[Action80]

A closed system can lose matter.

No, it cannot.  That's why it's called a closed system.  You're thinking of an open system.  If you don't believe me, then let's ask Professor Google:
 https://letmegooglethat.com/?q=can+a+closed+system+lose+matter

Of course you won't believe the internet either because it uses the word "exchange" in reference to matter entering or leaving a system.  Maybe this video will help:

Jesus, you just will not quit posting continued bullshit in response. Amazing! You have not changed one bit.

A rocket is a closed system.

Once it is on the launchpad and ready to fire, it takes in nothing else from any system external to itself. It does, however, lose matter (i.e., its exhaust gas) to its external environment.

No exchange takes place.

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

*sigh*  Okay, so you don't understand the difference between "with" and "within" either.  Here's a hint: "within" means "inside".  So when I say that objects can force pair within a closed system, I mean that objects can force pair inside a closed system.  Does that help?

No....https://physics.stackexchange.com/questions/419854/why-an-internal-force-cannot-move-a-closed-system-externally

[DuncanDoenitz]

So, the rifle bullet thing; 

https://www.uu.edu/dept/physics/scienceguys/2002Sept.cfm

Union University uses a machine gun as an example of a closed system. 

[RonJ]

I consulted my physics book that I used while pursuing my engineering degree years ago.  It seems that many people back in the 1920s also insisted that a rocket wouldn’t work in a vacuum.  It took a person like Robert Goddard to prove that supposition wrong.  There were many in the popular press of the day that had lots of fun and called him “Moon man”.  He finally put a gun inside an evacuated jar that fired a blank and proved without a doubt that a rocket would work in space.  He also earned lots and lots of US Patents for his ideas.  Eventually the press printed some retractions and apologies when the advancing space program proved repeatedly that rockets can and do work in a vacuum. 
 
The bottom line is that either there are countless physics PhDs who are correct about their knowledge of the conservation of momentum, or rockets do not work in space as claimed and the whole think is a big farce perpetrated on the public worldwide. 

[Realestfake]

In this thread Action80 denied that two people attached to each other is a closed system. He is objectively wrong about what a closed system is in kinematics - this isn’t my opinion. That is a textbook example of simple action/reaction - two people pushing off each other.

Abstractly, it is the same concept as gas pushing against a rocket. Before the action, the two actors (fuel and rocket, person 1 and person 2) are connected. After the action, there is a force that pushes both of them apart from each other. There’s no wriggling out of this being the case.
Sorry Action, but your whole plume obsession is completely unfounded and not based on really anything at all.

There is mountains of research and engineering that goes into the smallest aspect of parts such as RCS thrusters that take payloads to Mars. They are designed in a very particular way to work long-term in the harsh environment of space.

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

Nice argument. How scientific.

Person is pushed against by person. Rocket is pushed against by exploding fuel. That’s it. Not really worth a 6 page thread.

[RonJ]

I ‘cheated’ again and fetched my thermodynamics book I used in college and looked at the 2^nd chapter where the author did discuss the differences between open and closed systems.  One important matter is the determination of the system boundaries.  If you define your system boundaries as X and there is any mass crossing that boundary then it’s considered to be an OPEN system.  This means that Action’s defined system could be a closed system only if the defined boundaries were the entire universe.  No telling where the substances of the rocket’s plume will end up billions of years from now.  Even if you did assume that the entire universe was the system’s boundaries, you still have the problem of the conservation of momentum.  Fuel inside a rocket is observed to exit at an accelerated rate so to produce that acceleration requires a force.  The burned rocket fuel is observed to be exiting out the back of the rocket so the force cannot be from the outside.  Remember, force and acceleration are both vector quantities.  The accelerated fuel must have had something inside the rocket to push against, and that would be the combustion chamber.  It wouldn’t be surprising to see the rocket move in the direction opposite of the plume assuming that the rocket is free to move and isn’t tied down to something. 

[markjo]

A rocket is a closed system.

Once it is on the launchpad and ready to fire, it takes in nothing else from any system external to itself. It does, however, lose matter (i.e., its exhaust gas) to its external environment.

If there is truly nothing that anyone can say or do to prove to you that a closed system cannot lose matter to its external environment, then there is no point in further discussion. 

[Action80]

I consulted my physics book that I used while pursuing my engineering degree years ago.  It seems that many people back in the 1920s also insisted that a rocket wouldn’t work in a vacuum.  It took a person like Robert Goddard to prove that supposition wrong.  There were many in the popular press of the day that had lots of fun and called him “Moon man”.  He finally put a gun inside an evacuated jar that fired a blank and proved without a doubt that a rocket would work in space.  He also earned lots and lots of US Patents for his ideas.  Eventually the press printed some retractions and apologies when the advancing space program proved repeatedly that rockets can and do work in a vacuum. 
 
The bottom line is that either there are countless physics PhDs who are correct about their knowledge of the conservation of momentum, or rockets do not work in space as claimed and the whole think is a big farce perpetrated on the public worldwide.

