.....

Quote from: ThinkingMan on November 30, 2012, 10:56:11 AM

Quote from: sceptimatic on November 30, 2012, 10:53:22 AM

Quote from: ThinkingMan on November 30, 2012, 10:36:42 AM

Quote from: sceptimatic on November 30, 2012, 10:20:55 AM

Quote from: ThinkingMan on November 30, 2012, 10:13:50 AM

Quote from: sceptimatic on November 30, 2012, 10:09:10 AM

Quote from: robertotrevor on November 30, 2012, 10:00:29 AM

Quote from: sceptimatic on November 30, 2012, 09:57:32 AM

Quote from: robertotrevor on November 30, 2012, 09:51:55 AM

The explosion itself its already creating force to create expansion. The force making the rocket move is that expansion against the rocket, mass causing pressure against mass.
The rocket moves because of the expansion of gasses against the rocket, not against the vacuum.

The point is where the explosion would be. Is not an accurate representation of a rocket, just to show the forces.

This is exactly you saying that the rocket pushes against itself with the exhaust having no part in it.
It's so silly , it's actually scary to think people believe this.

You don't get it, the exhaust against vacuum does nothing, but there are also gases moving against the rocket. The gasses push the rocket so it moves, is not the rocket against the rocket because this gases are not attached to the rocket and are constantly leaving it.

Have a word will you.

The gases cannot just push the rocket without an external force to act against.
On Earth it has that. It's called atmosphere.
In space, it's rendered a simply empty tin can.

Why don't you push against the atmosphere and see how far you get?

Give me a helicopter and I will.

A helicopter does not push anything. It's blades are designed to create a force known as lift, which is not the way a rocket works. Rockets do not have spinning rotors. They have a combustion chamber... and it has been explained how that works.

EDIT: Time for me to fade back into the background.

How do you think the blades create lift?

Downward force that's how.

Okay, I'll fade away after this brief response. They create light from the shape of the blade and the way it moves laterally through the air, which creates a "pillow" of air underneath the blade. If the blade is angled properly and moving the right speed, it will live the craft underneath it. It works the same way with airplane wings. You're not going to tell me that wings create a downward force are you? Good, because that would just be ridiculous.

I'll tell you what.

Just fade away , because you talk in riddles.

Riddle? I understand it, it is concatanted and logical, if a little ungrammatical; are you sure you don't have problems thinking straight?

In case you are indeed seeking enlightenment, in addition to 29silhoutte's here is another experiment for you to try or just watch someone else trying that illustrates the concepts you are having issues with

Google 'Hero's Engine'

#" class="bbc_link" target="_blank" rel="noopener noreferrer">Home-built Hero of Alexandria steam engine, work in progress.

This is a rudimentary device that when water is heated it turns to steam and expands - the gas (steam) expands from the higher pressure environment inside the sphere into the lower pressure environment outside the sphere and provides force and therefore propulsion.

You could perform that same experiment in a vacuum - just would need to get a heat source that would work in that environment.

Quote from: 29silhouette on November 30, 2012, 10:58:11 AM

Hey Sceptimatic, despite saying bye earlier, I have an experiment and visual aid for you to try should you feel up to it.

Unlike the vacuum chamber, or even the balloons, this one should take minimal resources and setup time.

1. Take an empty, lidless shoebox.

2. Place both hands in the shoebox.

3. Move hands outward and press against the ends (simulating internal pressure, i.e. combustion, etc).

4. Note that while applying internal pressure to both ends, the box does not move either direction. 

5. Now, cut an opening in one end.

6. Again place your hands in the box and begin applying pressure outward against the ends.

7. Note that one hand exits the box through the opening and is pushing against nothing, while the other hand is pushing the box and moving it.

Obviously this only simulates pressure to the front and back, as you're not applying equal force to the bottom, sides, or (open anyway) top.

And what is this supposed to prove?

Here's an experiment for you.

get a shoe box and cut the right end away from it, then place both hands inside it, then shove your right hand towards the open end, but in doing so, follow it out with your left hand.

Does the box move ?..No?

That's space for you.

in your model what stands in for the internal pressure? force doesn't just go in one direction, no matter how you might wish it does.

