People on skateboards.

Quote from: markjo on December 11, 2015, 07:44:23 AM

Are you saying that a tank is not a chamber?

I'm saying that you Lied about what sceptimatic wrote, dyslexia-boy.

The real crux of the matter is that Scepti understands that a force must be applied to a gas in order to accelerate it.  Why can't you?

The combustion chamber of a rocket is open to the near-infinite vacuum of space.

Therefore, no gas can even be meaningfully said to exist within it, let alone combust.

if I make a hole in a tank in vacuum i end up with a chamber open to infinite vacuum. are u saying that all the gas will imediately expand and that in a nano second i end up with an empty tank?

Are you people deliberately not grasping what Papa Legba is saying?
Read what he's just said in bold, which he's said numerous times and yet somehow you can't grasp it for two reasons, maybe.
1. Either you have no clue how to reply and are just jogging along as best you can.

2. You are deliberately trying to avoid what he's saying because you know that what he's saying is correct, so you tiptoe around it and make our he's saying something different.

The good part is that normal people see the truth, which is what counts.

Object B is the fuel.

Why can't you?

Why can't you learn to read my posts, cry-baby?

I ain't your errand-boy.

You're the crank who's arguing for the creation of pressure within an infinite vacuum.

You're the crank who's arguing that it's possible to push on nothing.

You're the crank who can't distinguish between One object & Two objects.

Do your own homework, crank.

Object B is the fuel.

LOL!!!

He is.

Am i correct in saying that vacuum can take out all the gas from an open chamber instantly?
No matter the dimension of the hole

Quote from: markjo on December 11, 2015, 08:16:28 AM

Why can't you?

Why can't you learn to read my posts, cry-baby?

I ain't your errand-boy.

You're the crank who's arguing for the creation of pressure within an infinite vacuum.

You're the crank who's arguing that it's possible to push on nothing.

You're the crank who can't distinguish between One object & Two objects.

Do your own homework, crank.

Quote from: sokarul on December 11, 2015, 08:45:54 AM

Object B is the fuel.

LOL!!!

He is.

Lol

Ever figure out how friction plays a part in work?

Lol

Ever figure out how friction plays a part in work?

Ever figure out how you can create friction against a vacuum?

He is The One.

Let's go over the facts again:

The combustion chamber of a rocket is open to the near-infinite vacuum of space.

Therefore, no gas can even be meaningfully said to exist within it, let alone combust.

Any gas introduced therein when the pressurised fuel tank leading to the combustion chamber is opened will simply expand freely into the enormous, zero-pressure vacuum, following the path of least resistance & doing no work whatsoever.

This will continue for as long as the fuel tank & chamber are open to the vacuum, until both exterior & interior pressures are equalised at zero.

It is a beautifully simple concept, fully supported by All the laws of physics, yet you 'round earthers' (lol!) just can't seem to grasp it...


Plus this:

You all claim that the recoil of a gun is a valid analogy for how a rocket works in a vacuum.

Here is why it is not:

With a gun you have object A, the mass of the gun; the expanding propellant, P, the gunpowder, sited between them; and object B, the mass of the bullet.

But with a rocket you ONLY have object A, the mass of the rocket,  & the expanding propellant, P, the fuel.

No object B, see?

Thus, you have removed the necessary recoil mass required to produce motion.

But we know a rocket DOES produce motion, don't we?

Ergo, some other mass MUST be taking the place of object B.

& the ONLY possibility for that other mass is the Atmosphere.

Ergo, NO atmosphere, NO motion; rockets CANNOT function in a vacuum.

Q.E.D.

No matter how hard you try to spin it, cultists, every child knows that You cannot Push on Nothing.

No maths required; only common sense.


Then there's the fact that you are all trying desperately to confine this 'debate' to the wrong branch of physics, i.e. Solid Mechanics rather than Fluid Mechanics...

Kinda dishonest of you, dontcha think?

