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Not a pipe dream at all. The particles can be forced to never impact the wall of the tube, also.
Here we go again...
Problems:
1: MASSIVE energy requirement for ionization and beam acceleration to move even tiny quantities of gas.
2: Confinement magnets along the length of the tube will be required. The extreme weight of these magnets, their power demands, and the power transmission systems will weigh too much and the tube will simply snap and fall.
3: There is no practical way to capture the beam on the recieving end and neutralizing it without an electrical connection to the ground, 24,000 miles away. A HUGE cryogenic-sheathed superconducting cable would also be needed, adding even more weight to the elevator.
4: Bringing Liquid Nitrogen coolant up to keep the wire cold. No practical method other then elevator tankage.
I don't think that any practical carbon nanotube cable or pipe could possibly support such a system, and even then you would only be able to move a few grams a day.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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1: MASSIVE energy requirement for ionization and beam acceleration to move even tiny quantities of gas.
How much voltage and how many Amps?
2: Confinement magnets along the length of the tube will be required. The extreme weight of these magnets, their power demands, and the power transmission systems will weigh too much and the tube will simply snap and fall.
How about if you just place an oppsite charge on the tube?
3: There is no practical way to capture the beam on the recieving end and neutralizing it without an electrical connection to the ground, 24,000 miles away. A HUGE cryogenic-sheathed superconducting cable would also be needed, adding even more weight to the elevator.
How about neutralizing it on the other side with a beam of opossite charge?
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It will take a lot of energy then again it takes a lot of energy to get gas into space anyway and
electricity is cheaper then rockets. A neutral particle beam going up a tube will help pump gas up
a tube. Perhaps the beam could have a low enough velocity that when it gets to the top of the
tube its penetrating distance won't be to far. Perhaps on the other end aluminum could deflect and
cool the beam. I don't know evaporate liquid nitrogen on the other side of the aluminum sheet?
??? .
I think the biggest problem would be it melting the tube. Make the tube wide at first and
when the beam actually diverges enough to hit the tube hopefully its lost enough kinetic energy. I
think though it will likely have the same problem as most space elevators will likely have.
Simply not enough throughput to justify the cost of building it. However I am willing to study all
options.
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What would happen if you sucked all the air out of the tube from below?
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What would happen if you sucked all the air out of the tube from below?
You don’t really want to suck all the air out of the tube because if you do the outside air pressure will cause the tube to collapse. The air in the tube is accelerate anyway by the particle beam. Actually though you don’t really want a particle beam going through the tube because that might fry the tube. What you wanted is supper cooled methane (near zero Kelvin) flowing through the tube at supper sonic speed probably propagating as sine wave shaped shock waves where the low pressure is at one bar and the high pressure is 90 bars.
You first accelerate the cryogenic methane with regular pumps. You then use a piezoelectric pump to get it up to the speed of sound or faster and in the shape of wave packets. Finally you accelerate it by stripping electrons of it with a static or alternating field and accelerating the charged fluid through an electric field.
The biggest problem is because the charge is not uniform the electric field will cause some particles to move faster then others. Because temperature is related to the standard deviation of the velocity this means the temperature will rise. However the rising temperature will cause the shock wave packets to disperse (note the speed of sound at absolute zero is zero, and at absolute zero an ideal gas has zero viscosity) increasing the speed of sound and causing the wave fronts to propagate up the tube even faster. I think by this method it may be reasonable to get hydrogen all the way up the tube with one pump. Hopefully there will be enough umpff to get methane all the way up with one pump too.
BTW I don’t know if I am right to call these waves shockwaves. The initial wave fronts entering the tube will be shock waves until equilibrium settles and you have normal wave fronts and bulk flow.
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You don't really want to suck all the air out of the tube because if you do the outside air pressure will cause the tube to collapse.
Surly if it can withstand its own weight it should not collapse under the vacuum of space. Condensers at power plants can achieve almost 29" of vacuum.
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Its not the vacuum of space that would be a problem if you created a vacuum inside the tube though. You'd not only have to contend with the stress of a huge length of tube but the pressure pushing inwards from all around. That a lot of stress pushing in different directions on a small bit of tube.
Graeme
There was a young lady named Bright.
Whose speed was far faster than light;
She set out one day
in a relative way
And returned on the previous night.
--Arthur Buller--
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If you evacuated the tube would that not allow a particle beam to reach the top more easy since it does not have to go through an atmosphere???
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If you evacuated the tube would that not allow a particle beam to reach the top more easy since it does not have to go through an atmosphere???
A carbon nanotube pipe would be like a balloon. It would have tensile strength meaning it can resist being pulled apart by the gas in the tube but it does not have compressive strength. This means it cannot resist the air pushing in on the tube. It is the atmospheric pressure inside the tube that gives it the strength to keep the air from outside pushing in on the tube. If you made the walls to resist compressive forces they would be considerably thicker and weigh considerably more. The end result is the pipe/elevator would be even less economical then it is now. Besides a lower density of air/(particle beam in the tube) means a lower density of fluid being transferred, which means a lower mass flow. The goal is to maximize the mass flow for a given weight of (space elevator)/(pipe line)
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Can a carbon beryllium compound or carbon lithium compound nano tube be made to withstand these inward forces? They would be lighter than just a carbon nano tube.