Quote from: Mantaxi on November 30, 2012, 11:05:45 AM

Quote from: sceptimatic on November 30, 2012, 11:01:53 AM

Quote from: ThinkingMan on November 30, 2012, 10:56:11 AM

Quote from: sceptimatic on November 30, 2012, 10:53:22 AM

Quote from: ThinkingMan on November 30, 2012, 10:36:42 AM

Quote from: sceptimatic on November 30, 2012, 10:20:55 AM

Quote from: ThinkingMan on November 30, 2012, 10:13:50 AM

Quote from: sceptimatic on November 30, 2012, 10:09:10 AM

Quote from: robertotrevor on November 30, 2012, 10:00:29 AM

Quote from: sceptimatic on November 30, 2012, 09:57:32 AM

Quote from: robertotrevor on November 30, 2012, 09:51:55 AM

The explosion itself its already creating force to create expansion. The force making the rocket move is that expansion against the rocket, mass causing pressure against mass.
The rocket moves because of the expansion of gasses against the rocket, not against the vacuum.

The point is where the explosion would be. Is not an accurate representation of a rocket, just to show the forces.

This is exactly you saying that the rocket pushes against itself with the exhaust having no part in it.
It's so silly , it's actually scary to think people believe this.

You don't get it, the exhaust against vacuum does nothing, but there are also gases moving against the rocket. The gasses push the rocket so it moves, is not the rocket against the rocket because this gases are not attached to the rocket and are constantly leaving it.

Have a word will you.

The gases cannot just push the rocket without an external force to act against.
On Earth it has that. It's called atmosphere.
In space, it's rendered a simply empty tin can.

Why don't you push against the atmosphere and see how far you get?

Give me a helicopter and I will.

A helicopter does not push anything. It's blades are designed to create a force known as lift, which is not the way a rocket works. Rockets do not have spinning rotors. They have a combustion chamber... and it has been explained how that works.

EDIT: Time for me to fade back into the background.

How do you think the blades create lift?

Downward force that's how.

Okay, I'll fade away after this brief response. They create light from the shape of the blade and the way it moves laterally through the air, which creates a "pillow" of air underneath the blade. If the blade is angled properly and moving the right speed, it will live the craft underneath it. It works the same way with airplane wings. You're not going to tell me that wings create a downward force are you? Good, because that would just be ridiculous.

I'll tell you what.

Just fade away , because you talk in riddles.

Riddle? I understand it, it is concatanted and logical, if a little ungrammatical; are you sure you don't have problems thinking straight?

To be honest, I'm obviously not thinking straight because I've now replied to a few of your attempted put downs, so now I'll think straight and simply give you an ultimatum.

Either debate your points and you will get replies. After you apologise.

Or

Carry on with your attempted put downs and allow me to test out the ignore feature.

Your choice.

The silent tretament does not bother me.

Quote from: Kendrick on November 30, 2012, 11:09:08 AM

In case you are indeed seeking enlighteningment, in addition to 29silhoutte's here is another experiment for you to try or just watch someone else trying that illustrates the concepts you are having issues with

Google 'Hero's Engine'

#" class="bbc_link" target="_blank" rel="noopener noreferrer">Home-built Hero of Alexandria steam engine, work in progress.

This is a rudimentary device that when water is heated it turns to steam and expands - the gas (steam) expands from the higher pressure environment inside the sphere into the lower pressure environment outside the sphere and provides force and therefore propulsion.

You could perform that same experiment in a vacuum - just would need to get a heat source that would work in that environment.

And what heat source would work in that environment?

Anything that wouldnt require a flame - an electric or chemical heating element would work.

Edit:  something else for your brain to chew on - if you decide that this experiment only works because the expanding gas (steam) is pushing against the friction of the atmosphere - do you think performing this experiment in a higher pressure environment - the atmosphere being more dense - would make the sphere spin faster or behave any differently?

Quote from: 29silhouette on November 30, 2012, 10:58:11 AM

Hey Sceptimatic, despite saying bye earlier, I have an experiment and visual aid for you to try should you feel up to it.

Unlike the vacuum chamber, or even the balloons, this one should take minimal resources and setup time.

