HAPPY HOAX ANNIVERSARY!!! (Rockets can't fly in a vacuum)

Quote from: Stash on November 12, 2019, 02:22:13 PM

Quote from: sceptimatic on November 12, 2019, 02:08:06 PM

Quote from: Stash on November 12, 2019, 12:27:31 PM

I did pay attention to your diagram. And your diagram still doesn't address the fact that the pressure inside the container is still pushing off all sides even when the valve is opened. So it's pushing. Even from the gauge side.

It's not pushing off all sides.

Once there is a breach the pushing is all expansion to the breach, in turn.
Think of it like a funnel.

Then the gauge at the top would immediately show zero pressure. It wouldn't drop. If it immediately when to zero, a balloon would immediately completely collapse when the end is opened. Please explain how there can still be pressure yet it has decided not to be pushing in all directions?

To do that you'll have to start looking at how a spring works.

Take a look at this spring being allowed to expand out of the front and also take a look at the untethered back end of the spring.
It is not compressing against the back of the magazine. It follows an expansion out of the magazine.

This is what gas does on expansion.

Think about it carefully.

The spring doesn't explain it. It is still applying pressure to the closed end. If you opened both ends at the same time, the spring would shoot out both ends.

What you can't explain is why with a gas it is still applying pressure on all sides when the container is breached at one end. And if it's applying pressure on all sides it is pushing. Hence the balloon does not immediately collapse when an end is opened.



Your spring does not cover this scenario. So what does? Think about it carefully.

Seriously.
Stringing along a bunch of sciency words doesnt make you sound smart.
And we know you like to change meanings.
You'll have to say it again in laymans terms.

Try not to concentrate on whether you think I'm trying to sound smart and concentrate on what my theory says.
You obviously are under no obligation to accept it in any way shape or form but you'll do yourself no favours by simply putting up your own barriers once you've asked a question or made a query.

Don't bother arguing this bit, I'm merely saying.

As we are too thick to get it, you should, again, present your theory to people who know better. I would be happy to follow that thread in whatever ”sciency” forum you choose as your platform.

The spring doesn't explain it. It is still applying pressure to the closed end. If you opened both ends at the same time, the spring would shoot out both ends.
[/quote] If you opened both ends on a gas container, the gas would expand both ways from each breach.
But this is not what we're debating.
All you seem to be doing here is dismissing the spring because it shows what I'm actually saying to be correct.

What you can't explain is why with a gas it is still applying pressure on all sides when the container is breached at one end. And if it's applying pressure on all sides it is pushing. Hence the balloon does not immediately collapse when an end is opened.



Your spring does not cover this scenario. So what does? Think about it carefully.

The spring does cover it, only this time it's about the gas or atmospheric air pressure.

Quote from: Stash on November 12, 2019, 04:08:00 PM

The spring doesn't explain it. It is still applying pressure to the closed end. If you opened both ends at the same time, the spring would shoot out both ends.

If you opened both ends on a gas container, the gas would expand both ways from each breach.
But this is not what we're debating.
All you seem to be doing here is dismissing the spring because it shows what I'm actually saying to be correct.

What you can't explain is why with a gas it is still applying pressure on all sides when the container is breached at one end. And if it's applying pressure on all sides it is pushing. Hence the balloon does not immediately collapse when an end is opened.



Your spring does not cover this scenario. So what does? Think about it carefully.

The spring does cover it, only this time it's about the gas or atmospheric air pressure.
[/quote]

No it's not showing what you are saying is correct because you're not addressing the issue with it. The issue is the gas it is still applying pressure on all sides when the container is breached at one end. You have admitted to this by the gauge at the top end dropping, not immediately going to zero.  And if it's applying pressure on all sides it is pushing. And as evidenced by the fact that the balloon does not immediately collapse when an end is opened. So it's pushing off of all sides, therefore it's pushing off the top. Which you had previously said it was not. But it is.

If it's pushing off the top of the container then it is pushing the container. If it's pushing the container, the container can move. If the container can move, it can move side to side, up, down, depending upon which way it's oriented. If the container can move by being pushed from the pressure on the inside it doesn't need to push off the atmosphere to move.

You meed to explain how there can be pressure pressing on all sides of the inside of the container and NOT getting a push as a result. What negates the push?

As we are too thick to get it, you should, again, present your theory to people who know better. I would be happy to follow that thread in whatever ”sciency” forum you choose as your platform.

It's not about being too thick to get it.
It's most likely that people find it hard to deviate from their general thoughts on how they've been told to perceive how and why rockets work and also work in a so called vacuum.