Pressure-Gradient Forces, Gas Laws, Fluid Mechanics, Continuum Assumption & Joules Expansion are the areas I suggest neutral readers research.


Read & Learn!

Pressure-Gradient Forces, Gas Laws, Fluid Mechanics, Continuum Assumption & Joules Expansion are the areas I suggest neutral readers research.

Might I suggest you start reading these yourself as you still don't understand them....

Am i correct in saying that vacuum can take out all the gas from an open chamber instantly?
No matter the dimension of the hole

The vacuum doesn't take anything out.

I'll explain it, assuming your vacuum of space, or near vacuum as you prefer. Let's call it super low pressure.

We are going to go for opposites here just so you can understand how fast gases move into low pressure to fill the void, or try to.

We will start off with a glass thermos flask.
If you knock the welded glass bobble off your thermos, meaning you open up a SMALL hole, you hear a very sharp psst which takes about half a second or less.
What has  happened is the atmospheric sea level pressure has entered the low pressure area inside that thermos.

I want  you to think about this because it's relevant to what would happen in your low pressure space environment only the opposite way round and with your space being a massive area  for your gas to enter after it's released from your sealed tank to your supposed combustion chamber, because once it leaves that tank it it open to that low pressure area you call space.

It would pass go and not collect the 200, or to put it simpler; the gas would pass right through the combustion chamber and (as good as) freely expand into that low pressure HUGE area of space, encountering no resistance as it expands out into your space.
The only resistance to free expansion before it leaves the rocket nozzle is when it travels through restrictive pipes to reach that nozzle.
The thing is, even those pipes offer little resistance because there is nothing pushing back into the rocket as gases leave it, like there would be  at lift off on earth, which is why you cannot have free expansion and will encounter a resistance which is good old atmospheric pressure against the ejected gas.

On Earth you get ejected BURNING gas and in your space you get close to free expansion of that gas with almost immediate effect and no burning evident because for something to burn it has to meet a resistance.

The very simple way is to figure out why a candle goes out when placed in a jar. For the very same reason it would in a rocket if it was subject to extremely low pressure.

Quote

Pressure-Gradient Forces, Gas Laws, Fluid Mechanics, Continuum Assumption & Joules Expansion are the areas I suggest neutral readers research.

Might I suggest you start reading these yourself as you still don't understand them....

LOL!!!

Here's a post where you didn't even understand the meaning of the term 'evacuated':

I mean; look at this garbage:

Quote from: Mainframes on October 28, 2015, 06:25:30 AM

Quote

Free expansion is an irreversible process in which a gas expands into an insulated evacuated chamber. It is also called Joule expansion.

It is not that gas cannot do work in a vacuum. It is that gas does no work when expanding into an evacuated chamber because all of the effect net to zero.

What, exactly, is in that 'evacuated chamber' that the gas does no work whilst expanding into?

Could it be a vacuum?

Why yes; yes it IS a vacuum.

Thus, mainframes completely contradicts himself in one sentence!

& what 'because all of the net effect to zero' means is anybody's guess...

He does this all the time, yet expects us to believe he has a masters in science...

LOL!!!

Cool story bro...

What a BLITHERING fool...

BLITHERING, 'mainframes'; one of your favourite words, is it not?

How's the Reportfagging going btw?

for something to burn it has to meet a resistance.

what?!?!?!?!?!?!?!??!
seriously?

The very simple way is to figure out why a candle goes out when placed in a jar. For the very same reason it would in a rocket if it was subject to extremely low pressure.

candle goes out because it consume all the oxygen.


papa and scepti... how much do u think u know about fluid and thermo dynamics?

papa and scepti... how much do u think u know about fluid and thermo dynamics?

More than you know about English spelling & grammar, Illiteratus Rex...

Remember me saying this?

Also, could you please correct your atrocious grammar & spelling? It is distracting & makes you look thoroughly uneducated.
I will not ask again; you will be ignored if you persist in this evasive shabbiness.

