Does Rocketry Work beyond Earth's atmosphere?

If NASA faked the moon landings, does the agency have any credibility at all? Was the Space Shuttle program also a hoax? Is the International Space Station another one? Do not dismiss these hypotheses offhand. Check out our wider NASA research and make up your own mind about it all.
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simonshack
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Re: Does Rocketry Work in the Vacuum?

Unread post by simonshack » Fri Jan 23, 2015 12:45 am

lux wrote:Simon, what part of the rocket pushes against the air behind it?
I will answer you with a question (or two, actually):

What part of these balloons propel those toy cars forward? And what is that 'part' pushing against?


full link: http://www.youtube.com/watch?v=1tNO0Meyups

lux
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Re: Does Rocketry Work in the Vacuum?

Unread post by lux » Fri Jan 23, 2015 1:20 am

I don't know. I'm asking you. :)

My question is: What part of a rocket pushes against the air behind it?

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Re: Does Rocketry Work in the Vacuum?

Unread post by simonshack » Fri Jan 23, 2015 1:36 am

*


NASA "PHYSICS": THICK AS A BRICK



My pen pal "P from the UK" just wrote me this brief / well-formulated point - which inspired me to make this post /and below graphic. I think we all know how NASA often uses 'clever, easy-to-understand-basic-physics" analogies when trying to explain the physics of how their rockets are propelled (up through the atmosphere - and beyond). I will hereby illustrate - using their own "children's-book" approach - how NASA's claims concerning rocket propulsion are wrong and, worse still, deliberately deceptive.
P from the UK wrote: As you are probably aware, NASA often use the analogy of a man sitting in a boat throwing bricks out the back to demonstrate how their rockets work; according to them the brick represents the rocket exhaust.

This is false.

In fact it is the man's hand that represents the rocket exhaust, whilst the brick represents the atmosphere.

You see what they did there?

The same principle can be applied to their 'Newton's Chariot' model as well.

I don't recall if this was pointed out in your 'rocketry in vacuum' thread; if so apologies, if not I hope it is useful in simplifying & clarifying the subject.
MAN IN DRIFTING BOAT
A man in a boat on a river is drifting downstream. He has three piles of bricks on board: B (pile of Big bricks), M /pile of Medium bricks) and S (pile of small bricks). He wishes to move upstream, so in order to combat the force of the constant waterflow (which we may think of as the constant Force of Gravity), he starts throwing his bricks overboard - in 'downstream' direction :
BoatPropulsion_trio.jpg
Fig.1: At first, his boat is drifting sideways, so he needs to overcome the strong DRAG pushing his boat downstream (think of it as the combined forces of gravity and atmospheric / aerodynamic drag which a rocket must overcome at sea level - in order to take off from the launch pad). He therefore starts throwing the BIG bricks overboard, as fast as he can. He is happy to see that the boat is being propelled upstream (much like a rocket will, in fact, lift off from the ground).

Fig.2: Luckily, the boat somehow straightens itself up (thus reducing the hydrodynamic drag - much like a rocket reaching thinner air / atmospheric pressure at higher altitudes) and, although he has run out of BIG bricks, he is now happy to see that he can keep moving upstream by throwing his MEDIUM-sized bricks off the aft of his boat / downstream.

Fig.3: But as he runs out of MEDIUM-sized bricks, the man is now distressed to see that, as he throws overboard his remaining pile of SMALL bricks (representing the very thin / ever-dwindling atmospheric pressure of a rocket approaching 100km altitude or so), the boat has stopped ascending and is now drifting downstream again - being now overwhelmed by the force of the waterflow (think "Force of Gravity").

And no - contrary to widespread popular myth - gravity does NOT abruptly cease to exist at 100km of altitude.
"At 100 km, you would officially be in space, yet the weight force of gravity would still be nearly the same."
http://sciencelearn.org.nz/Contexts/Sat ... ite-motion

In conclusion: NO known man-made propulsion system can make a rocket ascend beyond a certain altitude (100km or so) where the quickly dwindling atmosphere pressure drops to near-zero levels, or near-vacuum.
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Boethius
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Re: Does Rocketry Work in the Vacuum?