1. Take an empty, lidless shoebox.

2. Place both hands in the shoebox.

3. Move hands outward and press against the ends (simulating internal pressure, i.e. combustion, etc).

4. Note that while applying internal pressure to both ends, the box does not move either direction. 

5. Now, cut an opening in one end.

6. Again place your hands in the box and begin applying pressure outward against the ends.

7. Note that one hand exits the box through the opening and is pushing against nothing, while the other hand is pushing the box and moving it.

Obviously this only simulates pressure to the front and back, as you're not applying equal force to the bottom, sides, or (open anyway) top.

And what is this supposed to prove?

Here's an experiment for you.

get a shoe box and cut the right end away from it, then place both hands inside it, then shove your right hand towards the open end, but in doing so, follow it out with your left hand.

Does the box move ?..No?

That's space for you.

So you're saying there's no pressure inside the box, or rocket combustion chamber/nozzle pushing against the inside walls?  1. Yes or no.
 
1. If no, then there will be a hand/pressure pushing forward inside forcing movement.

1. If yes, and movement of the box relies only on my hands exiting the opening against the atmosphere, then if I move my hand fast enough against the resistance of the air, the box will move correct?  2. Yes or no.

2. If yes, by all means give it a try.

2. If no, then I guess it needs some pressure pushing forward from inside. (Hence, the hand creating pressure against the inside, or rocket fuel combustion creating pressure against the inside, regardless of air pressure, or lack there of, outside)

Quote from: Kendrick on November 30, 2012, 11:09:08 AM

In case you are indeed seeking enlighteningment, in addition to 29silhoutte's here is another experiment for you to try or just watch someone else trying that illustrates the concepts you are having issues with

Google 'Hero's Engine'

#" class="bbc_link" target="_blank" rel="noopener noreferrer">Home-built Hero of Alexandria steam engine, work in progress.

This is a rudimentary device that when water is heated it turns to steam and expands - the gas (steam) expands from the higher pressure environment inside the sphere into the lower pressure environment outside the sphere and provides force and therefore propulsion.

You could perform that same experiment in a vacuum - just would need to get a heat source that would work in that environment.

And what heat source would work in that environment?

Well, the burning of liquid oxygen and liquid hydrogen in a combustion chamber, for one.

Sceptimatic - I really cannot get my head around your complete inability to understand a a concept as simple as a rocket.

Fuel & oxygen combine, liberating large amounts of energy.  This causes extreme heating & expansion of the resulting gas.  The gas escapes at high speed through the cunningly designed hole in the expansion chamber, and the law of conservation of momentum means that an equal & opposite amount of momentum is imparted to the rocket - sending it the other way.

My 11 yearold son has no trouble understanding this.

First of all, let's start with the fire hose on Earth and what is acting on it and why it goes mental if left alone.
Once the pump is started, it forces the water through the hose at pressure and the faster the pump, the faster the pressure.

Pressure isn't a speed. 

If you have the hose nozzle turned off, the water will rush into that hose and fill it and then the hose would be laid there doing nothing.

Correct

Pick up that hose and open the nozzle and you feel the pressure of the water push back against you. The water is flowing in "one " direction only and that is away from you, against two acting forces, which are the the atmosphere and gravity.

The water is indeed flowing only one direction and yes it would act against atmosphere and gravity.  REMEMBER THIS.

The faster you push the air away, the faster the air comes back which creates a force against you,

That isn't really worded correct but the idea is correct, yes air resistance exists.   

Naturally you get told that it's just the mass of the water alone that does this, yet if you were to walk into a thin roofed alley way with the same hose , you will find that you would be blown back onto your arse because the water is compressing the air inside that alley meaning that the air  is now acting like a...... for want of a few better words, an "air spring"..

I'm not quite sure what you are trying to say, but the water coming out does disrupt the air.  But air and water don't force each other as much as you think. If you turn a bottle of water upside down, air can't hold the water in. Air resistance slows down the water after it leaves the hose.  Air resistance does not effect the hose.     

All that the water in the hose is doing is creating a friction against the air which is why you are forced back.

Untrue.  As you said before, water coming out is impeded by air.  As you said, atmosphere applies a force to the water.  The water is not the hose.  You said this yourself. Although atmosphere has little force on the water coming out of the hose.  In a vacuum, the water would be unimpeded by air and could actually come at a little faster. Air resistance slows down the water after it leaves the hose.  Air resistance does not effect the hose.         