Well, nothing's changed since then; so stop barking & get back in your kennel, Fido.

Are you people deliberately not grasping what Papa Legba is saying?

I grasp what Papa Legba is saying.  The problem is that what he's saying is wrong.

Quote from: markjo on December 11, 2015, 08:16:28 AM

Why can't you?

Why can't you learn to read my posts, cry-baby?

I do read your posts, but sometimes it's difficult to filter through all of your abusive and irrelevant shitspamming and LULZing. 

I ain't your errand-boy.

So you don't feel the need to support your outlandish claims with evidence?  Got it.

You're the crank who's arguing for the creation of pressure within an infinite vacuum.

Nope.  Just within a finite combustion chamber.

You're the crank who's arguing that it's possible to push on nothing.

Nope.  No matter how many times you say it, that isn't what I'm claiming.

You're the crank who can't distinguish between One object & Two objects.

Of course I can.  You're the one who can't seem to tell the difference between one system and the various objects that make up that system.

Do your own homework, crank.

I have.  Every time I look up free expansion and pressure-volume work, I find that they relate to closed systems such as gas in a piston.

Quote

for something to burn it has to meet a resistance.

what?!?!?!?!?!?!?!??!
seriously?

Yeah, seriously.

The very simple way is to figure out why a candle goes out when placed in a jar. For the very same reason it would in a rocket if it was subject to extremely low pressure.

Quote

candle goes out because it consume all the oxygen.

Consume all oxygen doesn't really explain what's really happened.

papa and scepti... how much do u think u know about fluid and thermo dynamics?

How much do you know and what would you like to tell us?

Let's hear it, what happens to the candle in the jar?

ps i asked what do u think u know? i just wanna your opinion, something like "i feel really comfortable with thermodynamics" or "i know the basics"
 

Another mighty shitpost from markjo.

Here's all we need to look at:

Quote from: Papa Legba on December 11, 2015, 08:54:26 AM

You're the crank who's arguing for the creation of pressure within an infinite vacuum.

Nope.  Just within a finite combustion chamber.

A 'finite combustion chamber' that's open to an Infinite Vacuum?

LOL!!!

Yeah; right... Cos that'll work!

Whatever; Carry On Lying!

Another mighty shitpost from markjo.

Here's all we need to look at:

Quote from: markjo on December 11, 2015, 12:03:12 PM

Quote from: Papa Legba on December 11, 2015, 08:54:26 AM

You're the crank who's arguing for the creation of pressure within an infinite vacuum.

Nope.  Just within a finite combustion chamber.

A 'finite combustion chamber' that's open to an Infinite Vacuum?

Correct.  Notice that I'm not saying that the combustion chamber is going to hold on to the gas for any length of time, just long enough for the fuel to burn and accelerate the resulting gasses.

Let's hear it, what happens to the candle in the jar?

ps i asked what do u think u know? i just wanna your opinion, something like "i feel really comfortable with thermodynamics" or "i know the basics"

You give me your examples of what happens and how it's happening, than I'll be more than happy to tell you what's happening as far as I'm concerned.

So tell me about your thermodynamics and give me some analogy as to how you think they work, plus tell me why the candle goes out under the jar. Try not to just say that oxygen gets used up. I want to know what's happening, so explain it all, then I'll tell you my thoughts.

sorry as far as i know there are no other explanation for the candle, but i'll be happy to hear yours

Quote from: luckyfred on December 11, 2015, 12:16:58 PM

Let's hear it, what happens to the candle in the jar?

ps i asked what do u think u know? i just wanna your opinion, something like "i feel really comfortable with thermodynamics" or "i know the basics"

You give me your examples of what happens and how it's happening, than I'll be more than happy to tell you what's happening as far as I'm concerned.

So tell me about your thermodynamics and give me some analogy as to how you think they work, plus tell me why the candle goes out under the jar. Try not to just say that oxygen gets used up. I want to know what's happening, so explain it all, then I'll tell you my thoughts.

