1

Science & Alternative Science / Re: Do rockets push off the air?

« on: Today at 08:36:13 PM »

If we were using the word "exchange" in its everyday usage, then you might be correct.  However, we are (or at least I am) using it in the context of its scientific definition, which does not necessarily imply a 2 way trade.

Either way, you're getting hung up on semantics more than the real point: a closed system, by any scientific definition, does not gain or lose matter.  That's why it's called "closed".

Exchange means exactly that. Exchange. A closed system can lose matter.

You are lying and gaslighting. You cannot even comprehend the sources you provide to support your bankrupt position, so providing additional sources would be foolish.

So I'm just supposed to take your word for it? 

Doesn't matter to me whether you take my word for it or not.

You have been called out for it by the moderation here at this site, numerous times, being relegated to Purgatory for an extended period for exactly that.

You are claiming that a closed system can form a force pair with itself, ffs!

No, I am not claiming that.  I am claiming that objects within a closed system can, and must, force pair with each other in order to conserve momentum.  I am claiming that the rocket engine and the exhaust are two of the many objects that make up a closed system rocket and form a force pair that allows the exhaust to accelerate in one direction and the rest of the rocket to accelerate in the opposite direction.

BWHAHAHAHA! In other words, "No, I am not claiming that, but let me restate that claim here in direct response."

GTFO...

2

Science & Alternative Science / Re: Do rockets push off the air?

« on: Today at 06:00:30 PM »

Not at all. 

Two types of exchange can occur between system and surroundings: (1) energy exchange (heat, work, friction, radiation, etc.) and (2) matter exchange (movement of molecules across the boundary of the system and surroundings).

You're the one who seems to be losing sight of the word "closed" as it applies to thermodynamic systems.

Absolutely gaslighting again.

An exchange is where 1 system provides something to a 2nd system in exchange for something the 2nd system provided to system 1.

Have you read a physics text book?

Yes.

No lying or gaslighting.  Just trying to educate you.  Some words can have a somewhat different meaning in physics than in everyday usage, so I suppose that I can see how you might not be able to tell the difference.

But if you insist that I'm lying, then please provide a credible source that disagrees with me and agrees with you.  Citing yourself doesn't count.

You are lying and gaslighting. You cannot even comprehend the sources you provide to support your bankrupt position, so providing additional sources would be foolish. You are claiming that a closed system can form a force pair with itself, ffs!

Gtfo with your bs.

3

Science & Alternative Science / Re: Do rockets push off the air?

« on: Today at 10:35:58 AM »

Nobody’s lying to or gaslighting you. You’ve wasted half your breath in this thread telling people to “stop posting bs!” “leave reality to the sane!” instead of anything of real substance.

Actually, you are lying and gaslighting me again, right now with ^this post.

I have posted the exact method of how rockets and jets work within this thread and numerous times in various other threads on this forum.

All you have posted is a bunch of lying crap, merely demonstrating your ineptitude and inability to read or understand the subject matter of your op, you faker.

4

Science & Alternative Science / Re: Do rockets push off the air?

« on: Today at 06:26:59 AM »

If there is no force pair, then what causes the exhaust to accelerate in one direction and the rocket to accelerate in the other?

Have you read the thread?

And you are blind to the meaning of the word "closed". 

Propellant from outside the rocket loaded into it and then forcibly ejected back outside of it.

A closed system does not take in matter from from outside of itself or eject matter to the outside of itself.  That would be an open system.

Losing sight of the word, "exchange".

Have you read the thread?

Or are you just going to continue your lying, gaslighting ways?

If you must insist that a rocket is a closed system, then you must understand that the rocket engine and the resulting exhaust gasses are 2 elements within that closed system that can and must force pair because momentum must be conserved in a closed system. 

It isn't a case of the closed system force pairing with itself.  It's a case of the force pair happening within the closed system.  A very significant difference that you don't seem to grasp.

I see.

You are just going to continue to post bullshit and lie your ass off.

5

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 09, 2023, 10:46:09 PM »

So there is a force pair between the rocket and the exhaust gas?  Glad we have that settled.

The exhaust gas (plume) is part of the rocket. A single system cannot form a force pair with itself.

Okay, I think that I see the source of your confusion.  You don't seem to understand what "closed system" means.  A closed system does not exchange matter with its surroundings.  That's why it's called a CLOSED system. 

You already agreed that closed systems can have more than one component, therefore you must also agree that force pairs can (and indeed, must) exist within a closed system so that momentum is conserved.

I think you are blind to the meaning of the word "exchange."

A rocket does not exchange matter with its surroundings, It only gives matter (i.e., exhaust) to its surroundings. It takes in nothing from its surroundings.

A closed system cannot form a force pair with itself.

