Does Rocketry Work beyond Earth's atmosphere?

[Altair]

Anyway, I think it could be much, much simpler than that. Forget about Joule-Thomson, Newton's third law & so on. It's more than enough with the 2nd law.
If we want to accelerate a solid body, we must apply a force upon it. Period.
In a rocket, the only places where we can do that are the nozzles, and to a lesser extent, the combustion chamber. And the only way a gas can exert a force upon a solid body is by means of its PRESSURE. We can give a hoot about temperature and energy of exhaust gases, because all that matters is the gas pressure in the nozzle and combustion chamber. More precisely, its longitudinal component, because the horizontal forces get neutralized between themselves. So the question boils down to: "Is it possible to maintain a sufficient gas pressure for propulsion in the nozzle under vacuum conditions?"

I'll elaborate on this later, as now I'm writing in my tablet and this is slow as molasses, but I hope I've expressed at least the stub of the idea.

[kickstones]

Would using seawater in a rocket in space have any benifits?

I'm getting a bit puzzled by these posts about water rockets, and this one does it since it implies rockets goes to space, which this thread in its very first post demonstrates they cannot. I suggest another thread for this matter.

And a “water rocket” is a pretty bad idea since water is not very compressible and cannot effectively turn into high volume gas through expansion or chemical reaction. The toy water rockets work by recoil. Compressed air forces the water out and the rockets go up ten, twenty meters or so.

Patrix, the title of the thread is 'Does Rocketry Work beyond Earth's atmosphere?' it does not specify what type of propellent a rocket has to use to get it to work in space. I asked the question would a water emitting rocket work in space? based on laboratory experimental data namely that water freezes in a vacuum.

http://www.youtube.com/watch?v=UG7nsZkVZc0

full link: http://www.youtube.com/watch?v=UG7nsZkVZc0

And if replicated by a rocket emitting water in the so-called vacuum in space would this result in the same resulting water to ice transformation thus giving mass for following saltwater emitted to react against, along with solar radiation / wind and dust particles from past comet distribution.

We know comets exist because people have witnessed them long before NASA came along and NASA informs us that the ice surrounding the comet re-acts much the same way as that of rocket boosters.

Therefore suggesting if ice is formed by the water emitting rocket and a similar took place it would help maintain momentum of the rocket in the vacuum of space whereby it is stated 'In rockets, due to atmospheric effects, the specific impulse varies with altitude, reaching a maximum in a vacuum.'

Now I am sure that a mere layman on Cluesforum such as me is not the only person to consider these thoughts, especially if as been suggested in this thread that gases emitted by conventional rockets will not work in the void of space and even if they did it still might be worth looking at other models such as the idea of water based rockets beyond the earths atmosphere for they could be more efficient than present models, seawater would be monetary efficient at the very least.

From Quora.....

https://www.quora.com/How-much-does-NAS ... ocket-fuel

Stats for the space shuttle according to a 2001 NASA fact sheet:

NASA bought hydrogen at 98 cents per gallon. A gallon of liquid hydrogen weighs 0.2679 kg, so they paid $3.66 per kg for liquid hydrogen.

NASA bought oxygen at 67 cents per gallon. A gallon of liquid oxygen weighs 4.322 kg, so they paid $0.16 per kg for liquid oxygen.

Total amounts for those interested:

384,071 gallons of liquid hydrogen in the external tank of the shuttle, for a cost of $376,389.58. ~141,750 gallons of liquid oxygen for a cost of $94,972.50. The total cost of all propellant for "rocket fuel" is $1,380,000. These numbers exclude the hydrogen and oxygen used for cooling, etc.

Sources:
http://www.uigi.com/o2_conv.html
http://www.uigi.com/h2_conv.html
http://www.google.com/url?sa=t&r...

This begs the question why did not NASA carry out their Project High Water at higher altitudes than the two at 105 km (SA-2) and 165 km (8A-3)?

An Analysis of the Second Project High Water Data
https://ntrs.nasa.gov/archive/nasa/casi ... 078055.pdf



Why not carry out the release of water at outer limits of the thermosphere or wherever the void of space is, surely more valuable information would have been obtained than to the official explanation 'what would happen to an aborted rocket payload.'

And if this was the real reason for the experimental data why was regular rocket fuel not used?

Could it be as Boethius pointed out on the first page.....

"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?"

Did NASA carry out the High Water experiments because it wanted to see if the rocket water to ice momentum scenario would work however the environmental conditions were not favourable and it failed and the official explanations for them taking place were a guise because they were hardly likely to tell the public the real reason behind the experiments.

Which, if so, leads me to postulate that, yes, rockery can work beyond the earths atmosphere it's just we cannot, as yet, get there.

Anyway Patrix I must correct you on the statement..

Compressed air forces the water out and the rockets go up ten, twenty meters or so.