Oxygen in the jar reacts with carbon and hydrogen in the candle wax to form carbon dioxide and water. When the is no more free molecular oxygen the combustion reaction ceases and the flame goes out.

Let's go over the facts again:

The combustion chamber of a rocket is open to the near-infinite vacuum of space.

Correct.

Therefore, no gas can even be meaningfully said to exist within it, let alone combust.

Incorrect.

Any gas introduced therein when the pressurised fuel tank leading to the combustion chamber is opened will simply expand freely into the enormous, zero-pressure vacuum, following the path of least resistance & doing no work whatsoever.

Whatever happened to the property of gasses expanding to fill the space available as it's moving through the combustion chamber?  How does the mass of the gas accelerate from zero in the tank to the speed of free expansion?  Do you understand that there is a difference between work being done by the gas and work being done on the gas?  Did you know that gas is a fluid that has viscosity and therefore it provides a certain amount of resistance to its own movement?

This will continue for as long as the fuel tank & chamber are open to the vacuum, until both exterior & interior pressures are equalised at zero.

Sure.

It is a beautifully simple concept, fully supported by All the laws of physics, yet you 'round earthers' (lol!) just can't seem to grasp it...

Except that you keep ignoring inconvenient laws of physics like mass flow and all 3 of Newton's laws of motion.

Plus this:

You all claim that the recoil of a gun is a valid analogy for how a rocket works in a vacuum.

That's because it is.

Here is why it is not:

Oh no, here we go again. 

With a gun you have object A, the mass of the gun; the expanding propellant, P, the gunpowder, sited between them; and object B, the mass of the bullet.

But with a rocket you ONLY have object A, the mass of the rocket,  & the expanding propellant, P, the fuel.

No object B, see?

Are you saying that the propellant isn't an object? 

Thus, you have removed the necessary recoil mass required to produce motion.

No, you fail to recognize it.  I'll give you a hint, it's the combustion gasses produced by burning the propellant.

But we know a rocket DOES produce motion, don't we?

Yes, we do.

Ergo, some other mass MUST be taking the place of object B.

Yes, the combustion gasses produced by burning the propellant.

& the ONLY possibility for that other mass is the Atmosphere.

False dichotomy.  You fail to consider the possibility that the rocket can supply its own reaction mass in the form of propellant.

Ergo, NO atmosphere, NO motion; rockets CANNOT function in a vacuum.
Q.E.D.

Nope.  Incorrect conclusion from a faulty premise.

No matter how hard you try to spin it, cultists, every child knows that You cannot Push on Nothing.

No one is saying that you can.

No maths required; only common sense.

What's wrong, are you afraid of math?  You'd be surprised at how much physics disagrees with common sense once you do the math.

Then there's the fact that you are all trying desperately to confine this 'debate' to the wrong branch of physics, i.e. Solid Mechanics rather than Fluid Mechanics...

Fluid Mechanics includes Mass Flow, which you keep saying doesn't apply.  Make up your mind, will you?

Kinda dishonest of you, dontcha think?

Not nearly as dishonest as your deliberate misrepresentation of our arguments and physics in general.

Pressure-Gradient Forces, Gas Laws, Fluid Mechanics, Continuum Assumption & Joules Expansion are the areas I suggest neutral readers research.

Read & Learn!

I suggest that you take your own advice and study up on Mass Flow as it applies to Fluid Dynamics.

What I find so laughable in all this is that poor Papa is left to carry the can. 
Pity there was not someone that does not have some sort of OCD when it comes to OBJECT B.

