Why do people say that rockets do not work in space?

Space lol you must be new here

What is space?

Liquid oxygen+ Liquid hydrogen+spark= propulsion. Pretty simple.

If it's that simple why do they compare rocket science to something that is too complicated for the average person to understand?

Hence the expression "it's not rocket science"

The concept/idea is simple.......application per need is the bitch.That's when the smarts come into play.

from what I gather, they say it's because space is a vacuum. with planes, the air resistance allows the craft to be steered/directed. in a vacuum, they say, the rocket would flail about wildly. also, due to the vacuum, there is no resistance for the rocket to push against to propel it in whatever direction is required.

I'm sure I missed something. any "no rockets in space" tards feel free to correct me

Like I said if you combine liquid O2 and H in a small space...out the other end comes force/propulsion....matters not whether in vacuum or pressure almost same result. Attitude control is done using small rockets mounted on Pitch, Yaw, and Roll Axis giving pilot/computer ability to steer craft. The space station even has them for orbit/attitude control.

Because they are trolls or tards.

The difference is purely academic.


And not just NASA.
There are a number of space agencies that can shoot stuff into space, not to mention private corporations that will launch your satellite into orbit for you if you pay them enough.


Because NASA isn't a private corporation.
Their employees are government workers getting paid on a government pay-scale.
Some of the brightest choose to work for NASA because they feel that doing interesting or challenging work is more important than high pay.

I know what you said; I read the thread before posting.

clearly you didn't comprehend "from what I gather" and "they say" in my post to infer I don't believe it

I love you Halcyon. (in purely a plutonic way)

People say rockets don't work in space because the scientist James Joule discovered that when gasses are allowed to expand into a vacuum they do no work. Obviously if you have a heat engine where the gases do no work you have an engine that doesn't work.

 

So rocket-deniers people who don't read to good and don't understand physics.
IOW Incorrigible scientific illiterates.

Hilarious, I have lost count of the number of times your scientific illiteracy has been shown up. You are no physicist or scientist. You are a third rate hack who's stock in trade is nothing more than sophistry.

That's cute coming from someone who doesn't understand what Joule meant with "free expansion."

Morans are funny.

Simple fact is that when your 'scientific understanding' leads you to a conclusion that is DEMONSTRABLY WRONG you must have made a mistake somewhere.
Rocket-deniers are completely unwilling to deal with that simple fact and adjust their error.
They're like flaties in that respect.


Last Edited by Halcyon Dayz, FCD on 07/15/2016 09:17 PM

Easy.

Mainstream science says space is a vacuum. That means no air, no gas, no particles.

Now, a thruster or rocket, HAS to have something for its exhaust to push against - ie the ground or atmosphere.

If a rocket is in a vacuum, then thrusters cannot work like they do in the ISS - which is not in space anyway, it is in a low Earth orbit.


So - anyone - how can a propulsion rocket thrust system possibly work in the vacuum of space?

A rocket works by conservation of momentum. In the absence of external forces, the center of mass of the combined rocket and propellant will not accelerate. Instead, the rocket and propellant push against each other with equal and opposite forces and will tend to move in opposite directions with equal and opposite momenta forever.

You're probably familiar with Newton's laws of motion, which include the equation

F = ma

However, the more complete statement is

F = dp/dt = d(mv)/dt = ma + (dm/dt)v

With no external forces, this means

F = 0
ma = -(dm/dt)v

dm/dt is the mass flow rate, which can be redefined as

dm/dt = (density)×(cross sectional area)×(velocity) = rho × A × v

Thus the force on the rocket is

m × a = -rho × A × v²

There's a lot more math involved in making an actual rocket, of course, but that's a starting point.

I think I learned that in about 2nd or 3rd grade.

You are alive in an amazing time. Pretty much anything you want to know you can find on the internet. You can find it explained a dozen ways. There is no excuse for being ignorant any longer. 90% of knowledge is available to you or me. The other 10% is being transcribed. Rocket science is well covered.

Basically the vacuum of space sucks the exhaust gas out of the nozzle faster than the exhaust can push against the sides of the nozzle to create pressure. No pressure differential means no significant lift.

Without pressure, The only lift in space would be the equivalent of a freight train try to propel itself along by shooting marbles out the back.

A freight train shooting marbles out the back, given time and enough marbles. would approach the speed of light.

Some don't understand how rockets work, some are just plain stupid.

The truth of the matter is that most rockets achieve necessary velocity for missions while in atmosphere. Minor correctives and adjustments are possible using the expulsion of compressed gases but this is in practical terms extremely limited. The confusion arises from the knee jerk reaction of otherwise scientifically literate individuals to acknowledge the limitations of space travel in terms of our ability to elevate mass out of the gravity well of earth and apply it usefully to masses in vacuum.

How many times did i see DMT in that post?

I can't remember

Exactly

In other words, you can push gases out at high speed but only insofar as you have a tank robust to contain the pressure and/or channel the pressure which means mass which means limitations to accelerating the mass you want moved which means there are real world physical limitations to moving spacecraft by any conventional means. Shills will not acknowledge this. Trolls will exploit this confusion. Same as it ever was.

Hahahahahahhahahahhaahhahahahahahahahhahahhahahahahah

Are you serious? Since when does a freight train or a rocket carry an infinite amount of mass.

All engines (including rockets, bicycles and guns) work by >>>concentrating<<< force.

Stop the rockets exhaust from piling up on top of itself as it is trying to escape the small nozzle hole and the rocket loses all its concentration of force and it goes nowhere. A vacuum stops this accumulation of force by sucking the gas out of the nozzle faster than escaping gas can "pile up".

Change the gearing on a push bike to 1:1 and you will go as fast as a walk.
Increase the gearing and thereby increase the pressure on the pedals and you will go much faster than a walk. Concentration of force.

Carve out a channel in the rifling of a gun, and see if the expanding gas (same as a rocket or combustion engine) can concentrate as much force on the bullet as normal. Concentration of force.

See if the explosion in a combustion engine can concentrate as much force on the wheels as normal, if the engine has faulty valves that reduce the pressure the cylinder can reach, thereby reducing the concentration of force.

make a rocket on your car and burn your tank of gas through the rocket, see how far you go. Probably a few feet compared to hundreds of miles you can burning it through the engine.
What is happening here????
Well the amount of pressure (concentration of force) the a given amount of fuel can build up in the cylinder is far greater than the pressure the equivalent amount of fuel can make at the base of the rocket.

long story short, space travel is as much myth as it is reality, thanks to hollywood spinmeisters.

Space is not a true vacuum, as in nothing there

How do you propose a vacuum, which is nothing, creates a force to "suck" anything?

Here is a simple explanation on the free expansion of gas.

[link to youtu.be (secure)]

In it you will see him, explain that 0 work was done (ie no force applied)

At the end you will see him calculate that because the volume doubled for which the gas to expand into, the pressure halved. If the expansion volume was infinite like space is supposed to be, then the pressure of any gas will be ZERO, or what ever pressure space is (for those dingbats that want to believe that space isn't a vacuum).

Strange, one thought just crossed my mind.

Are we being lied to?

What if space is not a vacuum?

What if it's really an ocean?

Kind of obeys the same rules of physics, and we are in an oxygen bubble as a planet.

Secrets, secrets, secrets!

tards be tardin'