People on skateboards.

Shouldn't be a simple question to answer by a couple of knowledgeable people like u two?

Quote from: nodnyl on December 13, 2015, 08:54:41 AM

Quote from: sokarul on December 13, 2015, 08:43:23 AM

Do you have a thing educated to say or are you just going to be stupid?

You're getting very defensive about this.

About what?

You know what.

Ps I've never claimed it has been written by a journalist and i have no idea from whom they've been written

OK,  I was going to keep away from this, but I can't have Luckyfred blamed for my "indisgression"! I blamed journalists for claiming that jet engines "push on the air" when they are really "reaction" devices!
My whole point was that I would not really expect to get 100% accurate scientific information from either Popular Mechanics or some information sheet for school children - I have seen enough of how writers can, with the best of intentions, distort information.  I would not be too critical of them, they may be much better trained than say newspaper journalists, but they are not always highly knowledgeable in all the wide range of topics they have to write about.

I would rather trust MIT or some institution like that than these "popular" publications, even though they do make interesting reading.  Papa legba will of course ask if I think they are liars, well no I definitely do not!

My other point has been that I have been vainly trying to get papa legba to indicate just how high we have to go for a rocket to "suddenly" fail!
It can't be below 85,000 ft (air pressure 25.05 mbar) as this is the service ceiling of the SR-71A, so a jet engine works here.
I doubt it can be below 123,523 ft (air pressure 4.68 mbar) as the MiG E-266M jet plane has flown that high.
What about 314,000 ft (air pressure 0.00117 mbar)? The X-15, a  winged rocket plane, has reached this altitude.
Are we there yet?  So, does a rocket work at 300,000 ft - almost the "edge of space"?

A simple yes or no on that point would be a start.

PS I have not mentioned the "v" word.  BTW, even at the 100 km altitude of the Kármán line, we do not strictly have a "you know what".

OK,  I was going to keep away from this, but I can't have Luckyfred blamed for my "indisgression"!

Before we indulge your pseudo-scientific blather any further, please define the word 'indisgression'.

We are already painfully aware of luckyfred's fluency in Gibberish; has he perhaps been giving you lessons?

Or is it a word that you learned from your relentless & unwelcome youtube trolling sessions?

Thank you please!

Quote from: rabinoz on December 14, 2015, 03:54:56 AM

OK,  I was going to keep away from this, but I can't have Luckyfred blamed for my "indisgression"!

Before we indulge your pseudo-scientific blather any further, please define the word 'indisgression'.
We are already painfully aware of luckyfred's fluency in Gibberish; has he perhaps been giving you lessons?
Or is it a word that you learned from your relentless & unwelcome youtube trolling sessions?
Thank you please!

If you cannot understand what I said, that's not my fault.  And NO I did not even need a spell checker to spell "indisgression"!  But, I was the one who labelled the writers of those articles as journalists, not Luckyfred, so I tried to explain to you why I did that.  Sorry if my words were too long!
If you call words like "altitude", "air pressure", "Kármán line" and "service ceiling", etc "pseudo-scientific blather", I could try to find words in the First Grade Primer that you might understand - but I won't.  what I asked you was completely unambiguous, so why no answer?  Sceptimatic maybe could explain it to you.

PS So you regard pointing out people's woeful understanding of the Globe Earth trolling. You know, the rubbish put out about planes heading into space on a globe and aircraft attitude indicators "proving" a flat earth - all simply demonstrating an abysmal understanding of how planes fly and what aircraft instruments actually do.
If you don't like it, tough cheese as they say in the classics!

If you cannot understand what I said, that's not my fault.

So if I cannot understand a word that you just made up it's MY fault?

LOL!!!

Yet another Humpty Dumpty rears it's cone-shaped head!

This is awesome; you slapstick raown derfers never cease finding new ways to amaze & amuse...

So if I cannot understand a word that you just made up it's MY fault?

indiscretion

n.
1. lack of discretion; imprudence.
2. an indiscreet act, remark, etc.
[1300–50; Middle English < Late Latin]

rabinoz when was your 700th birthday or is it still coming up?

Also, it seems you need to discover the ignore function on the Forum, it does amazing things to the quality of posts

Quote from: markjo on December 13, 2015, 03:16:15 PM

Very simple.  Jump up into the air.

The floor is object A

You are object B

Where is the propellant?

I can't believe you wrote this.

I, on the other hand, can believe that you didn't answer the question,

But okay; so, the 'rocket-man' in your insane analogy has launched himself from the ground.

How does he now keep going upwards, to 'shpayze'?

  Are you a psycho or just an idiot? 

When did I say anything about him going into space?

'Indisgression' & 'Indiscretion' are two different words, in case you haven't noticed...

Wtf is wrong with you?

And markjo; are you saying that rockets contain no propellant?

Or is the simple principle of the release of energy through Contraction & Expansion simply beyond you?

*Yawn!*

Lastly, I have no idea where this came from:

PS So you regard pointing out people's woeful understanding of the Globe Earth trolling. You know, the rubbish put out about planes heading into space on a globe and aircraft attitude indicators "proving" a flat earth - all simply demonstrating an abysmal understanding of how planes fly and what aircraft instruments actually do.
If you don't like it, tough cheese as they say in the classics!