That's not down to being thick, it's down to trusting a model and what they believe is the correct science behind how it actually works.
Not a lot of people will entertain the thought of being duped.

The major problem with my explanations are from being too simple for those who are used to dealing with equations as their yardstick and  a refusal to actually entertain simple logic and simple analogies to that logic.
It likely embarrasses them in one way and also most likely skews their thoughts on the actual person or person's trying to force change their science world as they perceive it...so they basically put the shield up and use every avenue to deflect alternate theories/hypotheses or general musings.

The key for anyone who wants to learn is to look at the simplicity and attempt to marry it all up. Even if it's done for fun measure.
Nobody's forcing or even asking anyone to follow alternate models.

I refer to logic in the simplest form as in a bus near full of scientists and one small kid, being stuck in a tunnel due to the roof of the bus being too high for the tunnel.

The scientists get out their notepads and start to write down equations and take measurements of the bus and tunnel and working out the curve of the tunnel and the shape of the bus.
They manage to fill a notebook full of equations as to the best way to see this bus navigate this tunnel.

The kid jumps from the bus, looks up to the roof of the tunnel and at the bus, then looks down.
The kid then proceeds to let out air from the tyres. A few seconds from each tyre and the bus is on its way out of the tunnel.

Basically what I'm saying is, too many people look for the intricate routes when the simplicity of the shortcut is staring you in the face.

It's not pushing off all sides.

Repeatedly asserting the same falsehoods wont help you.
If you want to claim it isn't pushing off all sides then you need to explain how the pressure gauge works with nothing pushing on it (which is fundamentally how simple pressure gauges work) and you need to explain how a balloon stays inflated against the skin trying to collapse it with nothing pushing on it to keep it inflated, and how shrapnel from a bomb can be accelerated with nothing pushing on it, and how rockets in an atmosphere can accelerate with nothing pushing on it.

Simple observations show you are completely wrong and that even when there is an opening gas still pushes outwards in all directions.

Pay attention to what's being said. You're mixing it up.

I am paying attention and I'm not mixing anything up.

Showing that you are contradicting yourself by bringing up to of your "explanations" which directly contradict each other is not mixing things up. It is showing the massive problems in your model.

I've wiped the rest of your stuff because it's clear to see what your game is.

Yes, it is clear to see that my game is to show the truth and expose the problems with your model. But you can't have that. You don't want to admit your model is wrong, so you will just ignore everything that does.

It is clear that I am quite happy to expose multiple problems and show how your claims to try and solve one problem directly contradict another claim of yours.
You can't handle that so you will just ignore what I say to pretend you haven't been refuted yet again.

From this point on deal with one thing at a time.

Already tried that with you. You started ignoring me. So no, I will continue to expose everything wrong with your claims.

If you want to just deal with one thing at a time, then tell me what the gas is pushing off which allows it to move in a vaccuum.
If you want to say it is itself, you need to explain how the rocket can't just push off itself.
If you want to say it is the other gas, then you need to explain how the rocket can't push off the gas.
If you want to say it is the rocket, then you need to explain why it isn't pushed away by the gas.
If you don't have an answer then you need to admit that rockets work in a vacuum.

To do that you'll have to start looking at how a spring works.

Yes, where we notice that if you do not keep a force applied to the spring, it will move back to its "natural" length.
That means that if the gas isn't pushing against the pressure gauge, it will read 0.

If you need an example of how it works in reality, take a look at this slinky video (there are plenty of others out there):


Notice that when it is released, the slinky doesn't just decide to all start moving down like you want to pretend. Instead the slinky is under tension. The bottom of it will remain held up by that tension until the tension is relaxed.

Think carefully, because what you are saying makes no sense.

concentrate on what my theory says.

You have no theory to concentrate on. You have a bunch of contradictory claims, plenty of which contradict reality.

It's most likely that people find it hard to deviate from their general thoughts on how they've been told

No, it's most likely that people find it hard to deviate from reality and move towards self-contrdictory nonsense.

It isn't down to being thick.
It is down to your model being wrong and you being unable to explain anything without contradicting reality or yourself.

Basically what I'm saying is, too many people look for the intricate routes when the simplicity of the shortcut is staring you in the face.

Yes, you do like looking for the intricate routes when the simplicity of reality is staring you in the face.

The simple reality of rockets working in space:
Gas pushes rocket one way, rocket push gas the other way.
No need for any complicated garbage.
Rockets work in space.