Picture it like this.
Go and run down an alley that is closed off at the end and that it is exactly the same width as your shoulders and 1 inch above your head height  and roofed, meaning you can run and your shoulders are mildly touching the sides and not really impeding your movement.

Run as fast as you can towards the wall at the end and you will find that it gets harder and harder to run the closer you get to the end, because what you are doing is compressing the air.

Not entirely true since air can still go around you. But yes, air can be compressed in a confined space. Key word, confined.  The hose in the video is not in a confined space.  If you take your same experiment but do it in a vacuum(yes I know you can't really do that), does that mean you can't run in the ally, or you can run easier in the ally? You could run easier, your force has no opposite force acting on it so you have no trouble hitting the wall.

When a hose gets left on the floor with the nozzle open, it acts like a mental snake because it is working against air pressure which will push it from side to side because the hose is uneven against it so it pushing the air in all directions making the hose act in this manner.

Incorrect still.  As you said, air acts on the water. The hose acts like a "mental snake" because water is leaving the hose. As you said if no water is leaving the hose, the hose doesn't move. 

You take away the air/friction against this hose and it would simply shoot out its water in the direction it's facing and would not act in a wriggling snake like manner.

You said the air is against the water. Why are you changing your mind? 

The only reason friction/air is denied in experiments is because it would immediately kill off space travel and they know this, so Newtons law comes into play but Newtons law is manipulated to factor in space.

Air friction is not denied in experiments. If I shoot a bullet at a target, air will slow the bullet down as it travels.  If no air is present to slow the bullet down, the bullet will not slow down. Noone denies this.

You are just confused. Here is another thought.
A .308 caliber bolt action rifle will have more felt recoil than a .223 caliber rifle. A .308 bullets are around 160 grains and velocity at the muzzle around 2,700 ft/s.  A .223 bullet with a mass of 55 grains will have a velocity around 3,200 ft/s.  Why is it the faster bullet has less recoil?  As you say, it "compresses the air faster". 
 

rockets, satellites, rover, space stations etc, have been sent to space. You choose not to believe it. Maybe you don't want to understand it, maybe you can't, maybe a little of both. But that doesn't change the facts or the physic laws.

I'm certainly not confused. I'm 100% certain rockets will not work in space.

What you show me on Earth will not work in the vacuum of space, which is what you people cannot comprehend.

How are you 100% certain you are correct in stating that rockets will not work in space?

I'm certainly not confused. I'm 100% certain rockets will not work in space.

What you show me on Earth will not work in the vacuum of space, which is what you people cannot comprehend.

If you think that Newtons 3rd law somehow fails to operate in low pressure environments, then you are certainly confused about something.

Quote from: Kendrick on November 30, 2012, 03:58:19 PM

Quote from: sceptimatic on November 30, 2012, 03:49:41 PM

I'm certainly not confused. I'm 100% certain rockets will not work in space.

What you show me on Earth will not work in the vacuum of space, which is what you people cannot comprehend.

How are you 100% certain you are correct in stating that rockets will not work in space?

For all the reasons I've stated.

It's rare for me to say I'm 100% correct because mostly I will say things are a possibility and I'm fairly certain or I have my suspicions, yet I'm 100% certain that no man made object has ever been into space.

So you arent 100% certain as you're just guessing?

No. I'm not guessing. I am 100% certain that rockets do not work in space, "if" space is the vacuum we are led to believe it is.

What have you been led to believe about the vacuum of space?

Quote from: Major Twang on November 30, 2012, 04:01:18 PM

Quote from: sceptimatic on November 30, 2012, 03:49:41 PM

I'm certainly not confused. I'm 100% certain rockets will not work in space.

What you show me on Earth will not work in the vacuum of space, which is what you people cannot comprehend.

If you think that Newtons 3rd law somehow fails to operate in low pressure environments, then you are certainly confused about something.

Newtons third law is simply twisted to fit space travel into the equation that's all.

Newton's third law is the conservation of momentum.  How is this 'twisted to fit' space travel ?  It works under all conditions.

That it's a near vacuum, not an absolute vacuum but close to it. Have you been told different?