Unread post by Boethius » Fri Jan 23, 2015 1:47 am

As I have said before NASA's description of rockets moving through space defies basic principles of physics you can confirm in your own home with simple experiments.

NASA says the gas expanded in the nozzle of the rocket will push against the ship.

This is patently false and goes against the law that all forces immediately move towards the path of least resistance. As such gas would flow into the vacuum and not against the ship. If you place a live wire where a piece of metal touches a piece of rubber the electricity doesn't try to force itself through the rubber. It all immediately rushes into the metal. In the same way any gas expanded in the nozzle of a ship, which is exposed to the vacuum, will immediately be lost to the vacuum because the gas will always flow instantly to the area of lowest pressure, which is its path of least resistance. Gas always flows to the area of lowest pressure.

Note that it doesn't matter how much gas you expand in a vacuum. There will always be zero (0) pressure. Even locally. Why? Because each gas molecule that escapes into the vacuum never stops, is never caught by the one behind it and never catches up to the one in front. A billion, a trillion, a quadrillion molecules can all flow into the vacuum without ever slowing down or hitting each other thereby never increasing the pressure. NASA will tell you some molecules are hitting the side of the nozzle, no, the vacuum will suck all of the combustion. The lure of 0 pressure is too great to resist. As soon as the first molecule starts to expand into the vacuum, they all follow in an orderly sequence.

Also, gas cannot push against the ship and be pulled into space at the same time.

Here's an experiment you can do at home that replicates how NASA says rockets work. You'll see how wrong they are.
Take a small spring and on top of it place a small object, one that can be lifted by the spring. Now press the spring down onto the ground with the object on top and let it go. Mark the distance mentally. Now take the same spring and object, press it between your thumb and forefinger and let of both fingers at the same time, about chest high off the floor. Mark the distance. Which one went higher? According to NASA the compressed spring, which is a force, should press into the object even when off the ground the way they say gas presses up into a rocket. But wait, you might say, gravity is pulling the spring down. OK. I would have said that the spring presses down because that's the path of least resistance for the force of the expanding spring, but, anyway, you see how the spring can't both push up and down at the same time. Springs only work when one side is fixed against an object. That is not an aberration. It is the law of physics. One force, the expanding spring, cannot move downwards, whether enticed, pulled or a combination, and push upwards at the same time. Neither can electricity. Nor gravity. Nor expanding gas in the vacuum.

If you can't get your spring to push up when in mid-air, what's going to happen to your rocket when you try to release that gas into the vacuum?

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Re: Does Rocketry Work in the Vacuum?

Unread post by lux » Fri Jan 23, 2015 2:32 am

Isn't this the same Boethius who ragged on our forum & members over at LetsRoll? :o


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ADMIN (simon) : It doesn't matter, dear Lux. We will need all the brainpower / intellectual help we can get (from friends and 'foes' alike) in order to expose NASA - once and for all - for the stupid scam that it is.
<_<

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Re: Does Rocketry Work in the Vacuum?

Unread post by simonshack » Fri Jan 23, 2015 11:32 am

*


I received this mail today from Brandon - who prefers not to register to the forum.
Brandon wrote:I just wanted to add a few ideas on space fakery, and your recent update to the "Does rocketry work in a vacuum" thread inspired to at least forward you one of my thoughts.

It seems to be NASA's(and at least one of your member's) position that the rocket works by expelling mass out of the rocket and not by the exhaust gases pushing against the atmosphere.

The big problem I have with this is, if that was the primary/only mode of propulsion, you wouldn't need the rocked bell to begin with, heck you wouldn't even need to ignite the fuel, you could just let the fuel pumps spray the fuel mass out the back and have the same effect.

While I think about it, you wouldn't even need fuel, just use water like the earlier points about the water jet pack.
Of course, the idea of launching a rocket into space using just water is ridiculous, just as ridiculous as the idea that a rocket works in space or in the Earth's atmosphere via opposite and equal reaction when ejecting the fuel's mass.