No it's not showing what you are saying is correct because you're not addressing the issue with it. The issue is the gas it is still applying pressure on all sides when the container is breached at one end. You have admitted to this by the gauge at the top end dropping, not immediately going to zero.

You not understanding this means we need to concentrate on this instead of you getting way beyond yourself.
You argue there's a push at each end when there's is a breach at one end.
You placed the gauge scenario at the closed end to try and back up your theory.
I shot it down by telling you the gauge pressure lowers.
Now you've changed up to a balloon and are arguing that against this container.
They're two entirely different things.

So let's deal with one thing at a time.
Let's deal with the gauge and container and why the gauge pointer shows a lesser pressure as the opposite end valve is opened.

 I explained what happens, now tell me why you think I'm wrong.

No need for any complicated garbage.
Rockets work in space.

So why are you arguing with me?

Quote from: Macarios on November 12, 2019, 03:25:02 AM

Quote from: sceptimatic on November 10, 2019, 09:56:51 PM

Quote from: Macarios on November 10, 2019, 04:14:36 PM

Expansion begins only AFTER one end is open.

Which I've already explained.

You just tried to avoid the fact that the said expansion goes in all direction, including the push on the sealed end.

Nope. I've already explained all directions when contained and one direction when breached container allows expansion.

You are trying to hide the fact that the expansion continues in all direction all the time.

Quote from: Stash on November 12, 2019, 11:31:30 PM

No it's not showing what you are saying is correct because you're not addressing the issue with it. The issue is the gas it is still applying pressure on all sides when the container is breached at one end. You have admitted to this by the gauge at the top end dropping, not immediately going to zero.

You not understanding this means we need to concentrate on this instead of you getting way beyond yourself.
You argue there's a push at each end when there's is a breach at one end.
You placed the gauge scenario at the closed end to try and back up your theory.
I shot it down by telling you the gauge pressure lowers.
Now you've changed up to a balloon and are arguing that against this container.
They're two entirely different things.

So let's deal with one thing at a time.
Let's deal with the gauge and container and why the gauge pointer shows a lesser pressure as the opposite end valve is opened.

 I explained what happens, now tell me why you think I'm wrong.

Fair enough, I explained what I was asking for, but I probably muddied it with the balloon. So back to the container with the valve on one end, the gauge on the other.

The gauge at the top registers the internal pressure, the valve at the bottom is closed. Pressure inside is pushing in all directions within the container. The valve is opened. The pressure gauge on top starts to drop as gas is exiting the valve. If the gauge is still registering a drop and doesn't instantaneously go right to zero:

Pressure is still pushing off the top of the container where the gauge is which means the pressure is pushing against the container. If it's pushing against the container, the container can move. If the container can move, it can move side to side, up, down, depending upon which way it's oriented. If the container can move by being pushed from the pressure on the inside it doesn't need to push off the atmosphere to move.

You need to explain how there can be pressure pressing on all sides of the inside of the container and NOT getting a push as a result. What negates the push? Where does that pressure go?

You not understanding

People realising you are wrong doesn't mean they don't understand.

I shot it down by telling you the gauge pressure lowers.

No, you shot nothing down. You just avoided it.
If the gas magically stopped applying pressure, the pressure would drop to 0, not some lower value, 0, as there would be no pressure applied to the gauge.

In order to have the gauge read a value, you need to accept pressure is still being applied to it, meaning you need to reject your claim that pressure just magically pushes to the opening.

Now you've changed up to a balloon and are arguing that against this container.
They're two entirely different things.

While they are not the same, they show the same problem.
If what you are saying is true, and that as soon as there is an opening the pressure will magically just push towards it, then the balloon cannot remain inflated and would need to shrink basically instantly, regardless of how slowly the air is released.
If what you are saying is true, and that as soon as there is an opening the pressure will magically just push towards it, then the pressure gauge cannot remain showing a pressure and instead must show 0.
In order for the balloon to remain inflated, pressure needs to push outwards on it, not just towards the opening.
In order the the pressure gauge to read a pressure, pressure needs to push outwards on it, not just towards the opening.

I explained what happens, now tell me why you think I'm wrong.

We have told you why you are wrong, repeatedly. You just repeatedly ignore it.

Again, the only way for the gauge to read a pressure is if the pressure was pushing against it. You say the pressure only pushes to the opening.
That is why you are wrong.

So why are you arguing with me?

Because unlike you I care about the truth and will object when I see people spouting nonsense.

Now have you figured out an answer to any of the multitude of problems you have been presented with; an answer which doesn't contradict yourself?