The end.

6

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 09, 2023, 10:34:26 PM »

And yes, a force pair is still required. A closed system cannot form a force pair internal to itself. In the case of both jets and rockets, that force pair can only be formed with an outside environment that has measurable air pressure. The rocket can form a working plume in an environment that has less air pressure than a jet (jets are probably capped at an altitude of of 15 miles or so), probably at around 190,000 ft. or so.

Better check again the definition of a Closed System; it is entirely isolated from its environment. 

A rifle cartridge is, and remains, a closed system; bullet goes one way, case and rifle go the other.  Force pair.  Muzzle blast irrelevant.   

A rocket motor is a closed system; combustion gases go one way, motor goes the other.  Force pair.  Plume irrelevant.

A rocket requires nothing outside of it, unlike a jet, to create thrust, ergo, a closed system.
 
I am laughing at the folly you exhibit claiming the muzzle blast has nothing to do with the recoil on a rifle...just plain bullshit. Can you help yourself at all?

A closed system cannot form a force pair with itself.

Stop posting bullshit.

7

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 09, 2023, 07:07:49 PM »

A rocket is a closed system. I haven't ignored the conservation of momentum.

You do understand that a closed system can have more than one component, don't you?

Relevance? 

The rocket engine is one component and the propellant is another.

Oh, here is the relevance. A statement of something very obvious. Thank you.

If the propellant is burnt in the combustion chamber causing the exhaust gasses to be accelerated out the back, then what balances the momentum of that accelerated exhaust gas?

Exhaust gas goes one direction, rocket goes the other direction.

Jesus, how many times must this be written?

Just what is the "relevant work " of a rocket?

It is the exhaust plume (i.e., mass ejected, at an accelerated rate) going in one direction causing the rocket or jet to go in the opposite direction.

What causes the exhaust plume to accelerate in one direction?  Or do exhaust gasses not require a force pair to accelerate?

Remember the issue you had with the words "monstrous jet of energy..." I do, but let us remind the viewing audience of the rest of asshatted posts now, shall we?

The atmoplane doesn't seem very solid to me.  Wouldn't that "monstrous jet of energy" just push the atmoplane out of its way, especially at higher altitudes where the air is much thinner?

Holy crap! It seems a rocket engine is actually capable of creating a "monstrous jet of energy". Jeez, whoda thunk?

And that "monstrous jet of energy" does indeed displace a significant amount of the atmoplane away, but still the external pressure allows the formation of a plume.   

And yes, a force pair is still required. A closed system cannot form a force pair internal to itself. In the case of both jets and rockets, that force pair can only be formed with an outside environment that has measurable air pressure. The rocket can form a working plume in an environment that has less air pressure than a jet (jets are probably capped at an altitude of of 15 miles or so), probably at around 190,000 ft. or so.

8

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 09, 2023, 01:25:08 PM »

Imagine some fuel inside a rocket. That fuel has some mass.  The fuel and the rocket have about the same relative velocity.  Now some fuel is inducted into the combustion chamber and combustion starts and the fuel’s energy is released.  The combustion chamber is closed at one end and open at the exhaust end.  Pressure inside the combustion chamber builds up due to the energy released by burning the fuel.   The combusted fuel’s mass is ejected at an accelerated rate out the exhaust end.  Newton’s law would say the accelerated fuel mass would produce an equal and opposite reaction.  That opposite force vector would be in the general direction of the nose of the rocket.


Here is your ‘force pair’.  The mass of the combusted rocket fuel being accelerated toward the exhaust port at the rear of the rocket and the forward part of the combustion chamber attached to the rocket itself.  The rocket’s mass is being accelerated in one direction and the mass of the accelerated fuel in the opposite direction.  The dividing line is the forward part of the combustion chamber as it divides the accelerating mass of the rocket itself in one direction with the accelerating mass of the combusted fuel in the opposite direction.


Any external air pressure at the exhaust end acts like a small back pressure that will slow down the acceleration rate of the exiting combusted fuel a little and reduce the forward acceleration rate of the rocket.  If the rocket is in a vacuum that back pressure will be close to zero and the burned fuel mass will be accelerated at a greater rate.  Everything takes place inside the rocket and the lack of external air has nothing to do with the fuel being accelerated in one direction and the rocket being accelerated in the opposite direction.

The mass of the exhaust is part of the closed system. No force pair can be achieved, as a single closed system cannot pair with itself.

9

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 09, 2023, 09:50:40 AM »

The exhausted gas is part of the rocket. A rocket is a closed system.

If you want to consider a rocket to be a closed system, then you must not ignore conservation of momentum.  If the exhaust is being accelerated one way, then the rest of the rocket must be accelerated the opposite way in order for momentum to be conserved.  That is, unless you think that accelerating rocket exhaust doesn't exhibit momentum.

