Spaceships of the Future: Visions of Interstellar Starship Travel

reply to post by TopsyTurvyOne


even in space, the whole motion of molecules being ejected from the single exit hole will result in a force even without combustion.. so even the jettison of waste will result in a force. anything, that accelerates from rest to any velocity has had a net force exerted on it. when the fuel mixture, which is kept in a higher pressure container is allowed to be released into space or vacuum it will provide a force as it moves out through the opening, even without combustion.

the difference between a balloon and a rocket is combustion. a rocket will ignite the fuel and oxidiser mixture to propel the exit of molecule even faster creating extra thrust. the shape of the cone is also designed to capture the rapid expansion so that it can concentrate the majority of it in one direction.

reply to post by Fisherr


With that mindset, yes sir, we have a long ways to go.

With a different mindset, it'll just take a couple of seconds to there and back again in less than 5 minutes.

reply to post by zazzafrazz


STAR TO YOU! Thanks for posting OP! I love this kind of sh**

reply to post by TopsyTurvyOne


Right well I think you need to play with a newton's cradle desk toy and think why do the balls swing away from the point of impact and not toward it as in essence that is exactly what you are proposing, for an in depth answer I suggest you read up on Sir Isaac Newton, you know the fellow with the story of an apple falling on his head and then look at more modern physics as I believe and no offence intended but you seem to not understand or you are simple asking Why as a metaphysical approach In which case I think we shall avoid the psychology of that as it is another thread that is unrelated to this.
I wish you well but Please try to understand basic physic's (Inertia and inertial displacement), good luck and best intentions'.

Yup I have looked at all them in the past.


Makes me wonder why we still focus on the chem rockets. Yeah they have there uses but why still use them once we break orbit

I nuclear propolusion engine could get a mars ship to its destination in a fraction of the time. Hell we could have a man on Titan!


As for those saying it wont reach other stars? No it wont well not for a few decades. But they would allow us to move around the solar system a lot quicker!

Which brings me to my next point. Poeple saying " we should'nt leave the planet until we sort our problems out"
Well one of the biggest problems we have is lack of resouces! Our solar system would supply all our needs for the next hundred years or more. There are so many riches just in near earth astroids alone And imagine if we could put our most eneviromentaly hazzardus industry on the moon? Or mars? That could solve alot of problems.

The biggest problem is the expense of getting things into orbit cheaply. Once we can do that we can build larger ships in orbit that can travel back and forth. And there are things in the pipe line to drive the cost down. But it all comes down to money..... if the USA cut its defence budget by half and put it into space explotation (yes explotation not exploration) they could build a space evlavator! The first country that builds a space elavator or a cheap launch device will be the first to tap into the solar systems riches and will be the next super power.

Originally posted by LevelEleven
reply to post by Diablos

 

YUP. These are a fantasy.

Why?

Originally posted by LABTECH767
reply to post by TopsyTurvyOne

 

Right well I think you need to play with a newton's cradle desk toy and think why do the balls swing away from the point of impact and not toward it as in essence that is exactly what you are proposing, for an in depth answer I suggest you read up on Sir Isaac Newton, you know the fellow with the story of an apple falling on his head and then look at more modern physics as I believe and no offence intended but you seem to not understand or you are simple asking Why as a metaphysical approach In which case I think we shall avoid the psychology of that as it is another thread that is unrelated to this.
I wish you well but Please try to understand basic physic's (Inertia and inertial displacement), good luck and best intentions'.

edit on 3-7-2013 by LABTECH767 because: (no reason given)

thank you for your kind words. what i am talking about has little to do with newton's cradle
but more with the behaviour of gasses in a vacuum. what did newton have to say
about that?
we know what happens to an air filled balloon when the air is released in our atmosphere.
what happens if you could drop that same air filled balloon into a complete vacuum
and then release the air (if you got the chance)?
a previous poster reckoned it would behave exactly the same. do you agree?

reply to post by TopsyTurvyOne


Well now we are going to get into some exotic quantumne theory, there is a theory called membrane theory, and another that is not independent but ties in called string theory or universal field theory that states everything in the universe (This time space continuum in which we live) is made of the same stuff even empty space and matter is just a waveform at right angles to the time space continuum, now that would suggest that gravity which may come from an underlying membrane somewhere else in superspace is permeating at a constant rate all this membrane but were matter represents a scrunched up bit more gravity exists in less volume so leaks out everywhere from there, anyway in this continuum no true vacuum exists, even in the best bell jar ever invented a true vacuum has never been produced and all we have been able to produce if low pressure and in essence that is what space is a region of extreme low pressure.

(As for the balloon, no it would move a hell of a lot faster as there is little external gas so the bulk of it's mass would be ejected in one direction imparting inertia in the opposite direction to the balloon material but in reality it would have to be one hell of a strong balloon to not pop as have you seen what happens to polystyrene when it is taken to the bottom of the ocean, well the opposite would happen to the balloon it would probably go in a much straighter line as well but in essence he is correct.)