Tell you what, find a video where a CO2 canister is opened to a vacuum on the level of that given for outer space (i.e., 1.322 × 10^-11 Pa.) If that canister moves, I'll retract.

[Action80]

In this thread Action80 denied that two people attached to each other is a closed system.

ITT, faker demonstrates he has no clue what a closed system is.

He is objectively wrong about what a closed system is in kinematics - this isn’t my opinion. That is a textbook example of simple action/reaction - two people pushing off each other.

ITT, faker provides no textbook.

Abstractly, it is the same concept as gas pushing against a rocket. Before the action, the two actors (fuel and rocket, person 1 and person 2) are connected. After the action, there is a force that pushes both of them apart from each other. There’s no wriggling out of this being the case.
Sorry Action, but your whole plume obsession is completely unfounded and not based on really anything at all.

Sorry faker, but the plume of the rocket, which is a closed system.

There is mountains of research and engineering that goes into the smallest aspect of parts such as RCS thrusters that take payloads to Mars. They are designed in a very particular way to work long-term in the harsh environment of space.

Hey, believe your cool story bro. Outer space travel is fiction.

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

Nice argument. How scientific.

Person is pushed against by person. Rocket is pushed against by exploding fuel. That’s it. Not really worth a 6 page thread.

You wrote a bunch of crap. Two people pushing off of each other is not an example of a closed system, period.

One single person is not a closed system, let alone two people.

[Action80]

A rocket is a closed system.

Once it is on the launchpad and ready to fire, it takes in nothing else from any system external to itself. It does, however, lose matter (i.e., its exhaust gas) to its external environment.

If there is truly nothing that anyone can say or do to prove to you that a closed system cannot lose matter to its external environment, then there is no point in further discussion.

If there is truly nothing that anyone can say or do to prove to you that a rocket (i.e., a closed system) can lose matter to its external environment (i.e., exhaust gas) then you need to stfu and never post any more the bs you love so well.

[Action80]

So, the rifle bullet thing; 

https://www.uu.edu/dept/physics/scienceguys/2002Sept.cfm

Union University uses a machine gun as an example of a closed system.

Ah, the Union people try to bring up a faulty analogy also. I mean, they do not even place their machine gun on a cart within a vacuum but let us roll with it anyway.

What is being ejected from the end of a machine gun attached to a cart aside from the muzzle blast?

I'll give you three guesses, and the first two do not count.

[Realestfake]

You wrote a bunch of crap. Two people pushing off of each other is not an example of a closed system, period.

One single person is not a closed system, let alone two people.

You not *getting it* isn’t my problem. I will continue to engage because I believe you’re arguing in good faith.

Two shopping carts that were left in the parking lot are rolling towards each other. The two shopping carts collide. Do the two shopping carts form an open momentum system or a closed momentum system?

Step 1: Determine if there are any external forces acting on the momentum system.

There are no external forces acting on the system. The two shopping carts apply forces to each other, but nothing outside of the system applies a force.

Step 2: Identify the system as open or closed.

An open system will have external forces acting on it.
A closed system will have no external forces acting on it.
Since the shopping carts do not have any external forces acting on them when they collide, this is an example of a closed momentum system.

https://study.com/skill/learn/identifying-open-closed-momentum-systems-explanation.html

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

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

Literally has nothing to do with atmosphere.
Two shopping carts exert a force on one another. Two people exert a force on one another. Exploding fuel and rocket exert a force on one another.

[markjo]

If there is truly nothing that anyone can say or do to prove to you that a rocket (i.e., a closed system) can lose matter to its external environment (i.e., exhaust gas) then you need to stfu and never post any more the bs you love so well.

I agree wholeheartedly that a rocket can, and does, lose matter to its external environment.  I simply don't agree that the rocket does so as a closed system. 

If you can cite a credible scientific source that agrees with you that a closed system can lose matter to its external environment, then I will admit that I'm wrong and you were right all along.  If you insist on your interpretation of word "exchange" to mean that any transfer of matter must always be both ways at the same time, then your citation must include that as well.

That's what it takes to change my mind.  What does it take to change yours?

[Action80]

You wrote a bunch of crap. Two people pushing off of each other is not an example of a closed system, period.

One single person is not a closed system, let alone two people.

You not *getting it* isn’t my problem. I will continue to engage because I believe you’re arguing in good faith.

If you are going to "engage," then you should argue in good faith.

Writing, "Two people are closed system.", is not an argument in good faith.

It is bullshit, plain, pure, and simple.

Two shopping carts that were left in the parking lot are rolling towards each other. The two shopping carts collide. Do the two shopping carts form an open momentum system or a closed momentum system?

Irrelevant.

Step 1: Determine if there are any external forces acting on the momentum system.

There are no external forces acting on the system. The two shopping carts apply forces to each other, but nothing outside of the system applies a force.

Step 2: Identify the system as open or closed.

An open system will have external forces acting on it.
A closed system will have no external forces acting on it.
Since the shopping carts do not have any external forces acting on them when they collide, this is an example of a closed momentum system.

https://study.com/skill/learn/identifying-open-closed-momentum-systems-explanation.html

Irrelevant.