Brandon

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Re: Does Rocketry Work in the Vacuum?

Unread post by simonshack » Fri Jan 23, 2015 1:20 pm

*

I am enjoying my ongoing e-mail conversations with my pen pal "P from the UK". Last night he sent me the below e-mail and he kindly gave me permission to publish it on the forum in its entirety:
P from the UK wrote:Hello again Simon.

I noticed you'd re-started the 'rocketry in vacuum' thread & began writing you an email that I hoped would help as Lux seemed to be having difficulty with my original, very brief, synopsis.

However, it rapidly degenerated into an epic rant decrying all NASA's rocketry claims & I was going to throw it away. But on reflection it's actually pretty funny, as well as containing some useful info amongst all the swearing, so I've decided to send you a slightly edited version.

I hope you take it in good humour; please bear in mind I've spent at least a week now trawling through NASA's surreal & rickety labyrinth of pseudo-scientific gibberish, trying to make sense of it all, & some of their madness must have rubbed off on me...

Anyway, here it is, from a few lines in:

"...perhaps if I'd stated "the man's hand, in the act of throwing the brick, represents the rocket exhaust" then things would be clearer.

After all, what are you doing when you throw a brick if not imparting pressure/thrust upon it?

But if you want an even simpler (& more practical) demonstration of how NASA's model of rocket propulsion is flawed, then take an ordinary firework rocket & attach a shield to it, just below the nozzle, thus blocking the exhaust from interacting with the atmosphere.

According to NASA it should still take off, as the work is being done within the rocket itself, but of course it will not; it will merely sit & sputter & go absolutely nowhere..

Indeed: sit, sputter, go nowhere; much like NASA apologists are wont to do when faced with the incontestable fact that the stupid fucking sci-fi wank-fantasy toys they worship so reverently cannot get anywhere near their beloved fucking sci-fi wank-fantasy 'outer space'.

Oh, and that's before we even consider the ineffable mystery of how NASA's rockets, with their dubious alleged maximum exhaust velocities of between 5000 & 10,000 mph can somehow accelerate so far beyond those speeds that they achieve the necessary escape velocity from Earth of 25,000 mph, let alone the velocity for low Earth orbit of 13,500 mph? It takes some serious Newton-abuse to justify such clearly impossible claims but since when have NASA given a flying fuck about the laws of physics?

And what about all the problems that heat from air-friction would cause at these mind-boggling speeds? The nose & wing leading edges of the SR-71 spy-plane had to be made of titanium to cope with the 500+C heat from travelling at 3500 mph, so what would happen to NASA's flimsy aluminium, mild steel & epoxy resin contraptions at 4 times that velocity? No amount of mathe-magic or algebra-cadabra could help them explain this because it is beyond bloody obvious to all but madmen, bastards & gorillas that EVERYTHING WOULD FUCKING MELT INTO A FIERY BALL OF FUCKING DEATH!!!

Further, & in the final analysis, anyone with a practical understanding of Free Expansion cannot help but realise that NASA's rockets simply must have huge problems operating efficiently in anything close to a hard vacuum of near infinite extent, whether fitted with a pointless bullshit 19th-century 'Choked-Throat'/'De Laval' nozzle or not.. Cos yeah, right, a 'combustion chamber' that's open to the vacuum; that'll work won't it? My fucking arse it will! Frankly, sticking go-faster stripes & spoilers on their shit-box rockets & shuttles would be just as effective.. maybe some furry fucking dice too, why not eh? "

Okay, I've cut it off there as the rest was just pure invective, obscenities & a howling, hate-filled diatribe about the implausible power-to-weight-ratio of the accursed space shuttle. I hope you found the above informative/entertaining anyhow & I guess you can at least now see why I don't consider myself a suitable candidate for forum membership.

Good night/morning, regards

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Re: Does Rocketry Work in the Vacuum?