Class A Single Stage Altitude Record

Ascension III Launching to a new world record altitude.
Ascension III Water Rocket launching to a new world record altitude.
Stuart Swan - UCT
Ascension III
2723 Feet. (830m)
August 26, 2015


Class C Flight Duration Record

The rocket that holds the flight duration world record.
[D&P]Rockets*
Project 1.5
1.47 min

http://wra2.org/WRA2_Standings.php

I wonder what the duration would be in the void of space and less gravitational pull?

[simonshack]

Dear FervidGus, you wrote:

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

Next time you submit such radical opinions of yours, please type "In my opinion..." in front of your sentence. You see, kids may be reading this forum - and we do not wish to contribute to the Nutwork's ongoing 'dumbing-down' programme. Btw, what is inconsequential to me is the above opinion of yours - since it is, quite frankly, absurd.

The primary means of propulsion for a rocket (in context of part 1) is through application of Newton's Third Law; the faster the rate of 'chucking' exhaust propellant, the greater the velocity of the rocket as the 'pushing' forces are greater.

Yes, we have heard that one before - a million times, in fact - thank you very much. You know, this is precisely what NASA (et al) keep telling us. They also say that their rockets all expend their fuel within 3 minutes (or less) of being launched. Now, in your (best) opinion, what exactly will the rocket be 'chucking out' - once it runs out of fuel? A payload of medicine balls, perhaps? It is my (best) opinion that a rocket will plummet back to Earth - as soon as its fuel is exhausted. Does this opinion of mine sound wacky to you?

< (NASA's favorite 'explanation' for how rocketry works)

See, what we are actually discussing here is the feasibility of launching a rocket beyond 100 km of altitude (the so-called "Karman line") and keep it hurtling across space at hypersonic speeds for days, months, years - or even decades (as we are told most satellites and Space Stations do). Thus, unless you have - for some reason - elevated in your mind Newtons's cannonball thought experiment to some sort of real-world physical possibility, your hitherto-submitted opinions on this matter are, you may admit, no more than thin air. The problem is: a thought experiment is no more than a thought experiment. What we are being told (as fact) is that thousands of man-made machines are currently revolving at hypersonic speeds around Earth - solely by virtue of their initial 3-minute "push" into space. I think that our readers are more interested in your opinion about this outlandish "fact" (peddled by NASA et al) - rather than any disquisitions about how 'chucking out matter out of a rocket' could theoretically propel the same, by virtue of recoil forces only, 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).

[patrix]

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.

Think of the atmosphere as a sea. In a sea, we have a sea bottom where the pressure is high because all the water above and we have the shallows where the pressure is low. Then there is the water surface where the water ends and another element begins that we call air. This element actually contains a lot of water also but in gas form and there is less water the higher we get.

So if we view the atmosphere as a “sea of air”, then we call the waterline of that sea the Karman line. That is where the shallows of our air sea ends and where another element begins. It was previously called the Ether but then Einstein and other gods of science saw it fit that this element should not have a word, so today we refer to it as the vacuum of space, which can be argued wrong since vacuum strictly means something entirely void of matter, but for practical reasons I use that word.

With this in mind we go to the laws of physics. Newtons laws of motion and fluid dynamics in particular. Fluid dynamics is about how fluids and things in fluids behave and gas is also a fluid here.

A boat and a fish moves by moving the surrounding water. And if we lift them out of the water they will not move anymore because their way of creating motion through their interaction with the surrounding molecules is not something that works when they are in gas form.

A bird, a plane and a rocket, moves by moving the surrounding air. And if we lift them out of the surrounding air they will not move anymore because their way of creating motion through their interaction with the surrounding molecules is not something that works if those molecules are not present.

Newton need not apply here since the first law stipulates that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.

In the case of rocketry it might be a bit harder to understand how that external force is created since they don’t have a propeller or flap their wings but you can think of it this way – When we throw a rock into water we get an “up burst” in lack of a better word. This is because the rock moves the water to the sides and then the water rushes back creating a pressure wave. This is also how rockets gets their thrust in the air. The hot gasses from the rocket pushes away the air and when it rushes back it propels the rocket forward.

It might be the case that rockets are more efficient in thin air compared to jet engines because of their different way of creating thrust, but its clear that they have no way of working without air entirely.

[Flabbergasted]

...given enough fuel to facilitate thrust, a missile/rocket is able to reach space...
...air in the atmosphere plays an inconsequential part in the flight of a rocket or missile...
...a chemical reaction such as combustion is unaffected by low gravity or a vacuum...

Simply saying something does not make it so. Have you at all read Simon´s analysis of NASA´s claim that rockets do not push against anything, even when they are hovering over the launch pad?

...combustion is the primary source of energy for propelling the rocket due to Newton's Third Law...

Of course combustion is the primary source of energy for propelling a rocket, but that doesn´t tell us how or whether Newton´s laws can be applied to rocket propulsion in space.

Your reasoning is circular and the conclusions are not supported by the premises.

[FervidGus]

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.

[patrix]

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.

[Flabbergasted]

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.

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)

[simonshack]

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:

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.

[pov603]

@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?).

[kickstones]

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.


When the rising ice crystals collide with graupel, the ice crystals become positively charged and the graupel becomes negatively charged.

[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]

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]

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]

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.