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Can a carbon beryllium compound or carbon lithium compound nano tube be made to withstand these inward forces? They would be lighter than just a carbon nano tube.
If you engineer a material to withstand compressive loads on the tube it likely will not have the same tensile strength along the length of the tube thus you will need more of it to support the tube. Additional, designing such a material is another huge engineering hurdle which makes building such a pipeline in the near term that much less practical. I am willing to discuss super light weight material design in another thread but to discuss it to much further in this thread I think would be digressing from our main focus.
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I still think it would be able to withstand the inward forces as well as the outward forces.
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No Errorist, it will not work. John gave you a very good reason why it would not work and this could easily be debunked with an introductory course in material science. You can't claim something will work without doing the required homework; if you don't have the knowledge to tackle the problem, acquire it. There are many, many sources outside of "A Case for Mars" that can help in your quest.
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I know we spoke briefly on space elevators for moon use and that it would be possible with todays technology, well though I could not calculate any of this I was sure it would work best there from the little science knowledge that I have. Here is an article the speaks to this.
Going Up, Next Floor Elevating to the Moon
Pearson knew the technical challenges were formidable, so he wondered, "why not build an elevator on the Moon?"
On the Moon, the force of gravity is one sixth of what we feel here on Earth, and a space elevator cable is well within our current manufacturing technology. Stretch a cable up from the surface of the Moon, and you'd have an inexpensive method of delivering minerals and supplies into Earth orbit.
A lunar space elevator would work differently than one based on Earth. Unlike our own planet, which rotates every 24 hours, the Moon only turns on its axis once every 29 days; the same amount of time it takes to complete one orbit around the Earth. This is why we can only ever see one side of the Moon. The concept of geostationary orbit doesn't really make sense around the Moon.
There are, however, five places in the Earth-Moon system where you could put an object of low mass - like a satellite... or a space elevator counterweight - and have them remain stable with very little energy: the Earth-Moon Lagrange points. The L1 point, a spot approximately 58,000 km above the surface of the Moon, will work perfectly.
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ftlwright,
I am talking about building a (MACRO WORLD) pipline to space of about 1/4 inch inside diameter with the (MICRO WORLD) nano tube material.I want the gas to flow within the 1/4 inch(MACRO WORLD) opening.This is why I made the analogy with the conduit.
OOPS sorry wrong post!!!!
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NASA's Wildest Dreams well not really but could be used by the agency or anyone that has the cash.
The US space agency has plenty of big thinkers, but budget-challenging times like these tend to rein in their creativity. That's where the NASA Institute for Advanced Concepts comes in. This six-person center - operated by the independent Universities Space Research Association, not the government - hands out some $3 million a year.
Other technology think tank items other than a space elevator are:
LASER LIFTOFF laser powered rocket launch system
SPACE COWBOYS tethered orbital craft to moon launch and capture system
SELF-MADE MACHINES reconfigurable bots that can form complex machines
TRACTOR BEAMS from the futuristic but a main stay from the star trek series of shows
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John,
What was the best way to power these pumps on the pipeline? I forgot what you said before in a thread and I could not find it.
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John,
What was the best way to power these pumps on the pipeline? I forgot what you said before in a thread and I could not find it.
It depends on how many pumps you have. If you only have a few then you could target each one with a ground or space based laser or microwave beam. If you had a lot a RF wave guide would probably be the way to go.
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Bump.... This topic showed up during repair work ....
I'm hoping this discussion from 2004 might be of interest in 2022, with the advantage of 18 years of technology development.
As a general proposition, it appears that space elevators are impractical, if the technology used is based upon the cohesive forces of electric fields that hold matter together. Those forces are simply not strong enough to withstand the stress of an Earth level gravity field.
On the other hand, a tower built from the surface the Earth toward GEO would (presumably) squish into a puddle of deformed metal under those same forces.
However, what is ** not ** clear, and what seems to me worth study, is whether structures built to meet midway might survive the stresses of Earth's gravitational field.
Repair of this topic is ongoing, and will be completed in a couple of weeks.
(th)
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I see that the topic contains gaseous pressure
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For SpaceNut re #145
Thanks for picking up this "ancient" topic! I've been trying to make time to review this topic from the top, in hopes of seeing evidence anyone realized the pipe would burst due to the pressure that would be needed to push gas molecules to GEO, but so far I haven't found it. Instead, some NewMars members appear to have been beguiled by the Siren Song of the Space Elevator, which is impossible (on Earth) because the electric bonds of matter are not strong enough to withstand the forces that the Earth would generate.
My guess is the the exact same limitation would be observed if the pipe to GEO idea were attempted.
It ** should be ** be possible to model the Pipe to GEO idea mathematically.