Preferably one which addresses the topic of this thread:
tell me what the gas is pushing off which allows it to move in a vaccuum.
If you want to say it is itself, you need to explain how the rocket can't just push off itself.
If you want to say it is the other gas, then you need to explain how the rocket can't push off the gas.
If you want to say it is the rocket, then you need to explain why it isn't pushed away by the gas.
If you don't have an answer then you need to admit that rockets work in a vacuum.

You are trying to hide the fact that the expansion continues in all direction all the time.

Do you actually know what you're saying?

Hide it as in how?

Fair enough, I explained what I was asking for, but I probably muddied it with the balloon. So back to the container with the valve on one end, the gauge on the other.

The gauge at the top registers the internal pressure, the valve at the bottom is closed. Pressure inside is pushing in all directions within the container.

I'm happy with this explanation so we can put this one to bed.

The valve is opened. The pressure gauge on top starts to drop as gas is exiting the valve. If the gauge is still registering a drop and doesn't instantaneously go right to zero:

And nor should it.
It's a gradual expansion of molecules starting at the breach/opening and every stack of molecules directly behind those going out that breach.....meaning you have a chain reaction.

The emptying of the container is solely down to the external resistance of the molecules against that opening...or to make it simpler....atmospheric pressure.

Pressure is still pushing off the top of the container where the gauge is which means the pressure is pushing against the container.

Not when it's breached.

If it's pushing against the container, the container can move. If the container can move, it can move side to side, up, down, depending upon which way it's oriented. If the container can move by being pushed from the pressure on the inside it doesn't need to push off the atmosphere to move.

It's not pushed from the pressure on the inside.
It's pushed by the release of that pressure against the external resistant atmosphere, creating a gas on gas fight.

You need to explain how there can be pressure pressing on all sides of the inside of the container and NOT getting a push as a result. What negates the push? Where does that pressure go?

The pressure is a chain reaction against a resistance of external pressure.
There was a reason I mentioned a spring as an analogy and it's a great analogy if taken notice of.

Quote from: sceptimatic on November 13, 2019, 01:59:15 AM

You not understanding

People realising you are wrong doesn't mean they don't understand.

I know they don't understand (including you) by the questions being asked.

Quote from: JackBlack on November 13, 2019, 02:41:03 AM

Quote from: sceptimatic on November 13, 2019, 01:59:15 AM

You not understanding

People realising you are wrong doesn't mean they don't understand.

I know they don't understand (including you) by the questions being asked.

Either because its wrong, you purpisefully misuse common definitions for words and dont priperly redefine what youre saying, or you overly complicate it with bad analogies thst contradict themselves and reality.

Or possibly all the above.
If it were so simple you could draw a picture, all industrialized world would be using your system, easily describe and communicate.

Quote from: Themightykabool on November 12, 2019, 03:28:39 PM

Seriously.
Stringing along a bunch of sciency words doesnt make you sound smart.
And we know you like to change meanings.
You'll have to say it again in laymans terms.

Try not to concentrate on whether you think I'm trying to sound smart and concentrate on what my theory says.
You obviously are under no obligation to accept it in any way shape or form but you'll do yourself no favours by simply putting up your own barriers once you've asked a question or made a query.

Don't bother arguing this bit, I'm merely saying.

Funny thing to cut out your gobbly gook.

Lets put it back in:

Scepti quote
"Too much dissipation of pressure by the pressure not being dense enough to cut through the atmospheric resistance in the stack directly below the expansion of rocket gas."

Breakdown:

Rocket gas in this case of a water rocket is just regular air, squeszed and crushed so more sponges are in the container.


Disspation means expansion of sponges?

Pressure is compression level of the sponges.

Density (denP) means the sponges have displaced a certain amount of air giving it "weight".
What does the exiting sponge air denP weight have to do with the denP wieght of air below it in the external sponge stack?
Why does it have to "cut through" when your spring on spring or two guys standing on each other in a rocket analogies describe liftoff as sponges on sponges expanding up.

Quote from: sceptimatic on November 13, 2019, 03:35:05 AM

Quote from: JackBlack on November 13, 2019, 02:41:03 AM

Quote from: sceptimatic on November 13, 2019, 01:59:15 AM

You not understanding

People realising you are wrong doesn't mean they don't understand.

I know they don't understand (including you) by the questions being asked.

Either because its wrong, you purpisefully misuse common definitions for words and dont priperly redefine what youre saying, or you overly complicate it with bad analogies thst contradict themselves and reality.