Since you agree that space is not a perfect vacuum that means that you agree that the air pressure is very near, but not exactly equal to, zero.  The air pressure at sea level is about 14.7 psi.  The pressure inside a rocket's combustion chamber can 100-200 times the air pressure at sea level.  Do you honestly think that the the atmosphere at sea level will "devour" the exhaust gasses of a rocket any less vigorously than the near  vacuum of space?

Quote from: markjo on November 30, 2012, 05:01:14 PM

Quote from: sceptimatic on November 30, 2012, 04:41:21 PM

That it's a near vacuum, not an absolute vacuum but close to it. Have you been told different?

Since you agree that space is not a perfect vacuum that means that you agree that the air pressure is very near, but not exactly equal to, zero.  The air pressure at sea level is about 14.7 psi.  The pressure inside a rocket's combustion chamber can 100-200 times the air pressure at sea level.  Do you honestly think that the the atmosphere at sea level will "devour" the exhaust gasses of a rocket any less vigorously than the near  vacuum of space?

Devour?

No , no, no, you have it all wrong. I never mentioned Earth atmosphere devouring anything, I mentioned space swallowing up anything a rocket gave out rendering it useless.

I know what you said.  What I want to know is what does the 14,000+ psi in the rocket's combustion chamber care if it's being "swallowed" by 14.7 psi at sea level or near zero psi in space?

What makes a hot air balloon rise high into the sky?

The same principle that makes boats float; buoyancy.  The hot air in the balloon is less dense than the cool atmosphere around it.  However, this has nothing at all to do with rockets and vacuums.

What makes hot air balloons rise high into the sky.

Fully answer this question.

I already told you, buoyancy is the principle that makes hot air balloons float.  Hot air in the balloon is less dense than the relatively cool air of the atmosphere causing the to balloon rise.  Seriously, that's all there is to it.

http://en.wikipedia.org/wiki/Hot_air_balloon#Theory_of_operation

The heated air inside the envelope makes it buoyant since it has a lower density than the relatively cold air outside the envelope. As with all aircraft, hot air balloons cannot fly beyond the atmosphere. Unlike gas balloons, the envelope does not have to be sealed at the bottom since the air near the bottom of the envelope is at the same pressure as the surrounding air.

Just making sure you understood how it worked.

Now think of your rocket nozzle pumping that super hot flame under it, it heats up and expands against the dense cold atmosphere until the rocket is propelled upwards.

It simply works against the atmosphere but they can't tell us that it works this way as it kills off space travel, so they baffle your head with the mumbo jumbo of rockets actually magically kicking themselves up their own arses like a super fast Bruce Lee.

How about a water powered toy rocket. It is not heat propelling it.

Just making sure you understood how it worked.

Now think of your rocket nozzle pumping that super hot flame under it, it heats up and expands against the dense cold atmosphere until the rocket is propelled upwards.

It simply works against the atmosphere but they can't tell us that it works this way as it kills off space travel, so they baffle your head with the mumbo jumbo of rockets actually magically kicking themselves up their own arses like a super fast Bruce Lee.

Still now how rockets work.  Never has, never will.  All the arguments that show how you are incorrect you just ignore.  There is a reason you are the only one on this site arguing that rockets don't work in space.  I don't know why people are still trying.   

Just making sure you understood how it worked.

Now think of your rocket nozzle pumping that super hot flame under it, it heats up and expands against the dense cold atmosphere until the rocket is propelled upwards.

No.  Rockets do not work like hot air balloons.  Rockets are far too dense to be able to use buoyancy to fly.

It simply works against the atmosphere but they can't tell us that it works this way as it kills off space travel, so they baffle your head with the mumbo jumbo of rockets actually magically kicking themselves up their own arses like a super fast Bruce Lee.

No one has said anything about rockets "magically kicking themselves up their own arses", or any such nonsense, except for you. 

We already explained you how rockets work, first you said they pushed against air, now you say the are like hot air balloons? And you talk about common sense?
The speed of hot air moving upwards is nothing compared to the speed of the gasses expansions because of combustion, that is what moves the rocket.
No, the rocket does not push against itself, not in a nutshell. If that's how you understand it, you are not understanding it.