Unread post by SteinUntStein » Fri Jan 23, 2015 3:05 pm

24,000 MPH. NY to Shanghai in 15 minutes! This figure just baffles me, and brings up further questions.

Allegedly, this speed is sustainable because of thrust and lack of resistance in space.
I want to know that if this is the case, why not just keep giving the alleged thrust until even higher speeds are achieved?
Seems the speed of light could be reached (and maintained, and whatever that speed REALLY is...) by giving just less than 10x the claimed thrust.
Wouldn't it be the case that if we kept accelerating we would continue achieve higher speeds? Why would we not yet have done so? Is fuel the problem?

Seems you need no better engines. If I am in my car and accelerate to 100 MPH in an atmosphere of no resistance, my car (Newton 1) will continue to go 100 MPH when I take my foot off the gas. Going 100, I can then give it full blast again, and thereby reach 200, at which time I can take my foot off the gas and coast, so on and on until I reach sped, or run out of gas.

A rocket in space could then, by this method, theoretically reach higher speeds than yet with minimal additional fuel. So why not just send out more fuel with the rockets, make bigger ships, take some thrust out with you?

Anyway Goddard was one of many scientists who also felt Newton's 2nd law inapplicable to motion in a vacuum. Boethius seems to think this law is being misapplied. Some still think the law itself is wrong, and has been confirmed by some to be wrong, when discussing things like inertial space.

Most of this is over my head but here you go:

http://www.earthtech.org/publications/puthoff_jbis.pdf

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Re: Does Rocketry Work in the Vacuum?

Unread post by SteinUntStein » Fri Jan 23, 2015 3:19 pm

http://alt.sci.physics.narkive.com/d0ri ... the-aether

[ADMIN: Hi, SteinUntStein, not to sound like a lawyer but you are required to introduce yourself here: http://cluesforum.info/viewtopic.php?f= ... start=1740

Thanks. -hp]

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Re: Does Rocketry Work in the Vacuum?

Unread post by hoi.polloi » Fri Jan 23, 2015 5:17 pm

The problem with the car analogy is that you have ground and a strong, direct form of friction to work with. The rockets should be beating 9.8 m/s^2 from the start because they have nothing to "climb" or "grab on to". This is what the ships are apparently doing according to the falsified videos of the launches, except that it's so torturously slow, they should be encountering far more internal friction problems than they talk about or care to explain with anything other than the faked videos, magic diagrams of vague ship guts and fairy-tales of secret formulas.

From my understanding, initial calculations of rockets (if you believe those, even) were saying they were going to have to be like skyscrapers to achieve the power and the heights they claim to have done with the toys they show on TV.

Correct me if I'm wrong.

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Re: Does Rocketry Work in the Vacuum?

Unread post by Boethius » Fri Jan 23, 2015 5:50 pm

It's time that we looked into how a rocket propels itself.

Before lift-off a rocket sits on a launching pad, which we will take to be immovable.

Upon ignition the rocket begins to expand Liquid Oxygen (the preferred fuel for NASA) which actually expands at about a 860-1 ratio, that is every liter of LOX ignited turns into 860 liters or .860 cubic meters of molecules. The expanded gas must push aside the existing air which was calmly sitting underneath the rocket. Since there are about 10000000000000000000000000 molecules in a cubic meter of air that one liter of LOX is going to have to do a lot of pushing to make room for itself, and push it does, pushing the air down and to the sides. Of course pushing down isn't going to work given the launch pad is immovable, so off to the sides the gas goes but that LOX which has just been expanded is slowed down by the effort it takes to push aside the air, and because the rocket is constantly igniting and expanding LOX the second wave smashes into the first wave, slowing down the second wave and then the third wave comes immediately behind, etc... until the pressure of the expanding gas under the rocket is higher than the pressure of the rocket (it's mass), causing the gas to push up on the rocket rather than down towards the launchpad. This is liftoff.