Or possibly all the above.
If it were so simple you could draw a picture, all industrialized world would be using your system, easily describe and communicate.

There are no contradictions.
You people make out there is because you do not understand what I'm pointing out. You only partly get it then destroy your whole effort.
That's a problem you and others need to address...not me.

Quote from: sceptimatic on November 12, 2019, 10:12:58 PM

Quote from: Themightykabool on November 12, 2019, 03:28:39 PM

Seriously.
Stringing along a bunch of sciency words doesnt make you sound smart.
And we know you like to change meanings.
You'll have to say it again in laymans terms.

Try not to concentrate on whether you think I'm trying to sound smart and concentrate on what my theory says.
You obviously are under no obligation to accept it in any way shape or form but you'll do yourself no favours by simply putting up your own barriers once you've asked a question or made a query.

Don't bother arguing this bit, I'm merely saying.

Funny thing to cut out your gobbly gook.

Lets put it back in:

Scepti quote
"Too much dissipation of pressure by the pressure not being dense enough to cut through the atmospheric resistance in the stack directly below the expansion of rocket gas."

Breakdown:

Rocket gas in this case of a water rocket is just regular air, squeszed and crushed so more sponges are in the container.

Correct.

Disspation means expansion of sponges?

In terms of the sponges it means equalisation. Basically becoming irrelevant to work done.
In a nutshell it's exhaust in the proper sense, not in the fiery sense what is told about a rocket thrust.
Let's not worry about this bit as of yet as it will skew what could potentially be a major grasp for you.

Pressure is compression level of the sponges.

Correct.

Density (denP) means the sponges have displaced a certain amount of air giving it "weight".

Correct.

What does the exiting sponge air denP weight have to do with the denP wieght of air below it in the external sponge stack?

Nothing.
The air below it is one part of a stack that any dense mass would be up against...assuming a hanging object where the bottom sits atop of one part of the stack which is doing nothing more than being the calm surface, if you like.
It only comes into play when the object is pushed into it, which is when resistance comes into play, whether it's a rocket burn or a water bottle rocket thrust or merely a object dropped from a point of potential energy hold....for instance a hanging object on a string that is cut.

It's important to know all of this so what I say becomes relevant and your mind doesn't kick into thinking I'm contradicting myself.

Why does it have to "cut through" when your spring on spring or two guys standing on each other in a rocket analogies describe liftoff as sponges on sponges expanding up.

To give you a simple analogy (and take it as that and do not use it as an argument) we'll imagine a bus that is sealed off and inside it are people all crammed in to such an extent they have to fight to stop themselves being crushed.
Imagine if they could survive being crushed smaller.
Ok so now you can imagine that...if the bus was sealed at each end, the crush would be even from back to front. Even pressure hitting both sealed off exits and also everyone squashed against the side walls and ceiling of that bus, plus floor.

Ok we both know this as being a sealed container of pressure, right, so let's see what happens.

Outside of that bus are a crowd of people who are body to body and slightly compressing into each other all around That bus and also stood on top of each other and also on top of the bus with people stood on top of them...and so on.
Under the bus there would be a few laid under it but not being squashed more than the rest because the bus wheels hold back the dense mass on it by using a solid ground.

Ok, so what we know is, the people inside the bus are itching to decompress. They're trying to break open the bus at its weakest point (assume windowless...let's not add in issues).
Suddenly the back door is breached and the compressed people in that bus start to decompress against the looser compression of the external crowd and manage to push some out of the way which compresses them into the people behind them.
However, inside the bus, the people behind the first out can also decompress as they push and are pushed into the first.
The one behind does the same.
By this time it will be noted that the bus is moving in the opposite direction and all the work done at the first decompression is filled by the falling people from above who fill the void that the first decompressed person created by compressing the crowd back...which as you know were less compressed at first.

Now this keeps happening because there's so many people crammed into the bus and it becomes each person expanding out and expanded into the back of.
As a little time goes on, the expansion inside the bus will become less and less as more people are pushed out.

Now here's the key.

The people at the other end of the bus have had to wait their turn to fully expand because all the way down that bus  became a slight expansion of each person from large (front) to extremely small (back).

Everybody expands at the front and is followed by those behind in a natural decompression.

By the time most are out, there's still some people still left inside the bus, all of who are simply equalised to the people outside of it.
There becomes no more movement. of the bus.


Read this carefully, seriously.
Absorb what's been said because you're getting closer to understanding, whether you end up agreeing or not.