"They are still trying because I have put doubt in their minds and they are more questioning themselves than questioning my thoughts.

If they were 100% certain on what they were told to believe, they would have simply explained why it works their way and seen mine, then give up."

You really have no idea how everyone else here sees you, ignorance is bliss.

Sceptimatic, explain how your "theory" explains this video.  This video shows how rockets work. A force is applied to the medicine ball and in return an equal and opposite force is felt back.   
#ws" class="bbc_link" target="_blank" rel="noopener noreferrer">Medicine Ball Catch and Throw on Skateboard 

Quote from: sokarul on November 30, 2012, 06:18:51 PM

Sceptimatic, explain how your "theory" explains this video.  This video shows how rockets work. A force is applied to the medicine ball and in return an equal and opposite force is felt back.   
#ws" class="bbc_link" target="_blank" rel="noopener noreferrer">Medicine Ball Catch and Throw on Skateboard

On his throw, he is throwing the heavy ball which has mass and if you notice, it's not until he has released that ball that he move backwards, so it's mass and gravity, plus a small hint of atmosphere against his mass and energy.

No, he already had moving the moment he released the ball.

Now imagine just before he released that ball, I grabbed it from him with the same force as he was about to release it and flung it behind me......he would be rooted to the spot and that is what space would do to him.

So you're saying that space grabs the exhaust gasses from a rocket engine, right?  Tell me, just how does empty space grab anything?

Quote from: sceptimatic on November 30, 2012, 06:35:55 PM

Now imagine just before he released that ball, I grabbed it from him with the same force as he was about to release it and flung it behind me......he would be rooted to the spot and that is what space would do to him.

So you're saying that space grabs the exhaust gasses from a rocket engine, right?  Tell me, just how does empty space grab anything?

Don't you know? space is like a hungry lion.

Sceptimatic, you seem to be some kind of super troll. You are making claims that I don't think have been expressed here before. I can almost believe what you are saying, because of your enthusiasm.
 Do you have any proof, beside the 2 balloons?
 What makes you the rocket and space expert?
Are you a 14 year old kid with autism?
WTF?

Once it is released, it very quickly dissipates into the vastness of space, rendering the rocket, empty and rooted to the spot.

The rocket doesn't stay empty.  It uses the fuel to make constant pressure, which pushes on the inside surface in every direction except for the opening.

The movement started before he released the ball.

It depends which way you want to look at it.

On Earth, you suck out the air from a container and make a vacuum, now the air wants to get back into that vacuum and is all around that container just waiting for the breach so it can flow right back in and equalize right?

Now picture this scenario from the opposite way round.

In space you have the rocket that, (for instance in this case) is air filled against the expanse of space which contains no matter.

Instead of the air just being in that rocket, it now wants to get out and feed the vacuum and because there is no air pressure from outside acting on it, it starts to expand inside the rocket because it wants out and will keep expanding until the rocket casing splits or a nozzle is opened to release it.

Once it is released, it very quickly dissipates into the vastness of space, rendering the rocket, empty and rooted to the spot.


I do not expect you to accept or understand this because I think it's way beyond your acceptance. But there it is.

Doesn't matter, the metal rocket keeps the pressure. It won't expand. There is a higher pressure inside the rocket than outside, true. Rocket pressure is constantly increasing? no.

On Earth, you suck out the air from a container and make a vacuum, now the air wants to get back into that vacuum and is all around that container just waiting for the breach so it can flow right back in and equalize right?

Yes, air wants to go from a region of high pressure to low pressure.

In space you have the rocket that, (for instance in this case) is air filled against the expanse of space which contains no matter.

Instead of the air just being in that rocket, it now wants to get out and feed the vacuum and because there is no air pressure from outside acting on it, it starts to expand inside the rocket because it wants out and will keep expanding until the rocket casing splits or a nozzle is opened to release it.

Yes, combustion gasses in the rocket engine want to go from a region of high pressure to low pressure.

Once it is released, it very quickly dissipates into the vastness of space, rendering the rocket, empty and rooted to the spot.

I do not expect you to accept or understand this because I think it's way beyond your acceptance. But there it is.

I think the part that you can't accept is that the action/reaction happens within the combustion chamber before the gasses are released into the vacuum of space.