Quote:
I know this one. I remember it from an old Stundie post that compared rockets to a can of silly string. The rocket doesn't actually push the exhaust out of the nozzle, so the walls don't matter. The vacuum instantly pulls the exhaust out of the rocket and into itself, so there's no thrust. ETA: Found it. Quote:
|
Quote:
|
It's not like you have to go to space to find a vacuum. This isn't some theoretical question we have to build a super collider the size of the moon to solve. This could be answered in any vacuum chamber here on Earth with Diet Coke and Mentos.
|
Quote:
|
Quote:
Any thrust would be the result of the exhaust pushing against the wall of the chamber, obviously. :rolleyes: |
The "NASA" rocket equation? I thought it was the Tsiolkovsky rocket equation.
Oh, I get it.... Tsiolkovsky was "in on it", a NASA shill, 62 years before NASA was even established. |
Quote:
|
Quote:
I didn't bother reading his attachment. Its sideways, and I have a sore neck this morning. |
Quote:
|
Maybe this should be moved to the Science section here, since that seem to be the place for crackpot science theories. I am not denying there is a conspiracy angle, but overall I think this should be dealt with as crackpot science.
|
Quote:
|
Quote:
|
We did an design exercise once to see whether you could pee with enough thrust to lift yourself off an asteroid.
|
The thing is, NASA (and other private companies) live-stream the launches, then afterwards the whole thing is available to view on youtube.
For instance, Northrop Grumman are sending up an Antares resupply mission to the ISS, launching in about 40 minutes from now. You can watch the live stream now, here. https://www.rocketlaunch.live/?filter=northrop-grumman They are prepping the rocket now, and you can actually watch it all the way up from 0m above ground to space. Go and look! |
Quote:
https://en.wikipedia.org/wiki/Tsiolk...ocket_equation |
Well one good thing has come from this thread. I’ve obviously accepted that rockets work in space, but I’ve never taken the time to understand how. Now I have a much better understanding, so thanks to Jay and others.
|
Quote:
|
Quote:
And I suppose I was being a bit pedantic; offhand I don't know of any real-world space propulsion systems* that aren't arguably using gas** for reaction mass. *Not including propulsion systems that don't have a traditional reaction mass, e.g. lightsails or clever ways to push off Earth's magnetic field. **in this context, "gas" includes traditional gas (e.g. N2), plasma, and streams of ionized noble gasses. |
Quote:
|
Quote:
I didn't take offense at your correction, BTW. |
Quote:
|
Quote:
Hans |
Quote:
|
"If NASA was willing to fake great accomplishments they'd have a second one by now." - xkcd.
|
Quote:
|
Btw. the atmospheric pressure actually plays role. It lowers efficiency of rocket engine, as the speed through the nozzle depends on difference between pressures inside the engine and outside. If there was enough outside pressure, the gasses would just stay inside, and no work would be done.
|
Quote:
No seriously who. I want in. |
Quote:
The gas is accelerated out of the rocket by pressure. Pressure is a force. Where is the opposing force to the pressure? ... I'll save some iterations (and predictable diversions) by answering the question. The force acts in two directions: 1) Against the gas, which is accelerated and leaves the rocket. What happens to the gas afterwards is essentially irrelevant. 2) Opposite, against the bottom of the combustion chamber. The force of this pressure is what propels the rocket. (actually it works in all directions, against the side walls of the chamber, but these forces cancel out.) Hans |
Don't do it. Don't get drug down into nitpicking the details when the core argument is fundamentally flawed.
He's trying to Jabba us. |
Don't believe rockets work in a vacuum?
Watch the demo
|
Quote:
But of course none of this ever happened because rockets are a lie. Or some such thing... |
Quote:
|
Quote:
|
Quote:
|
Quote:
|
Quote:
The thing is, you can do these experiments of thrust yourself. There are places where they can damn near make vaccuums for you, and you can find some pressurised container, make a whole in it, and see it move. So why are you wasting time on web forums rather than testing your idea? |
Quote:
|
Quote:
|
Quote:
Lifting something off a scale by drawing it upward into a vacuum immediately severs the coupling between the object and the scale. That much is obvious. However, put a giant scale underneath a rocket and measure the impingement force of its exhaust, and you will continue to get a reading as the rocket lifts off and stops weighing down the scale. Quote:
|
Here, just for grins, is a seriously similar thread at Cosmoquest, where we miss Jay Utah.
|
All times are GMT -7. The time now is 05:37 AM. |
Powered by vBulletin. Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
© 2015-24, TribeTech AB. All Rights Reserved.