Once liftoff is achieved the rocket has two things pushing it up and two things slowing it's progress:
Momentum wants to keep the rocket moving forwards
The expanding gas wants to push up on the rocket because that's the lowest pressure area available to it
Wind resistance wants to slow it down, although the higher it goes the less resistance, plus it has an aerodynamic shape
Gravity wants to pull it back to earth, gravity is fairly constant within the atmosphere

If the rocket goes high enough the atmosphere will thin and the gas can easily escape out from behind the rocket without much hindrance depriving the ship of its propulsion. From that point on, or when it runs out of fuel, the rocket will begin to fall in an arc, back towards the earth. In fact, Werner von Braun was famous for calling the flight of a rocket "gravity's rainbow;" a rocket must go up very high to fall down very far away. The idea of a rocket cruising around like an airplane is a fantasy.

In other words a rocket moves through the atmosphere exactly like every other object that moves through the atmosphere, it creates high pressure underneath itself. And as such a rocket cannot possibly generate thrust in a vacuum.

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Re: Does Rocketry Work in the Vacuum?

Unread post by Selene » Fri Jan 23, 2015 6:40 pm

Nothing is more real than nothing
Samuel Beckett (1951)


Hi all,

what a great discussion and subject this is. Thumbs up to all contributors. I will try to shed my light on it and hopefully spark (unscientific pun intended) the discussion up again.

I started off reading the discussion on lux' and Heiwa's critical side to Boethius' attempts to convince the audience of his points. But, I have to say (and throw away another myth of mankind), he is right.

The crucial part is the quote above.

Space is not only a vacuum (the pressure discussion for the past 31 interesting and great pages), it is also absolutely stone cold. There's nothing.

Both P (pressure) and T (temperature) are nearly zero. At least, that's what most of the sciences agree upon, hopefully also the science unspoiled by NASA.

The ideal gas law P * V = n * R * T describes the key factors.
P = almost 0
T = almost 0
R = non existent (no gases in a vaccuum, only solids with such low T)
V = almost infinite (floating molecules into space)
n = ?

Boethius is right the rocket will not bring any thrust as there is no pressure law possible.

The comparison of simon on the water-powered funicular is great. The thrust produced by water in air is comparable to the thrust of hot air (rocket fuel) in a vacuum. It simply doesn't produce thrust.

But the Temperature is far more important. Remembering basic physics and chemistry in secondary education I recall that "molecules hardly move at near-zero temperatures".

Even if solar radiation causes temperatures to be higher on anything up there (a rocket, etc.) so on the sun-faced side of spacecraft and that heat can be transferred via conduction outside (the metal can) and convected inside (the pressurized cabin), there will always be a "shadow" side.

Material properties depend on temperature and at these extremely incredibly low temperatures everything becomes a solid and must become enormously fragile and break up in individual molecules.

As Boethius described the behaviour of the escaping "gas", like that is the interaction with the whole "solid" spacecraft with near-zero space as well.

What would happen?
  • Assuming the rocket gets enough thrust (E) and acceleration (a) to withstand Earth's gravity (g)
  • The rocket would reach lower and lower temperatures the higher it goes ( P -> 0, T -> 0, rho -> 0)
  • I do not know the temperature profile of the supra-atmospheric region, but with less and less air particles (rho), less and less heat (E, T) can be trapped
  • There has to be a limit as to where the rocket can travel based on both Temperature (material behaviour) and Pressure (thrust)
  • From there, and where this line actually is would be something to investigate, the rocket would simply fall back to Earth as there is no thrust to be produced to withstand the gravity
Even if the thrust would be no problem, at a certain temperature level everything desintegrates. It will break down in molecules, "floating" away in the vast nothingness of space.

And that is without counting the most enormous all-destructive types of radiation (E, lots of E) in space. If we don't know even 1% of our own oceans, how can we think we understand space? We have no way of going there and measuring which other kinds of unimaginable radiation is out there.

This makes space travel impossible and life on Earth comfortable. No alien could ever visit us in that ridiculous Star Trek spacecraft. :ph34r:

This is my thesis, and I realise I did not supply any links to the various points, but most of them are discussed in the previous pages anyway. Later on I will try to build the case better, but for now, this is my thought.

