Rockets do not work in the vacuum of space. You will believe anything "expert" scientists say.

a reply to: captainpudding

Prove that it’s not pushing off the atmosphere

a reply to: NicSign

Prove that it is.

You not getting how this works yet? Your pointless game playing isn't helping you prove a thing other than how shallow your depth of knowledge is.

You've had all the evidence you had the cheek to demand, supply some of your own.

a reply to: NicSign

Prove that it is.

You not getting how this works yet? Your pointless game playing isn't helping you prove a thing other than how shallow your depth of knowledge is.

You've had all the evidence you had the cheek to demand, supply some of your own.

a reply to: OneBigMonkeyToo

It’s already been shown that it pushes off external resistance

www.youtube.com...

a reply to: NicSign

Wow. A rebuttal with a link to a propaganda video with no constructed argument from a conspiracist? Say it’s not so.

Again.

You are trying to compare apples to oranges. Or kinetic energy provided by a chemical reaction in a motor vs sail power would be a better example.

You can not ignore the actual reaction of the fuel and oxidizer. You act like there is no reaction going on that consumes large masses of reactants that generate heat and expanding exhaust gasses with large amounts of resultant kinetic energy colliding with the rocket motor walls.

What you are doing is acting like there is no reaction in a rocket motor, and ignoring the design of a rocket motor is built to maintain pressure and a specific expansion of the exhaust gasses.

For the thousand time. Reactants are injected into a combustion chamber. It’s essential a controlled explosion. If it wasn’t for the combustion chamber, the expanding gasses would expand in a sphere. The gasses expand because the reaction gave them kinetic energy. It doesn’t mater if the reaction took place at 14.7 psig, or in a vacuum. When confined to a combustion chamber, the throat of the nozzle, and the provided surface area of the nozzle, the molecules of the exhaust gasses are given kinetic energy by the reaction in the combustion chamber. The actual collisions with the rocket motor walls by the exhaust gas molecules moving with kinetic energy are what create the equal and opposite reaction that results in thrust. The exhaust gasses are expanding and still colliding with the nozzle walls when they exit the motor by design. The gas moving into the “vacuum” of space is still moving with great velocity and still has kinetic energy.

Again, the throat of the rocket engine is used to maintain pressure in the combustion chamber in connection with specific types of reactants and reaction rates. The nozzle of the rocket motor is used to achieve a desired expansion of the exit gasses.

a reply to: NicSign

No it hasn't. You've proved nothing other than a desire to get the entire internet to watch your videos.



I've held my hand right under that jet, makes no difference. The shower head movement is caused by action-reaction, not pushing against air.

a reply to: OneBigMonkeyToo

It’s a shower head, use a jet nozzle.

a reply to: neutronflux

So if a rocket made of indestructible material went to the sun where atmospheric pressure is 5000psi. The rocket only produces 5000psi in its chamber, will there be thrust? Why or why not?

originally posted by: NicSign
a reply to: neutronflux

So if a rocket made of indestructible material went to the sun where atmospheric pressure is 5000psi. The rocket only produces 5000psi in its chamber, will there be thrust? Why or why not?

Depends on how dependent the actual reaction is on pressure. If the reaction still takes place, the reaction could basically act like a positive displacement pump giving kinetic energy to gasses until pressure builds to the point it overcomes the outside pressure. So if the reaction is able to take place, and there is enough fuel, the reaction may very well create enough pressure in the combustion chamber to overcome the outside pressure.

But think about it this way. The pressure of the combustion chamber is open to the outside pressure through the nozzle opening if there was no reaction. The chamber pressure is going to be the same as the outside pressure by default with no reaction taking place. If the reaction of the rocket fuel can take place and starts, it’s going to create gasses with kinetic energy that will pressure up the chamber greater than the surrounding static pressure.

But the sun’s gravity is going to negate any thrust.

Then you get into temperature vs pressure if the exhaust gas will compress to a liquid. Or the pressure may actually prevent the rocket fuel from reacting.

Then you get into this situation. A small fire cracker that can create enough kinetic energy to destroy a small cardboard box and throw pieces of cardboard about may not do anything to a foot of 1” threaded pipe rated for 1500 psi capped off with pipe caps rated for 1500 psi. If the expanding gasses from the small exploding fire cracker cannot create a breach in the pipe, the kinetic energy of the gas inside the pipe is the same on all walls of the pipe, so no thrust is created.

So yes. You get into the reaction may not have enough kinetic energy to produce thrust for the GRAVITY of the sun. The inside of the rocket motor by the opening through the nozzle will have a starting pressure of the outside pressure, any sustained reaction of rocket fuel will have exhaust gasses with kinetic energy that will pressure up the inside of the rocket motor greater than ambient ( outside ) pressure.

Still has nothing to do with pressure gradient force. Has everything to do with the available kinetic energy of the gasses from the rocket fuel reaction.

originally posted by: NicSign
a reply to: OneBigMonkeyToo

It’s a shower head, use a jet nozzle.