To give you a simple analogy (and take it as that and do not use it as an argument) we'll imagine a bus that is sealed off and inside it are people all crammed in to such an extent they have to fight to stop themselves being crushed.
Imagine if they could survive being crushed smaller.
Ok so now you can imagine that...if the bus was sealed at each end, the crush would be even from back to front. Even pressure hitting both sealed off exits and also everyone squashed against the side walls and ceiling of that bus, plus floor.

Ok we both know this as being a sealed container of pressure, right, so let's see what happens.

Outside of that bus are a crowd of people who are body to body and slightly compressing into each other all around That bus and also stood on top of each other and also on top of the bus with people stood on top of them...and so on.
Under the bus there would be a few laid under it but not being squashed more than the rest because the bus wheels hold back the dense mass on it by using a solid ground.

Ok, so what we know is, the people inside the bus are itching to decompress. They're trying to break open the bus at its weakest point (assume windowless...let's not add in issues).
Suddenly the back door is breached and the compressed people in that bus start to decompress against the looser compression of the external crowd and manage to push some out of the way which compresses them into the people behind them.
However, inside the bus, the people behind the first out can also decompress as they push and are pushed into the first.
The one behind does the same.
By this time it will be noted that the bus is moving in the opposite direction and all the work done at the first decompression is filled by the falling people from above who fill the void that the first decompressed person created by compressing the crowd back...which as you know were less compressed at first.

Now this keeps happening because there's so many people crammed into the bus and it becomes each person expanding out and expanded into the back of.
As a little time goes on, the expansion inside the bus will become less and less as more people are pushed out.

Now here's the key.

The people at the other end of the bus have had to wait their turn to fully expand because all the way down that bus  became a slight expansion of each person from large (front) to extremely small (back).

Everybody expands at the front and is followed by those behind in a natural decompression.

By the time most are out, there's still some people still left inside the bus, all of who are simply equalised to the people outside of it.
There becomes no more movement. of the bus.


Read this carefully, seriously.
Absorb what's been said because you're getting closer to understanding, whether you end up agreeing or not.

What dribble!
Suqashy people are on a totally different scale to air (and gas, or combustion) particles...

Duh!...

Quote

To give you a simple analogy (and take it as that and do not use it as an argument) we'll imagine a bus that is sealed off and inside it are people all crammed in to such an extent they have to fight to stop themselves being crushed.
Imagine if they could survive being crushed smaller.
Ok so now you can imagine that...if the bus was sealed at each end, the crush would be even from back to front. Even pressure hitting both sealed off exits and also everyone squashed against the side walls and ceiling of that bus, plus floor.

Ok we both know this as being a sealed container of pressure, right, so let's see what happens.

Outside of that bus are a crowd of people who are body to body and slightly compressing into each other all around That bus and also stood on top of each other and also on top of the bus with people stood on top of them...and so on.
Under the bus there would be a few laid under it but not being squashed more than the rest because the bus wheels hold back the dense mass on it by using a solid ground.

Ok, so what we know is, the people inside the bus are itching to decompress. They're trying to break open the bus at its weakest point (assume windowless...let's not add in issues).
Suddenly the back door is breached and the compressed people in that bus start to decompress against the looser compression of the external crowd and manage to push some out of the way which compresses them into the people behind them.
However, inside the bus, the people behind the first out can also decompress as they push and are pushed into the first.
The one behind does the same.
By this time it will be noted that the bus is moving in the opposite direction and all the work done at the first decompression is filled by the falling people from above who fill the void that the first decompressed person created by compressing the crowd back...which as you know were less compressed at first.

Now this keeps happening because there's so many people crammed into the bus and it becomes each person expanding out and expanded into the back of.
As a little time goes on, the expansion inside the bus will become less and less as more people are pushed out.

Now here's the key.

The people at the other end of the bus have had to wait their turn to fully expand because all the way down that bus  became a slight expansion of each person from large (front) to extremely small (back).

Everybody expands at the front and is followed by those behind in a natural decompression.

By the time most are out, there's still some people still left inside the bus, all of who are simply equalised to the people outside of it.
There becomes no more movement. of the bus.


Read this carefully, seriously.
Absorb what's been said because you're getting closer to understanding, whether you end up agreeing or not.

What dribble!
Suqashy people are on a totally different scale to air (and gas, or combustion) particles...

Duh!...

There's always generally one.
Maybe a few more might follow that predictable jump in.

 

Right...so when does water come into play for the water rocket?

Right...so when does water come into play for the water rocket?

When it's pushed out of the rocket opening under massive pressure against the atmospheric stack directly under it.