A rocket is a closed system. I haven't ignored the conservation of momentum. You might want to read the thread before making any more lying comments.

Gas, when released to vacuum, performs 0 work.

True.

Fixed that for you.

All of the relevant work is done inside the rocket engine, before the exhaust is released into the vacuum.

Another cosigner to the foolish idea. You are probably the originator of this heaping pile of crap you are writing here in this thread. Just what is the "relevant work " of a rocket?

It is the exhaust plume (i.e., mass ejected, at an accelerated rate) going in one direction causing the rocket or jet to go in the opposite direction.

Do you wish to continue to display your lies and/or ignorance to the audience, penguin?

10

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 07:54:51 PM »

Joule's expansion.

It is about gas freely expanding when it is released to a vacuum.

Sorry, but Joule (not Joule’s) expansion is not the same thing as Joule’s Law. Gases expanding in space has nothing to do with the reaction force of the combustion moving the rocket.

Yeah, Joule has more than one.

Gas, when released to vacuum, performs 0 work.

It is a law of physics.

It is named after Joule.

Ergo, Joule's Law.

It is the product of the combustion that moves the rocket, you dyngus.

11

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 07:52:04 PM »

You are clearly stating the gas exhaust (something which is part of the rocket, a single closed system, as something entirely separate, like the other person.

It is foolish and you are writing crapola.

You are objectively wrong. Two people attached to each other is a closed system in the same way gas inside a fuel tank is.

Trying to claim a pair of people are a single unit...FUCKING HILARIOUS!!!

Tell you what, Copernicus...

Draw a goddamn diagram of a pair of people acting as a single closed system, while at the same fucking time pushing off each other so they can go opposite directions, and submit the diagram for critique to a science professor.

Once he okays that piece of crap, then post it here with the verification and I'll concede, okay?

A person pushes off of you, moving you in the opposite direction. The gas pushes off of the rocket, moving the rocket in the opposite direction. Both examples start as closed systems, and end with two parts separated by the force.

Just more crap that is so goddamn wrong it boggles the mind.

You are truly a piece of work.

12

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 07:46:49 PM »

You have absolutely no idea what you are writing. Gas released to vacuum performs 0 work. It freely expands.

Joule's Law.

That is literally not what Joule’s Law is. Joule’s Law is about the proportionality of heat generated and current through a conductor. I think we’re about wrapped up here.

Joule's expansion.

It is about gas freely expanding when it is released to a vacuum.

Forms no plume.

You are wrapped alright. Probably in a straight jacket or something.

13

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 07:40:02 PM »

Inside a combustion chamber there is the introduction of a mass of fuel at a low relative velocity.  The fuel mass is set on fire.  That releases energy.  One end of the combustion chamber is closed to the product of the combusted fuel.  The other end is open to the outside of the engine.  Since the pressure is lower on the outside, the combusted fuel accelerates out in that direction.  The accelerated fuel mass produces a force equal and opposite to its acceleration vector. 
 
Any pressure on the outside of the rocket engine will inhibit the exhausts acceleration.  Since the force is proportional to the mass acceleration the less external force outside the rocket engine the more force will be produced.  This means that a rocket will be more efficient in a vacuum than in an atmosphere.

This is correct.

This in incorrect. Gas released to a vacuum performs 0 work.

Joule's Law.

Trying to equate two people pushing off each other to the operation of a rocket is just plain stupid, so do everyone a favor and stop posting bs.

Do explain  a person pushes off of you, moving you in the opposite direction. The gas pushes off of the rocket, moving the rocket in the opposite direction. Both examples start as closed systems, and end with two parts separated by the force.

You are clearly stating the gas exhaust (something which is part of the rocket, a single closed system, as something entirely separate, like the other person.

It is foolish and you are writing crapola.

Look, I don't care how many screwed-up alts you want to recruit to chime in.

As long as your alive and post crap like tyou are posting now, you will remain wrong.

14

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 07:36:20 PM »

Inside a rocket's combustion chamber there is the introduction of a mass of fuel at a low relative velocity.  The fuel mass is set on fire.  That releases energy.  One end of the combustion chamber is closed to the product of the combusted fuel.  The other end is open to the outside of the engine.  Since the pressure is lower on the outside, the combusted fuel accelerates out in that direction.  The accelerated fuel mass produces a force equal and opposite to its acceleration vector. 
 
Any pressure on the outside of the rocket engine will inhibit the exhausts acceleration.  Since the force is proportional to the mass acceleration the less external force outside the rocket engine the more force will be produced.  This means that a rocket will be more efficient in a vacuum than in an atmosphere.