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

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

Literally has nothing to do with atmosphere.
Two shopping carts exert a force on one another. Two people exert a force on one another. Exploding fuel and rocket exert a force on one another.

Gaslighting bullshit.

[Action80]

If there is truly nothing that anyone can say or do to prove to you that a rocket (i.e., a closed system) can lose matter to its external environment (i.e., exhaust gas) then you need to stfu and never post any more the bs you love so well.

I agree wholeheartedly that a rocket can, and does, lose matter to its external environment.  I simply don't agree that the rocket does so as a closed system. 

If you can cite a credible scientific source that agrees with you that a closed system can lose matter to its external environment, then I will admit that I'm wrong and you were right all along.  If you insist on your interpretation of word "exchange" to mean that any transfer of matter must always be both ways at the same time, then your citation must include that as well.

That's what it takes to change my mind.  What does it take to change yours?

A rocket is a closed system.

It is a fact it loses matter to its external environment.

It takes in nothing in exchange from its external environment.

All facts.

[markjo]

A rocket is a closed system.

It is a fact it loses matter to its external environment.

It takes in nothing in exchange from its external environment.

All facts.

If that's true, then you shouldn't have any trouble citing a credible source that agrees with you.  If you can't do that, then don't bother replying.

[Realestfake]

You wrote a bunch of crap. Two people pushing off of each other is not an example of a closed system, period.

One single person is not a closed system, let alone two people.

You not *getting it* isn’t my problem. I will continue to engage because I believe you’re arguing in good faith.

Two shopping carts that were left in the parking lot are rolling towards each other. The two shopping carts collide. Do the two shopping carts form an open momentum system or a closed momentum system?

Step 1: Determine if there are any external forces acting on the momentum system.

There are no external forces acting on the system. The two shopping carts apply forces to each other, but nothing outside of the system applies a force.

Step 2: Identify the system as open or closed.

An open system will have external forces acting on it.
A closed system will have no external forces acting on it.
Since the shopping carts do not have any external forces acting on them when they collide, this is an example of a closed momentum system.

https://study.com/skill/learn/identifying-open-closed-momentum-systems-explanation.html

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

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

Literally has nothing to do with atmosphere.
Two shopping carts exert a force on one another. Two people exert a force on one another. Exploding fuel and rocket exert a force on one another.

Do explain how it’s “irrelevant” and “gaslighting bullshit”. I was kind of hoping for a more intelligent response, but that kind of non-response is perfectly fine with me.

I included a source describing how two X’s pushing each other is a closed system. Please include a source that states otherwise.

[Action80]

A rocket is a closed system.

It is a fact it loses matter to its external environment.

It takes in nothing in exchange from its external environment.

All facts.

If that's true, then you shouldn't have any trouble citing a credible source that agrees with you.  If you can't do that, then don't bother replying.

You have not posted anything that disagrees with it.

There are plenty of videos on this forum conclusively demonstrating rockets ejecting matter into the external environment.

It is established a rocket is a closed system.

[Action80]

Do explain how it’s “irrelevant” and “gaslighting bullshit”. I was kind of hoping for a more intelligent response, but that kind of non-response is perfectly fine with me.

I included a source describing how two X’s pushing each other is a closed system. Please include a source that states otherwise.

Your example is irrelevant to the op and not analogous to the operation of a rocket.

It is therefore gaslighting bullshit.

[Realestfake]

Your example is irrelevant to the op and not analogous to the operation of a rocket.

It is therefore gaslighting bullshit.

Before we go further, you’re dead serious right? Like you actually think this? I showed study material that directly contradicts what you claimed. Two objects exerting a force upon each other is clearly called a closed system.
Two carts pushing on each other is a closed system.
Two people pushing on each other is a closed system.
Exploding fuel and rocket pushing on each other is a closed system.
It is, in fact, analogous. This isn’t my opinion.

I’m not sure what properties of fuel and rockets makes the system immune to conservation of momentum.

[Action80]

Your example is irrelevant to the op and not analogous to the operation of a rocket.

It is therefore gaslighting bullshit.

Before we go further, you’re dead serious right? Like you actually think this? I showed study material that directly contradicts what you claimed. Two objects exerting a force upon each other is clearly called a closed system.

The example you provided has nothing whatsoever to do with your very own OP, which is, I remind you, Do rockets push off the air?

So, it doesn't directly contradict me, doesn't involve two people, doesn't involve rockets, and remains gaslighting bullshit.

Two carts pushing on each other is a closed system.
Two people pushing on each other is a closed system.
Exploding fuel and rocket pushing on each other is a closed system.
It is, in fact, analogous. This isn’t my opinion.

I’m not sure what properties of fuel and rockets makes the system immune to conservation of momentum.

I never stated anywhere rockets are immune to conservation of momentum.

For the final fucking time, two people are not a closed system. One person is not a closed system.

Neither people pushing off each other or shopping carts rolling in a fucking parking lot are analogous to the operation of a rocket.

You are simply gaslighting in your own OP.