I have never stated any of the above; I suggest rab downunder's brain is broken...

Perhaps we should call a WAAAAAmbulance?

At any rate, it at least helps explain how he gained his 'most-blocked youtube troll' title.

Toodle-pip, Losers!

can papa or sceptimatic explain how does convergent/divergent nozzle work, please?

can papa or sceptimatic explain how does convergent/divergent nozzle work, please?

No they cant!

Oh wait, I dont think you where asking me.

And markjo; are you saying that rockets contain no propellant?

No.  I'm saying that rockets contain their own reaction mass (propellant).

Or is the simple principle of the release of energy through Contraction & Expansion simply beyond you?

Not at all.  I'm saying that the energy (propellant) can come from the reaction mass (person jumping).

Astounding!

You can't even read the very links that you provided.

You just ask me to explain them to you...

Slapstick Circle-jerk Troll-japery Intensifies!

Anyhoo; back to rockets, Newton's Laws & Free Expansion:

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.

Oh; & Thermodynamics too - thanks for that, markjo!

P.s:

Quote from: Papa Legba on December 14, 2015, 05:35:20 AM

Or is the simple principle of the release of energy through Contraction & Expansion simply beyond you?

Not at all.

Really?

When the man jumps, do his legs contract then expand?

*YAWN!*

Where did popular mechanic say jet engine push off the atmosphere? Do you understand the word "off" and "against" mean different things?


Also the fuel is Object B

Lol

Quote from: markjo on December 14, 2015, 06:20:17 AM

Quote from: Papa Legba on December 14, 2015, 05:35:20 AM

Or is the simple principle of the release of energy through Contraction & Expansion simply beyond you?

Not at all.

Really?

When the man jumps, do his legs contract then expand?

The mass of the man is supplying the force needed to push against the mass of the ground in the same way that the mass of the expanding propellant is supplying the force needed to push against the mass of the rocket.

*Yawn!*

When the man jumps, do his legs contract then expand?

Everybody already knows the answer; it'll just be fun watching you squirm...

*Yawn!*

When the man jumps, do his legs contract then expand?

*sigh*  Yes.

So, a man jumps by utilising the energy provided through the contraction & expansion of his legs against the ground.

Yes?

So, a man jumps by utilising the energy provided through the contraction & expansion of his legs against the ground.

Yes?

Yes.  However, are you suggesting that a man and his legs are 2 different objects?

Quote from: Papa Legba on December 14, 2015, 06:47:57 AM

So, a man jumps by utilising the energy provided through the contraction & expansion of his legs against the ground.

Yes?

Yes.

So, if we removed the ground and replaced it with Nothing, would the man still be able to jump?

Quote from: markjo on December 14, 2015, 06:49:07 AM

Quote from: Papa Legba on December 14, 2015, 06:47:57 AM

So, a man jumps by utilising the energy provided through the contraction & expansion of his legs against the ground.

Yes?

Yes.

So, if we removed the ground and replaced it with Nothing, would the man still be able to jump?

Of course not, because you've removed object A.  As you well know, action/reaction pairings require 2 objects.

Astounding!

You can't even read the very links that you provided.

You just ask me to explain them to you...

u're referring to my question?
have u read them? they seem in contrast with what u claim.
i just want to compare them with your claims but first u have to explain how do nozzles work according to u

Of course not, because you've removed object A.  As you well know, action/reaction pairings require 2 objects.

Good.

So, the man, his legs, leg-bones & muscles are all ONE object, using stored energy to create a Force by expanding against a SECOND object, i.e. the ground.

Yes?

Lol

This is going to be good. He will explain it to you and then you will claim object B is the air.

Lol

Uneducatedness

Quote from: markjo on December 14, 2015, 07:05:26 AM

Of course not, because you've removed object A.  As you well know, action/reaction pairings require 2 objects.

Good.

So, the man, his legs, leg-bones & muscles are all ONE object, using stored energy to create a Force by expanding against a SECOND object, i.e. the ground.

Yes?

Yes, in exactly the same way that the expanding (burning) propellant is ONE object using stored energy to create a force by expanding against a SECOND object, i.e. the combustion chamber.

Lol

This is going to be good. He will explain it to you and then you will claim object B is the air.

Lol

Uneducatedness

Stop ogling sheep.

Yes

Good.

Now let us look at a rocket on its launch pad, with its fuel stored inside.

Is it fair to say that this, too, is ONE object, in the same way that a man, his leg-bones, muscles, stored energy etc, are ONE object?

Quote from: markjo on December 14, 2015, 09:02:26 AM

Yes

Good.

Now let us look at a rocket on its launch pad, with its fuel stored inside.

No, let's not.  We are discussing rockets in space, not rockets on launch pads.

Also, I like how you conveniently ignored the part of my post that proves that the propellant can be object B.

No, let's not.

LULZ!!!

Markjo's bottled it - Victory to Legba again!

Semper Fi, girlfriend!

you conveniently ignored the part of my post that proves that the propellant can be object B.

Actually, I ignored everything you said that was not a simple 'Yes' or 'No'.

Whatever; the only thing you've proved today is what a gutless fraud you are.

Good work ex-mod, sock-puppeteer & forum manipulator 'markjo 28000'

Toodle-pip, LOSER!

Just keep talking, kid. You are wrong. Nothing more.