 

Quote from: Themightykabool on November 13, 2019, 09:28:54 AM

Right...so when does water come into play for the water rocket?

When it's pushed out of the rocket opening under massive pressure against the atmospheric stack directly under it.

So why cant the air do that?
If all ejected material sits on top of the stack of spongy air, why is it that the water rocket works best when using water, and not more air.

Your most detailed response so far is the "dissipation".
Which then contradicts lift off in general because the rocket is supposedly sitting on a stack of sponges.
You seem to keep dodging this.

Quote from: Stash

The valve is opened. The pressure gauge on top starts to drop as gas is exiting the valve. If the gauge is still registering a drop and doesn't instantaneously go right to zero:

And nor should it.

In reality, yes, as the pressure is still pushing on the gauge, because it doesn't just magically go straight out towards the opening and stopping every other direction.
For your model, it should go to 0, because you claim that the pressure is no longer pushing against it and thus the pressure it is measuring is 0.

You seriously need to make up your mind.
Is the pressure still pushing upwards on the gauge allowing it to read a pressure, or is it only pushing towards the opening, meaning no pressure on the gauge, meaning the gauge will read 0?

It's pushed by the release of that pressure against the external resistant atmosphere, creating a gas on gas fight.

HOW?
The only thing it is in contact with to push it to create a reading is the gas on the inside.
If that gas is not pushing against it (like you claim) then it will read 0.
Try explaining just what else is pushing on it and how.

I know they don't understand (including you) by the questions being asked.

You mean you know they show you are wrong, so you feel a need to insult them and dismiss you.

By the questions they are asking it is quite clear that they do understand your claims and realise your claims are wrong.

There are no contradictions.

There are so many it isn't funny.
You ignoring them doesn't magically make them go away.
Your inability or unwillingness to answer very simple questions which expose these contradictions shows you know there are contradictions and you have no rational solution to remove the contradiction which doesn't show your model is wrong.

If there weren't contradictions you could easily answer these questions you repeatedly avoid.

To give you a simple analogy (and take it as that and do not use it as an argument)

If you don't want an analogy you provide to be used against your model do not provide it.
If your analogy has a massive error in it for the application of it to gas or the like, it will be pointed out.

imagine a bus that is sealed off and inside it are people all crammed in to such an extent they have to fight to stop themselves being crushed.

This would be a liquid, not a gas.

Try it without the air outside.
You have the people pushing outwards in every direction trying to get more room.
Also note that these people are not intelligent in any way (unless you wish to claim gas is sentient), and they have no desire to leave the bus. All they want is to get more space.
So they are pushing outwards in every direction, including against the bus.
But the bus doesn't move because that pressure is equal.

Now the door opens at the front and a few people get pushed out by the people behind them trying to get more room.
The people at the back and still pushing outwards in every direction, because what has happened at the front hasn't gotten back to them in the form of less compressed people in front of them.
That means the gas is still pushing outwards in all directions.
However at the front, the door is open and the bus no longer has people pushing against the door.
Instead those that would normally try to push against it fall out of the bus/get pushed out by the people behind them.

This means the force on the bus is no longer equal and thus the bus moves.

This forcing continues through the rocket, with more people slowly getting pushed out, developing a pressure gradient across the rocket, such that the pressure is much larger at the back than the front.
This keeps pushing the bus.
It is only once the pressure has equalised (i.e. dropped to basically 0) that the bus stops having a force exerted.

But instead of allowing that, we will make it more like a conventional chemical fuel rocket.
We don't just have a static number of people now.
Instead we are dumping more people into the bus, at the back of the bus.
This makes the pressure there higher and pushes people in the middle towards the front of the bus.
We can even throw in a nozzle, but that is getting more complicated.

Notice how when done properly, this ridiculous analogy still shows that rockets work in a vacuum.

To do what you claim, you have these dumb people that are pushing outwards in every direction to try and get more space suddenly stop and just push towards the door, even though they have no idea where that door is, nor any desire to actually go through the door.

Read this carefully, seriously.
Absorb what's been said because you're getting no closer to understanding by just ignoring everything that shows you are wrong.

When it's pushed out of the rocket opening under massive pressure against the atmospheric stack directly under it.

The air would be able to do that as well.
So why the water?
Just what is the water doing that the air couldn't?

And have you thought of a solution to your massive problems yet?
For the pressure gauge and the balloon, how does the gauge still read a pressure and the balloon stay stretched out when it needs the gas inside to push against it in order to do so, which you said does not happen?

