/10 scale replica of the [alleged] Saturn V ) lift off ... like a shotgun's bullet?

See, it doesn't really matter what Isaac Newton has to say about this. We can, more simply, use our own brains to detect the fakery being sold to us.
If you really believe that those two silly TV ladies are standing in front of real rocket launches, I'm afraid that you are beyond help (sorry, no offense meant).

Needless to say, Steve Eves' 1/10-scale replica rocket didn't make it out from our atmosphere: it only reached one kilometer or so of altitude - and then fell back to Earth (he states that his rocket was completely full of fuel - and had no 'payload', such as astronauts, etc...). So what sort of magical technology (or special fuel) do you think NASA has to make a 10X larger rocket with three adult men aboard reach 100 km of altitude - and beyond (all the way to the Mooon - and back)?

As for your (old & tired) example of a person throwing an object from a wheeled desk chair on a smooth concrete surface, it just doesn't seem to be comparable to the forces necessary to lift a person vertically up from the ground - so as to escape 'gravity' - and fly up in the sky at great speeds :
Image
Yet, NASA tells us that - as rockets exit our atmosphere, they keep rising thanks to the rocket's fuel being flung out of the same!
"Newton's 3d law!", they say... I say: duh!

Please get real, dear Penelope - you are obviously a very smart (yet ever-so-slightly brainwashed) individual!

(Dearest Penelope, please excuse me - but I think we are all very, very weary of having Newton's 3d law being used to support the idea of space travel. Thanks for your kind comprehension)
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby patrix on March 28th, 2018, 10:02 pm

Rockets don't use this method of propulsion; they have Newton's 3d. The real one, sans pushing their exhaust against ground, air or vacuum.

Oh, Newtons 3d the real one! Forgot about that one :blink:

For the third time, I have no problem with Newton's laws of motion, except maybe that I doubt if he actually is the one who formulated them. But the laws are perfectly fine and valid.

Thing is, they never come into play in the rockets in vacuum scenario and I have explained why, and it's been proven with controlled experiments.

But let's give another example just for fun

Imagine you have a popcorn machine on wheels in an empty room. Now would the machine move if the finished popcorns came out at the back? Well probably eventually when a sufficient pile of popcorns had built up so that the newly popped popcorns could act against them.

Same thing with a rocket in vacuum. If the molecules resulting from a gas expansion have nothing outside the system to interact with then no reaction and hence no Newton.

And there can be no "piling" in an unrestricted vaccum. The molecules following the first cannot act on them since they all drift away at constant speed in the frictionless vacuum.
patrix
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby Penelope on March 29th, 2018, 5:30 am

Simon and Patrix,

Notwithstanding distractions like Free Expansion of gases, how airplanes work, the extent of the space program hoax, whether numerous "lift-offs" are fakery, and evidence pertaining to all-- notwithstanding all this I cleave to the single point which I made in my opening comment and expressed at length in my March 28 7:09 post.

My demonstration that a rocket on lift-off could not benefit from any force consequent to the exhaust hitting the pad or ground demolishes CluesForum's argument that this force is necessary for lift-off. Likewise, that rockets derive force from the exhaust hitting air.

It does not mean that all rocketry problems are solved, Van Allen belt, etc, or that the oligarchs choose to spend resources on space rather than on our subjugation.

I know that neither of you are interested in this analysis new to CF, and I will therefore spare you the longer explanation of how Newton's 3d works, in favor of explaining how one aspect works:

As I sat in my wheeled chair on the smooth surface and threw the sandbag which resulted in my chair moving backwards I noticed that the determining instant was the last one prior to the sandbag separating from my palms. When we had separated by a hairsbreadth, both our propulsions had already been determined and neither could be affected by what became of the other. (ahem, ahem) Capisce?

I challenge anyone on this site to disprove my interpretation of Newton's 3d in the March 28 7:09 post or on this one. I welcome all questions or comments concerning the point that I am making: That rocket lift-off & propulsion are not accomplished via exhaust pushing against ground or air.
Penelope
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Re: Does Rocketry Work beyond Earth's atmosphere?

Postby Penelope on March 29th, 2018, 6:07 am

by patrix » March 28th, 2018, 1:02 pm
I have no problem with Newton's laws of motion. . . perfectly fine and valid. they never come into play in the rockets in vacuum scenario

Patrix, your belief that Newton's 3d doesn't come into play in vacuum is because you interpret Newton's 3d to mean that rockets travel by pushing against either air or ground. This is expressly denied by Newton's 3d because it deals only with relationships between pairs. Air or ground makes 3.

You may avow Newton's 3d or that third entities like air or ground determine the outcome of paired forces transacted by paired material objects-- namely the rocket and its exhaust one instant before it separates from the rocket. You can't have both; you have to choose. Please review my discussion last post concerning force vectors. Just as numbers are necessary for math, force vectors are necessary to analyze forces.

Further, regardless of the misinterpretation & misapplication of the Free Expansion experiment, I'm sure that you are aware that vacuum is not a force, and therefore cannot stop or slow speeding bits of exhaust. However this is actually irrelevant because the transactional force between the exhaust & rocket will have already taken place, an instant prior to separation. This means that the force (resulting in motion) will already have been apportioned between them, so that nothing which happens to one can now affect the other.
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