Every authority, essentially from Konstantin Tsiolkovsky (he omits the pressure difference term) on seems to be able to calculate the static thrust of a rocket, and seem to get the same result - except Papa, who lost his object B.  There was obviously NO link between these and NASA (no NASA!).
The basic thrust equation is written as

Where,

F =	static thrust (in N)
q =	mass flow (in kg/s)
Ve =	exhaust velocity (in m/s)
Pe =	exhaust pressure (in Pa/m^2)
Pa =	Ambient Pressure (in Pa/m^2)
Ae =	Exhaust area (in m^2)

Yes, I am harping on this simple equation because Papa Legba will not refute it, yet cannot say why the thrust of the rocket should fail as the ambient pressure falls towards zero!
A vacuum is NOT in some way magic.  It cannot suck anything out of the rocket.  The flow rate is determined by the nozzle characterictics and pressure differences.  Bernoulli might have a bit to say on this matter.  Look up a few references on "Choked Flow" - Choked flow is a compressible flow effect. The parameter that becomes "choked" or "limited" is the fluid velocity.

 
Pity there was not someone that does not have some sort of OCD when it comes to OBJECT B.

This argument is all about Object B; without it, your rockets are going nowhere.

As for convergent/divergent nozzles; fortunately for us, genuine engineers have to use them, for turbines etc, so the facts of their operation cannot be twisted & obscured by NASA pseudo-science.

And one of the facts of their operation is that they require back-pressure in order to work, a thing that cannot be achieved in an infinite vacuum.

Quote from: Papa Legba on December 11, 2015, 09:40:41 AM

No matter how hard you try to spin it, cultists, every child knows that You cannot Push on Nothing.

No one is saying that you can.

LOL!!!

Actually you all are; hence your insane claims that the rocket's own fuel mass is somehow Object B, and a rocket somehow 'pushes on itself' (lol!).

I suggest that you take your own advice and study up on Mass Flow as it applies to Fluid Dynamics.

If the Recoil Principle alone were the explanation for how rockets function, then the reaction mass needed for a rocket to travel any distance would approach Infinite...

Which doesn't seem very practical, does it?

*Yawn!*

Are we done here?

Good; then Carry On Lying!

Exhaust gases are object B. They have mass.

I said this:

Carry On Lying!

Then Blithering Blitherer 'mainframes' said this:

Exhaust gases are object B. They have mass.

Seems he took notice of my instructions; good little Blitherer!

But let's look again at how Walter 'mainframes' Mitty reacts when he gets called out on his Bullshit:

Ha ha ha lol!

You don't even understand the composition of matter and how gases behave. Muppet.

i have a degree and you clearly don't. I can feel the jealousy oozing from your every pore. Sorry little boy, go back to masturbating in your parents basement.

Teh lulz!!!

Toodle-pip, Blithering Blitherer & obvious Fraud 'mainframes'.

If the Recoil Principle alone were the explanation for how rockets function, then the reaction mass needed for a rocket to travel any distance would approach Infinite...

why?

Are we done here?

Good; then Carry On Lying!

NO, you say a rocket cannot work in a vacuum, but
You still have NOT answered this simple question!  At what ambient pressure does a rocket fail to work?
If you understand rockets so well you should have no difficulty answereing that one.
BTW Konstantin Tsiolkovsky was hardly influenced by NASA, he DIED in 1935, yet his simplified rocket equation was
F = q.V_e  where:

F =	static thrust (in N)
q =	mass flow (in kg/s)
Ve =	exhaust velocity (in m/s)

Ambient pressure does not even come into it!
PS I know know what a liar is - anyone who disagrees with Papa.

At what ambient pressure does a rocket fail to work?[/b]

LULZ!!!

Obvious lurker/stalker is obvious...

Well, I guess that'd depend on the nozzle design, wouldn't it, lurky/stalky youtube troller Rab Downunder..?

But unless NASA can design a nozzle that is Infinitely wide, or provide an Infinite amount of 'reaction mass' (lol!), then their shpayze-rokkits won't be working too well.

*Yawn!*

Can we at least get a straight answer from all you shpayze-tards as to whether you think the EU are lying to their schoolchildren with this?





And whether Popular Mechanics were lying to their readers with this?





It may help clear matters up?

Thank you please!