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Hey, here is another thought. What if you shot a particle beam of hydrogen up the tube with out it hitting the sides?
That would suggest using a great amount of energy and some device for focusing the beam of molecules. By the time you've taken into account the amount of energy required to shoot the molecules and the cost of making a device to focus a beam over such a considerable distance you'd spent more than our lifetime worth of rocket based transportation.
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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Ok, cap the end of the tube that is just above sea level. Since the other end of the tube is still in space the whole inside of the tube is now under a vacuum. Correct????? Right????
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Ok, cap the end of the tube that is just above sea level. Since the other end of the tube is still in space the whole inside of the tube is now under a vacuum. Correct????? Right????
Only if inside the tube already had a vacuum in it, otherwise it would be full of air (or whatever molecule you'd pumped into it first).
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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You would be waiting for the better part of the rest of your life to move one tube full, plus now you no longer have energy-balenced system without warm gas at the bottom... the gas leaving the top carries away heat, which will cool that near the bottom and reduce the flow even more.
[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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You start out with both ends open, and full of air, and space. Now, cap the bottom end with the end in space still open. What is the air pressure now inside the tube at both ends?
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Chicken and egg problem... how do you fill the entire tube in the first place? Ship the gas in from the top?
If you did, then some of the gas would effuse out from the top, but the majority of it that is below escape velocity (way above 99%) would fall back to the Earth and assume similar pressure as the outside air, because of gravity.
[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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What is the pressure in the tube now that the bottom end is capped?
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The pressure would rise and most of the gas would collapse back down the tube, just like the atmosphere on Venus, no signifigant gas would escape because of its low velocity, save for a little near the top.
[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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Ok, What would happen if you pulled a near perfect vacuum inside the tube with both ends capped, and then placed the tube in its place through the atmosphere, and then opened the top end?
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Um, nothing would happen, since no gas could enter the tube... there isn't any at the top in the vacuum of space. What may happen though, is the air pressure in the atmosphere might crush the evacuated tube.
[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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Nope, Nano tubes are up to the task if the wall thickness is enough. If you admit the H2 at the bottom at this point what would happen?
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The gas would rush in and pressure will equalize depending on how much you allow, but the height of the gas will not substantially exceed that of the atmosphere... again, due to gravity.
[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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So at that point we just keep pumping it in untill it comes out the top. Will that work????
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No, see other thread.
"No, it will just collect at the bottom and the pressure will rise. You would have to apply a huge amount of pressure to ever get anywhere near the top, more than enough to destroy the system... Look at Venus, aproximatly the same gravity, but its atmosphere is a hundred times the pressure, not a hundred times as HIGH. "
[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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Suppose the open end in space is just a few hundred miles in space? Not 24,000 miles.
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Essentially zero is still essentially zero, the tube would have to be so short the atmosphere would be a problem. Plus, if the other end is not in geostationary orbit, then the Earth side end will move... FAST. This would preclude attaching it to the ground, and even a low-supersonic airplane would not be fast enough... the tube would simply snap.
[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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We are talking about a perfect geostationy orbit system.
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the pressure at sea level of a 200 KM column of H2 gas is 2 kg per square centimeter- this is a rough estimate, because I used the density of H2 at one atmosphere, but in this case it would be 0 pressure at the top and almost two atmospheres at the bottom. The actual pressure at sealevel should be less than 1.79 kg/cm^2, or 1.73 atmospheres. The point is that by adding some amount of hydrogen to the bottom of the tube, the pressure wave will travel to the top and an equal amount of H2 will be pumped to the top. All this requires is a pump with a pressure of two or three atmospheres, which is easy to build.
Since the hydrogen is supposedly isolated from the atmosphere, the air pressure outside the tube doesn't matter at all.
Using the air pressure at sea level to push H2 up is impossible because that would add air to the pure H2...
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Sorry, I didn't realise you guys wanted to pump H2 waaayyyy up there. Then centripetal acceleration becomes a factor at 35000 km, I think...
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Field Marshal Mathers,
Hey that pump could be solar powered also, correct? So not impossible?
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Unfortunatly, the tube must be around 30,000 kilometers long all the way out to stationary orbit, which will raise the pressure needed exponentially... Why doesn't the atmosphere of Venus suddenly blow away? It is under fantastic pressure after all... gravity always wins in the end.
I also don't know about your pressure estimate, since the density of a gas will increase with pressure... hence, gravity will cause a much bigger increase in pressure I believe at the bottom of the tube, and limit that near the top.
[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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you just take half the pressure at the bottom and use it as the average, since the pressure at the top is near zero. Then use that pressure for the whole tube. of course there is error because the pressure at the bottom is based on one atmosphere. Every time you recalculate with the new average pressure you increase your accuracy.
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Field Marshal Mathers,
So where would be the best place to install the pump?
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Unfortunatly, your key assumption - density remains that at 1atm pressure over the average, is incorrect. Hydrogen is a compressable gas, not an incompressable liquid. Hence, the gas will be at a considerably higher pressure at the base, and further injection by pump will only serve to increase the pressure there, not to eject the gas out of the end of the tube. A gas does not behave like a liquid does in pressure calculations because it is mostly empty space.
Further, simply raising the pressure does not circumvent the kenetics of the molecules: gravity will still confine the gas molecules that do not reach escape velocity to Earth's gravity, simply increasing the pressure only increases the number of molecules per volume, it does not increase their velocity.
[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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Any increase at the bottom should send H2 out the top. Gravity does not confine H2 to our atmosphere.So why would it inside the tube?
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