The gas does not dissipate immediately and still has the effect of inertia in space and will continue primarily in the direction of it's ejection expanding in a cone like fashion outward under the effect of the lower surrounding pressure area, now what does the rocked push against, well it relies on the displacement of inertia to produce a forward or opposite to the direction of gas ejection motion, in the space the engine does produce relative to in the atmosphere less thrust but only marginally and the inertia on the rocked is reduced by not having the atmosphere to stop it's forward momentum.

Remember what I said about gravity, well as matter and energy travel inward to a black hole it is like the sheet or membrane of the universe is pulled taught un wrinkling the wave from or if you like scrunched up space that we perceive as matter. this over simplifies it but will have to do, good night and god bless it's late here.

Originally posted by LABTECH767
Right well I think you need to play with a newton's cradle desk toy and think why do the balls swing away from the point of impact and not toward it as in essence that is exactly what you are proposing...

Because there is an impact, which is force applied over time.

Since there is nothing in space to swing pendulum-like and strike the back of a spaceship, thus moving it forward, your proposed method of propulsion seems untenable.

On the other hand, if you are hanging at the end of a rope (pendulum-like) and have several cannonballs in your pockets, you can make the rope swing to the right by throwing a series of cannonballs to the left.

You are the spaceship. The cannonballs are the mass-possesing molecules of gas squirting out your behind.

Harte

reply to post by Harte


Sorry Harte this time you have the wrong end (no pun intended) of the rope, I was trying a simplistic method of trying to explain inertia to our fellow poster but I so agree 100 percent with you on that.
The analogy I was trying to get across to our friend was that the displacement of matter must (through the Newtonian conservation of energy explanation) be met with a opposite and opposing force, now weather in a vacuum or not that means that throwing stuff in one direction imparts motion on the thrower of that stuff equal to the mass times the acceleration and due to the low impedance due to low pressure and the virtual absence of gas the only resistive force is any present gravity and the innate inertia of the thrower. Essentially it is like a man in a space suit pushing against an object, now weather there is atmosphere or not he will move away from that object.

More advanced cosmology is as you know a contentious field and all theory remains just that, theory and can only be supported never proven absolutely (in pure science) but by that measure a theory can be disproven (most unpopular with physicists and other scientists and disciplines whom don't want to let go of long cherished ideas that they take to be given fact and explains why chaos theory became so popular in spite of the fact it is actually wrong but is used to explain complexity of interaction that our current mathematical models can not contain due to the vast variables).

Good to see your interest and I suspect you to also know one hell of a lot here.

Peace and good to see you posts again. (mine are admittedly often wacked out and rubbish)

Originally posted by LABTECH767
reply to post by Harte

 

Sorry Harte this time you have the wrong end (no pun intended) of the rope, I was trying a simplistic method of trying to explain inertia to our fellow poster but I so agree 100 percent with you on that.

I know, but your example made me realize another way of explaining it to him.

The poster Topsyturvyone appears to be thinking that for propulsion to ensue, the exiting gases must have something to "push against." Similar to how your foot pushes back against the ground to move you forward.

It's as if he thinks that this sort of pushing by gas on nearby atmosphere somehow produces the force on the craft. Like pushing off a wall or something.

Topsyturvetone has no inkling of, or has forgotten, the spacecraft is pushing the gas out, which is exactly like pushing against a wall. The fact that there is nothing in space for the gas to impact means absolutely nothing, but not in the poster's mind where, apparently, there is still some physical connection between the exiting gas and the rocket engine which would require the gas to push against something.

Harte

reply to post by choos


Spaceships are a nice way to travel the solar system. For another galaxy or star a wormhole would be a lot easier and maybe faster. The vastness of space really can be mind boggling to think about. Anyone seen the movie based on a book by Carl Sagan called contact? They build a device that creates a wormhole. Far fetched but if interstellar travel can be achieved that's one good way to do it if its possible in the future.

Originally posted by wlasikiewicz
reply to post by zazzafrazz

 

Good pictures, sad to say thats all that they will ever be.

Lol. hitting the nail on its head

Originally posted by Harte

Topsyturvetone has no inkling of, or has forgotten, the spacecraft is pushing the gas out, which is exactly like pushing against a wall. The fact that there is nothing in space for the gas to impact means absolutely nothing, but not in the poster's mind where, apparently, there is still some physical connection between the exiting gas and the rocket engine which would require the gas to push against something.

Harte

But of course there is. Combusting hot gas pushes against rocket nozzles.

Originally posted by mbkennel


But of course there is. Combusting hot gas pushes against rocket nozzles.

Yes that is how the thrust is generated and transfered to the rocket ship