Selene

I have not the smallest molecule of faith in aerial navigation other than ballooning
William Thompson (Lord Kelvin) (1896)

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Re: Does Rocketry Work in the Vacuum?

Unread post by Maat » Fri Jan 23, 2015 7:54 pm

*
^ Excellent posts, Boethius & Selene! :)
simonshack wrote:*

I am enjoying my ongoing e-mail conversations with my pen pal "P from the UK". Last night he sent me the below e-mail and he kindly gave me permission to publish it on the forum in its entirety:
P from the UK wrote:Hello again Simon.

I noticed you'd re-started the 'rocketry in vacuum' thread & began writing you an email that I hoped would help as Lux seemed to be having difficulty with my original, very brief, synopsis.

However, it rapidly degenerated into an epic rant decrying all NASA's rocketry claims & I was going to throw it away. But on reflection it's actually pretty funny, as well as containing some useful info amongst all the swearing, so I've decided to send you a slightly edited version.

I hope you take it in good humour; please bear in mind I've spent at least a week now trawling through NASA's surreal & rickety labyrinth of pseudo-scientific gibberish, trying to make sense of it all, & some of their madness must have rubbed off on me...

Anyway, here it is, from a few lines in:

"...perhaps if I'd stated "the man's hand, in the act of throwing the brick, represents the rocket exhaust" then things would be clearer.

After all, what are you doing when you throw a brick if not imparting pressure/thrust upon it?

But if you want an even simpler (& more practical) demonstration of how NASA's model of rocket propulsion is flawed, then take an ordinary firework rocket & attach a shield to it, just below the nozzle, thus blocking the exhaust from interacting with the atmosphere.

According to NASA it should still take off, as the work is being done within the rocket itself, but of course it will not; it will merely sit & sputter & go absolutely nowhere..

Indeed: sit, sputter, go nowhere; much like NASA apologists are wont to do when faced with the incontestable fact that the stupid fucking sci-fi wank-fantasy toys they worship so reverently cannot get anywhere near their beloved fucking sci-fi wank-fantasy 'outer space'.

Oh, and that's before we even consider the ineffable mystery of how NASA's rockets, with their dubious alleged maximum exhaust velocities of between 5000 & 10,000 mph can somehow accelerate so far beyond those speeds that they achieve the necessary escape velocity from Earth of 25,000 mph, let alone the velocity for low Earth orbit of 13,500 mph? It takes some serious Newton-abuse to justify such clearly impossible claims but since when have NASA given a flying fuck about the laws of physics?

And what about all the problems that heat from air-friction would cause at these mind-boggling speeds? The nose & wing leading edges of the SR-71 spy-plane had to be made of titanium to cope with the 500+C heat from travelling at 3500 mph, so what would happen to NASA's flimsy aluminium, mild steel & epoxy resin contraptions at 4 times that velocity? No amount of mathe-magic or algebra-cadabra could help them explain this because it is beyond bloody obvious to all but madmen, bastards & gorillas that EVERYTHING WOULD FUCKING MELT INTO A FIERY BALL OF FUCKING DEATH!!!

Further, & in the final analysis, anyone with a practical understanding of Free Expansion cannot help but realise that NASA's rockets simply must have huge problems operating efficiently in anything close to a hard vacuum of near infinite extent, whether fitted with a pointless bullshit 19th-century 'Choked-Throat'/'De Laval' nozzle or not.. Cos yeah, right, a 'combustion chamber' that's open to the vacuum; that'll work won't it? My fucking arse it will! Frankly, sticking go-faster stripes & spoilers on their shit-box rockets & shuttles would be just as effective.. maybe some furry fucking dice too, why not eh? "

Okay, I've cut it off there as the rest was just pure invective, obscenities & a howling, hate-filled diatribe about the implausible power-to-weight-ratio of the accursed space shuttle. I hope you found the above informative/entertaining anyhow & I guess you can at least now see why I don't consider myself a suitable candidate for forum membership.

