Does Rocketry Work beyond Earth's atmosphere?

If NASA faked the moon landings, does the agency have any credibility at all? Was the Space Shuttle program also a hoax? Is the International Space Station another one? Do not dismiss these hypotheses offhand. Check out our wider NASA research and make up your own mind about it all.
kickstones
Member
Posts: 368
Joined: Wed Jan 16, 2013 1:15 pm

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by kickstones »

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.
Penelope
Member
Posts: 68
Joined: Fri Jan 19, 2018 3:48 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by Penelope »

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.
patrix
Member
Posts: 712
Joined: Wed Dec 14, 2016 10:24 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by patrix »

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.
Penelope
Member
Posts: 68
Joined: Fri Jan 19, 2018 3:48 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by Penelope »

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.
patrix
Member
Posts: 712
Joined: Wed Dec 14, 2016 10:24 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by patrix »

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.
Penelope
Member
Posts: 68
Joined: Fri Jan 19, 2018 3:48 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by Penelope »

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.
simonshack
Administrator
Posts: 7341
Joined: Sun Oct 18, 2009 8:09 pm
Location: italy
Contact:

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by simonshack »

Dear Penelope,

Please read & view this old post of mine (from 2013): http://cluesforum.info/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)
patrix
Member
Posts: 712
Joined: Wed Dec 14, 2016 10:24 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by patrix »

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.
Penelope
Member
Posts: 68
Joined: Fri Jan 19, 2018 3:48 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by Penelope »

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
Member
Posts: 68
Joined: Fri Jan 19, 2018 3:48 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by Penelope »

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.
patrix
Member
Posts: 712
Joined: Wed Dec 14, 2016 10:24 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by patrix »

Patrix, your belief that Newton's 3d doesn't come into play in vacuum
That no work occurs during free expansion is not a "belief". It is a proven physical fact.
pov603
Member
Posts: 870
Joined: Thu Jun 30, 2011 8:02 pm

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by pov603 »

Without wishing to trivialise matters can someone consider the following?
A "closed tube" is managed to be placed into "space" in an area relatively free of gravity but, nevertheless, supposedly in a vacuum.
We then insert a human within the "tube" and ask that he spend time walking to one end of the "tube" and running as fast and hard as he could towards the other end of the "tube" smashing into the wall/closed end, then calmly walking back to the other end to repeat the exercise over and over again.
Would we achieve forward momentum in this friction-less abyss?
Would a "transactional" force between the "tube" & man have already taken place, an instant prior to the impact?
Would it be safe to assume that the "tube" would not only move forward but also go faster and faster, after each repeat of the above, as there would be an absence of friction/air-resistance to slow it down?
patrix
Member
Posts: 712
Joined: Wed Dec 14, 2016 10:24 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by patrix »

pov603 » March 29th, 2018, 8:57 am wrote:Without wishing to trivialise matters can someone consider the following?
A "closed tube" is managed to be placed into "space" in an area relatively free of gravity but, nevertheless, supposedly in a vacuum.
We then insert a human within the "tube" and ask that he spend time walking to one end of the "tube" and running as fast and hard as he could towards the other end of the "tube" smashing into the wall/closed end, then calmly walking back to the other end to repeat the exercise over and over again.
Would we achieve forward momentum in this friction-less abyss?
Would a "transactional" force between the "tube" & man have already taken place, an instant prior to the impact?
Would it be safe to assume that the "tube" would not only move forward but also go faster and faster, after each repeat of the above, as there would be an absence of friction/air-resistance to slow it down?
Of course it would not move. I mean it could bounce back an forth but this would never cause it to travel in any different direction than it did in the first place. If it did it would be a violation of Newtons laws of inertia, that rocket believers hold so dearly to their chest.

If the body is not affected by an outside force it will keep its current direction and momentum. The human inside is not an outside force.

Take it from the horses mouth: https://www.grc.nasa.gov/www/k-12/WindT ... otion.html
pov603
Member
Posts: 870
Joined: Thu Jun 30, 2011 8:02 pm

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by pov603 »

Believe me, I would not have expected it to move either (almost like trying to pull oneself up by ones own laces...it ain’t gonna happen...), nevertheless we are told that satellites use Reaction Wheels to rotate etc.
Anyway, back to the tube, consider that when running at the wall of the tube it miraculously opened for a nano-second and allows the human to pass through.
What happens to him and what happens to the “tube”?
They both move in opposite directions?
He moves in one direction and the tube remains stationary?
Neither of them move?
patrix
Member
Posts: 712
Joined: Wed Dec 14, 2016 10:24 am

Re: Does Rocketry Work beyond Earth's atmosphere?

Unread post by patrix »

pov603 » March 29th, 2018, 1:07 pm wrote:Believe me, I would not have expected it to move either (almost like trying to pull oneself up by ones own laces...it ain’t gonna happen...), nevertheless we are told that satellites use Reaction Wheels to rotate etc.
Anyway, back to the tube, consider that when running at the wall of the tube it miraculously opened for a nano-second and allows the human to pass through.
What happens to him and what happens to the “tube”?
They both move in opposite directions?
He moves in one direction and the tube remains stationary?
Neither of them move?
An action/reaction can only occur when a force outside the system/body acts on it. This is why the gun/bullet scenario would work in the assumed frictionless and gravity free space. The bullet becomes something outside the system that the gas expansion from the gunpowder can react against. So if the tube is open in one end and that human jumps, pushing the tube one way and itself the other way, the tube would change direction. But that can never occur as long as that human remains inside the system.
Post Reply