I'm not installing a new bathroom just to keep idiots happy. The physics are the same. If you don't agree, find a jet nozzle and repeat the experiment yourself.

a reply to: NicSign

Then you didn’t clarify temperature. If the temperature of the sun is greater than the max temperature the reaction of the fuel can achieve, the surrounding plasma / gasses is always going to have more energy than what the rocket is producing.

a reply to: neutronflux

Hence no pressure gradient force. It’s not the rocket pushing the exhaust out

originally posted by: NicSign
a reply to: neutronflux

Hence no pressure gradient force. It’s not the rocket pushing the exhaust out

What? It's the reaction of oxidizer and fuel releasing energy that gives kinetic energy to the expanding gasses that results in collisions with the rocket motor wallls that results in thrust through Newton’s third law.

a reply to: NicSign

I am getting closer to using a clear PVC pipe as a “vacuum” chamber. Until then.....

Estes 1/4A3-3T rocket motor against 5 HP Shopvac.

Picture below for scale.



1/4A3-3T size vs the A8-3 rocket motor used in the first Shopvac experiment.

For this experiment, I used an Estes Mosquito rocket and a 1/4A3-3T rocket motor. The 1/4A3-3T is what I think is Estes smallest engine in current production.

The 1/4A3-3T specs:
Total impulse: .625 N-sec
Max Thrust: a whopping 4.9 Newtons
Thrust Duration: .25 Sec

The 1/4A3-3T with its 4.9 Newtons out workers a 5 HP Shopvac to launch from a “vacuum” and lack of “back pressure”

The test was done twice. One flight with a blue tape band to hold the tube to ride the wire. The second flight was with a black tape band.

Picture of entire thrust of the blue band rocket flight consumed by the Shopvac

Link to the blue band flight video

1/4A3-3T Rocket Motor VS 5 Hp Shopvac - blue - right - short
www.youtube.com...

Picture of the entire thrust of the black band rocket flight consumed by the Shopvac

Links to the black rocket flights

1/4A3-3T Rocket Motor Vs 5 Hp Shopvac - black - left side
www.youtube.com...

1/4A3-3T Rocket Motor VS 5 Hp Shopvac -Black- right side
www.youtube.com...

The 1/4A3-3T max thrust of 4.9 Newtons without hesitation takes off from the “vacuum” and “no back pressure” created by the 5 Hp Shopvac in its suction hose.

Links to the A8-3 original flight VS 5HP Shopvac

A8-3 Rocket Motor Vs 5HP ShopVac two
www.youtube.com...

A8-3 Rocket Motor VS 5HP ShopVac
www.youtube.com...

Below is a diagram of the Estes rocket motor construction

a reply to: neutronflux

5hp is the propeller power. You would need to know how much volume of fluid it can displeased per unit time.. The rocket produces way too much smoke for the shop vac to displace

originally posted by: NicSign
a reply to: neutronflux

5hp is the propeller power. You would need to know how much volume of fluid it can displeased per unit time.. The rocket produces way too much smoke for the shop vac to displace

You are so ridiculous

You talking about a rocket with a maximum thrust of 5 Newtons, that has an impulse of .25 Seconds, and only 2.3g of propellant, with a rocket motor diameter maybe a 3rd of the diameter of the suction hose, with the Shopvac continuously drawing a suction, and the Shopvac having a surge volume of 5 gallons and 6 foot of hose.

The photos show no spill over where the whopping .25 seconds impulse of thrust overwhelm the Shopvac’s ability to create suction in anyway.





You

The rocket produces way too much smoke for the shop vac to displace

Again, the burn was only .25 seconds. It was explained to you in another post the white smoke after the initial burn is tracking smoke. The rocket nozzle was well away from the suction hose before the Shopvac ever got a chance to draw in the tracking smoke. The diagram in the post you replied to shows after the propellant burn charge, there is a tracking smoke charge that provides no thrust.

You are soooo disingenuous.

You

Rockets require external resistance, like an atmosphere to push off of

What the hell was the small rocket motor pushing against with a constant “vacuum” at its nozzle, and no sign the Shopvac was overwhelmed in anyway. How did the rocket nozzle accelerate out of the “vacuum” without hesitation out of the suction hose.

Again. A 5HP Shopvac could not prevent the rocket from accelerating from Newton’s third law. Rockets work from the motive force of the release of kinetic energy from the reaction by the rocket fuels. Not because there is an atmosphere to push against

You have been debunked from everything from you complete misunderstanding of the reaction of fuel which gives the rocket it’s thrust and motive force, from shower heads, model rocket engines, pictures of the ISS, testimony by persons from ISS missions, services like satellite radio/TV/Internet/weather/phone, how a Dish TV satellite dish must be properly aligned to get a single, to videos of rockets launched into space, and mirrors/reflectors placed on the moon.

a reply to: NicSign

29 pages of this nonsense?

a reply to: oldcarpy

At least I get to build and play with rockets😄

a reply to: neutronflux

Build a really big one and you might be able to get it to hit the firmament/glass dome thing. Possibly.