Good night/morning, regards
Simon,
Thank you so much for sharing your NA$A-nixing friend’s exceptionally eloquent invective. :lol: That just made my day! :wub:

Encore! I want to read his “hate-filled diatribe" about the "accursed space shuttle” now! (You already know what I think of those "flying" bricks <_< )

Some new terms for our “Clues Lexicon” too: mathe-magic, algebra-cadabra B)

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Re: Does Rocketry Work in the Vacuum?

Unread post by Selene » Fri Jan 23, 2015 8:14 pm

Maat wrote:^ Excellent posts, Boethius & Selene! :)
Thank you, Maat.

To add some info from Winkipedia:
Thermal properties of solids include thermal conductivity, which is the property of a material that indicates its ability to conduct heat. Solids also have a specific heat capacity, which is the capacity of a material to store energy in the form of heat (or thermal lattice vibrations).
http://en.wikipedia.org/wiki/Solid#Thermal
At absolute zero temperature, a crystal lattice lies in its ground state, and contains no phonons. A lattice at a non-zero temperature has an energy that is not constant, but fluctuates randomly about some mean value. These energy fluctuations are caused by random lattice vibrations, which can be viewed as a gas of phonons. (The random motion of the atoms in the lattice is what we usually think of as heat.) Because these phonons are generated by the temperature of the lattice, they are sometimes referred to as thermal phonons.

Unlike the atoms which make up an ordinary gas, thermal phonons can be created and destroyed by random energy fluctuations. In the language of statistical mechanics this means that the chemical potential for adding a phonon is zero. This behavior is an extension of the harmonic potential, mentioned earlier, into the anharmonic regime. The behavior of thermal phonons is similar to the photon gas produced by an electromagnetic cavity, wherein photons may be emitted or absorbed by the cavity walls. This similarity is not coincidental, for it turns out that the electromagnetic field behaves like a set of harmonic oscillators; see Black-body radiation.

http://en.wikipedia.org/wiki/Phonon#Thermodynamics
The laws of thermodynamics dictate that absolute zero cannot be reached using only thermodynamic means, as the temperature of the substance being cooled approaches the temperature of the cooling agent asymptotically. A system at absolute zero still possesses quantum mechanical zero-point energy, the energy of its ground state. The kinetic energy of the ground state cannot be removed.

Scientists have achieved temperatures extremely close to absolute zero, where matter exhibits quantum effects such as superconductivity and superfluidity.

http://en.wikipedia.org/wiki/Absolute_zero
NASA's "superengineering":
These hazards include the vacuum environment of space, temperature extremes ranging from -250 degrees Fahrenheit to 250 degrees Fahrenheit
http://en.wikipedia.org/wiki/ILC_Dover#Space_suits
-250 F = -156.67ºC or about 117 K ; 250 F = 121.11ºC or about 394 K
http://www.metric-conversions.org/tempe ... elsius.htm
The baseline temperature, as set by the background radiation from the Big Bang, is 2.7 kelvin (K)
http://en.wikipedia.org/wiki/Outer_space
How was your spacewalk, Neil an' tha boys? Chilly? :D

And a funny educational video:


full link: http://www.youtube.com/watch?v=QTYlC70VV_I

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Re: Does Rocketry Work in the Vacuum?

Unread post by Pilgrim » Sat Jan 24, 2015 12:08 am

Hi Selene, I fail to see what difference the temperature of "space" makes to the fact that Rockets cannot produce a thrust in a vacuum. A vacuum by its own definition has no matter to hold any temperature so is neither hot or cold and the fact the Rocket gases are hot and can only lose heat by radiation in a vacuum which takes time seems irrelevant to the immediate fact of whether they are hot gases or cold gases in terms of thrust produced by expelled mass. It should make no difference according to their logic. Of course I agree with the OP - only a reaction with another mass can produce an opposite reaction and Rocket fumes have nothing to react against in vacuum due to no pressure against anything as the vacuum offers zero resistance and will suck up all you have to offer with zero resistance so no "thrust" is possible.

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