The mass of the pipe must be carried by the gas molecules inside the pipe.
The first stage of the computation should be quite straight forward ...
Given a length of ordinary pipe (oil pipeline pipe is a good candidate) ...
We would know the mass of the pipe, and we would have the bursting strength (or that could be derived from research (I would hope)).
In the scenario, erect the pipe so it is vertical and hold it there with tie-downs.
Weld a cap on the top of the pipe.
Now pump air into the bottom of the pipe.
At some pressure, the force of the gas on the weld at the top will be sufficient to bear the entire weight of the pipe in a 1 G field.
From this opening procedure, we would have put into place everything needed to see how high the pipe could be extended before it bursts.
I'd expect an oil pipeline pipe could reach 1 mile in elevation before it bursts, but perhaps not.
In any case, this should be a simple exercise for a NewMars member ...
An ordinary spreadsheet should be able to perform the iterative calculations, by just pulling the formula cell down as the elevation of the pipe increases.
I invite everyone actively contributing to the forum to see how high they can lift a pipe using gas pressure.
The work needs to be done "in the open" so that the calculations can be performed by others, to reveal any flaws that might creep in. If a spreadsheet succeeds in modeling the pipe, we can make it available for others to study using the NewMars Dropbox account.
The tensile strength of the material to be used for the pipe wall is needed.
Note: This topic is in process of correction. Until work is finished, it is necessary to go to Post #1 and select Post Reply to write a new post.
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Google came up with suggestions for places to look for help computing the bursting pressure of pipe for this topic...
how compute burst pressure of pipeAll
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The formula is expressed as P=2St/D, where: P. pressure, psig.Barlow's Formula Calculator - Internal Pipe Pressure Capacityhttp://www.worldwidepipe.com › barlows-formula
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The 'Compute' button will calculate the burst and working pressures using Barlow's Equation, while 'Clear' will clear the form.
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1 psi (lb/in2) = 6,894.8 Pa (N/m2) = 6.895x10-2 bar · 1 MPa = 106 Pa.Burst Pressure Calculator - Zeus Industrial Productshttps://www.zeusinc.com › RESOURCES › Calculators
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I get the impression a gent named "Barlow" may have done some research in this area.
(th)
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I am reminded of another pipeline topic which had void content
Power Distribution by pipelines on Mars
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I'm hoping someone (besides me) is interested in studying the Pipeline aspect of this topic by John Creighton.
It seems to me that it is generally agreed that space elevators from GEO to Earth's surface are not going to happen due to the (relative) weakness of electron binding in ordinary materials.
Even the very best carbon structures cannot withstand the force of Earth's gravity.
I'd like to suggest that no one go down that rabbit hole....
On the ** other ** hand, John's pipeline tower idea has NOT been reduced to a rabbit hole.
The reason is compression .... materials under compression have a different problem to solve than materials under tension.
In both cases, ultimately the electron shell bindings are overcome.
What I believe (subject to correction of course) is that no one has studied the compression problem for a tower to GEO.
No doubt a serious, methodical study will reveal that the use of compression instead of tension would not make a practical difference.
This topic is a reasonably good fit for a serious study of the compression side of the problem.
***
One issue that comes up is the number of pumps...
There is no need for more than one pump, at the bottom of the tower.
Gas under pressure will distribute that pressure equitably over the entire distance to be covered, so there is no need for more than one pump.
A (relatively) simple spreadsheet should be able to show the gas pressure that would exist in a tower to GEO.
We already know exactly what the pressure on the bottom of a tower to 100 kilometers would be ... 15 psi (pounds per square inch).
If we enclose a volume of atmosphere in a tower, and admit additional molecules at the bottom, the total mass of gas in the cylinder will increase, and the volume will increase as well.
What would be of interest, if someone writes such a spreadsheet, is the pressure at 1 mile (or kilometer if you prefer) markers, as gas molecules are added at the bottom of the pipe.
I ** think ** this is a simple problem in physics, which I am hoping will be interesting for someone to solve.
My expectation is that the pipe will burst as molecules are added, for any materials known to science, but the details remain to be presented.
Another way of phrasing the question: How high could a tower be constructed in this scenario, before any material known to science exceeds its bursting point?
Point of clarification: A pipe to GEO would experience both compression AND tension loads.
The compression component derives from the mass of the pipe, bearing down on the foundation.
The tension component derives from the pressure of gas molecules inside the pipe exerting pressure on the inside wall of the pipe.
However, the tension component can be alleviated by increasing the mass of the side wall, at the expense of increasing the compression load.
In any case, I still believe (and hope) that a (relatively) simple spreadsheet should allow for calculation of the maximum height that might be achieved in this scenario, using materials known to science.
(th)
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Building a Martian space elevator would be complicated by the Martian moon Phobos, which is in a low orbit at ~6,028 km above the Martian surface and intersects the Equator regularly, thus getting in the way of a traditional geostationary space elevator. But there is an idea instead to build a space elevator from Phobos itself.
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