You have absolutely no idea what you are writing. Gas released to vacuum performs 0 work. It freely expands.

Joule's Law.

15

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 06:52:42 PM »

You’re holding onto someone in a vacuum.
You push off each other. According to Action80, only one of you should move (the gas should move but not the rocket).[

Two people pushing off each other is actually a force pair. You are almost getting it.

After all, before you both push you’re a “closed system”. It’s almost as if, when you push off the other person, the le momentum is… le conserved.

Trying to equate two people pushing off each other to the operation of a rocket is just plain stupid, so do everyone a favor and stop posting bs.

Rockets are, in fact, observed to gain efficiency at higher altitudes with less air resistance (varying slightly with the engine’s specified job)

No shit. You have any other obvious tidbits of drivel to add to your own op?

Rocket engines can certainly operate at higher altitudes than jets, but that is only because they carry their own oxidizers and require no air intake to accomplish combustion. Once external environment pressure drops below a certain level (i.e., pressures reported at or below the supposed "outer space"), rockets can no longer achieve propulsion due to a lack of a force pair.

16

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 05:21:27 PM »

So, all internal...

And yet all the arrows in Figure 1-1 show the exhaust traveling to to the rear.

If it truly was all internal, then the thrust would be traveling to the front, like some other jokers like to claim here.

Got the correction; thanks.  This is a simplified diagram of the gas flow through the engine; it does not illustrate thrust.

Ah, yes...the good ole "ignore what your lying fucking eyes are looking at!" argument.

It shows air being inducted from the left, compressed and impelled centrifugally by the compressor, diffused and entering the combustion chamber (to the right), passing though the turbine and exiting (to the right).  (Incidentally, the fact that the intake is to the left is just a convenience.  Many engines draw their air from all around, it doesn't matter.  The only important vector is that exhaust goes right, reactive thrust goes left).

Exhaust gas generates the thrust, period. No exhaust gas, no thrust. Exhaust gas generates a plume.

It is a simplified diagram is explaining the gas path.  To the target audience, the fact that thrust acts to the left does not require explanation.  Why would any of the arrows point left?

Because if you read the posts of the asshat train of various posters here, they are gaslighting the shit out of the issue, claiming the exhaust gas is pushing somewhere to the front of the rocket within the combustion chamber, quite similar to what you are trying to now claim happens with gas turbine engines.
 

An equivalent diagram for a road vehicle might show the engine, pistons, transmission and wheels going round.  The fact that the wheels try to push the road backwards does not need to be explained.

Nobody gives a damn about your fake analogies and comparisons.

17

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 05:13:20 PM »

You and your nephew have some pretty big balls to stand up in public and say that Newton's 3rd law of physics isn't real. I'm sure you must have some amazing proof that will blow away centuries of science. Do you have any evidence that doesn't come from your own mind or from YouTube?

You have no balls to stand up say that I have denied the third law of Newton. Equal and opposite reaction. Gas goes out one way, and the rocket or jet travels the other.

I am sure the only proof you have ever come up with in your life has some sort of warning label affixed to it warning about use during pregancy.

18

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 12:50:04 PM »

Exhaust gas accelerates right.  Reaction applies a force left.  Force pair.  Can you specify where the RR Book denies this? 

And going back a couple of posts, can you clarify you meant Fig 1.5?  That's a garden sprinkler.

Figure 1-1, corrected.

The exhaust is part of the jet or rocket. You must have one thing reacting with an entirely separate thing, not just part of itself.

19

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 09:12:45 AM »

It doesn't matter what your source claims, there is a plume related to all jets and rockets (i.e., we see what is typically called a contrail), and that plume reacts with the pressurized external environment to form a force pair, which results in movement. No force pair, no movement.

The "source" which designs, develops and manufactures jet engines, refuted by Action80's superior insight.  And possibly his nephew.

If your source claims there is no force pair, then it doesn't fucking matter what anybody says, that source is fucking wrong.

Jesus, how do you think you are going to get away with posting bullshit and somebody is not going to call you out for it?

A force pair is needed.

That is plain, pure simple physics (to quote the penguin). I cannot help you cannot read or understand what your source is claiming.

20

Science & Alternative Science / Re: Do rockets push off the air?

« on: December 08, 2023, 07:38:50 AM »

It doesn't matter what your source claims, there is a plume related to all jets and rockets (i.e., we see what is typically called a contrail), and that plume reacts with the pressurized external environment to form a force pair, which results in movement. No force pair, no movement.

A plume is a jet of plasma. A contrail is condensed water. What does a contrail have to do with anything?
Also, the “force pair” is the gas pushing against the rocket and the rocket itself. Hope this helps!

The exhausted gas is part of the rocket. A rocket is a closed system.

No force pair.