For the cold gas thruster, What the gas is pushing off which allows it to move in a vacuum?
If you want to say it is itself, you need to explain how the rocket can't just push off itself.
If you want to say it is the other gas, then you need to explain how the rocket can't push off the gas.
If you want to say it is the rocket, then you need to explain why it isn't pushed away by the gas.
If you don't have an answer then you need to admit that rockets work in a vacuum.

Quote from: Stash

The valve is opened. The pressure gauge on top starts to drop as gas is exiting the valve. If the gauge is still registering a drop and doesn't instantaneously go right to zero:

And nor should it.

Contradiction:

Quote from: Stash

Pressure is still pushing off the top of the container where the gauge is which means the pressure is pushing against the container.

Not when it's breached.

If the gauge is still registering pressure after the breach then pressure must still be exerting on the gauge for it to have a reading. So how can you say on the the one hand, the gauge is still reading pressure after the breach yet on the other hand no pressure is being applied to the gauge after the breach?

Sceptis sponges have to be sentient in order to know which way is down.

Quote from: sceptimatic on November 13, 2019, 09:48:42 AM

Quote from: Themightykabool on November 13, 2019, 09:28:54 AM

Right...so when does water come into play for the water rocket?

When it's pushed out of the rocket opening under massive pressure against the atmospheric stack directly under it.

So why cant the air do that?
If all ejected material sits on top of the stack of spongy air, why is it that the water rocket works best when using water, and not more air.

Air can do it but the air alone is dissipated very quickly against the stack which gives very little gas on gas push to lift the rocket.

Your most detailed response so far is the "dissipation".
Which then contradicts lift off in general because the rocket is supposedly sitting on a stack of sponges.
You seem to keep dodging this.

I'm not dodging anything. I've explained the water but you're dodging that issue.

Water is much more dense and is not easily dissipated into the atmospheric stack. It manages to be pushed harder into it to compress that stack much more than just air alone would.

I have a feeling you're going to slip right back to square one soon enough.

Quote from: sceptimatic on November 13, 2019, 03:33:42 AM

Quote from: Stash

The valve is opened. The pressure gauge on top starts to drop as gas is exiting the valve. If the gauge is still registering a drop and doesn't instantaneously go right to zero:

And nor should it.

In reality, yes, as the pressure is still pushing on the gauge, because it doesn't just magically go straight out towards the opening and stopping every other direction.
For your model, it should go to 0, because you claim that the pressure is no longer pushing against it and thus the pressure it is measuring is 0.

You seriously need to make up your mind.
Is the pressure still pushing upwards on the gauge allowing it to read a pressure, or is it only pushing towards the opening, meaning no pressure on the gauge, meaning the gauge will read 0?

I don't need to make up my mind. It's made up and is consistent.
You simply refuse to grasp it.

Once the valve is opened the gauge now starts to reads a continuous lowering of pressure on the gauge. It means the gauge is not under pressure, it's losing that pressure because everything is expanding out.

How?
Massive expansion at the valve opening and gradually less expansion of molecules all the way to close to the gauge side, all pushing one way, which is why the gauge pointer continues to read lower and lower pressure.

Quote from: JackBlack on November 13, 2019, 12:53:09 PM

Quote from: sceptimatic on November 13, 2019, 03:33:42 AM

Quote from: Stash

The valve is opened. The pressure gauge on top starts to drop as gas is exiting the valve. If the gauge is still registering a drop and doesn't instantaneously go right to zero:

And nor should it.

In reality, yes, as the pressure is still pushing on the gauge, because it doesn't just magically go straight out towards the opening and stopping every other direction.
For your model, it should go to 0, because you claim that the pressure is no longer pushing against it and thus the pressure it is measuring is 0.

You seriously need to make up your mind.
Is the pressure still pushing upwards on the gauge allowing it to read a pressure, or is it only pushing towards the opening, meaning no pressure on the gauge, meaning the gauge will read 0?

I don't need to make up my mind. It's made up and is consistent.
You simply refuse to grasp it.

Once the valve is opened the gauge now starts to reads a continuous lowering of pressure on the gauge. It means the gauge is not under pressure, it's losing that pressure because everything is expanding out.

How?
Massive expansion at the valve opening and gradually less expansion of molecules all the way to close to the gauge side, all pushing one way, which is why the gauge pointer continues to read lower and lower pressure.

That literally makes no logical sense. The gauge wouldn't read any pressure if it wasn't under some pressure. Hence the name, "pressure gauge".

If the gauge is not under pressure, it would immediately read 0.