Retanking in space by BEC beams

[rogers_buck]

Imagine a lunar bas with a big crator in a polar region that is constantly in darkness. Perhaps it is nearby a water source. At the rim is a solar power station and on the dark floor of the crater is a special cryotanks and equipment for creating large quantities of Bose Einstein Condensates (BEC). BSEs have a curious property whereby they can be reflected between two fields that act as mirrors. Eventually, the BSE will aquire enough energy to escape the barrier and will propogate as a coherent beam of aatoms in the BEC state. On the small lab scale, such beams of atmos have passed through grills in a manner exactly the same as laser beams through a hologram. On the scale that I am thinking about, the beam of atoms would be used to fuel a passing space ship.<br /><br />Suppose from LEO a mighty Mars tug burns all of its fuel to head on to Mars. Before it leaves earth vacinity, it intercepts a targeted beam of BEC Hydrogen and Oxygen which it diverts to its empty fuel tanks. <br /><br />Three questions come to mind.<br />1) What is the maximum imagineable scale of a BEC production method?<br />2) How energetic can a BEC beam be (km/sec)?<br />3) How far into space could a BEC beam of H and O propogate before dispersion effects destroy the BEC state?<br /><br />

 

[earth_bound_misfit]

Dunno about this BEC beams stuff. But the idea of a crater in the shade and the rim in sunlight sounds like a good place for a thermal siphon, where convection might be able to create juice. <div class="Discussion_UserSignature"> <p> </p><p> </p><p>----------------------------------------------------------------- </p><p>Wanna see this site looking like the old SDC uplink?</p><p>Go here to see how: <strong>SDC Eye saver </strong>  </p> </div>

 

[webtaz99]

I think you need to become a little more familiar with the extreme conditions needed to create BEC. It takes much more than low temperatures. <div class="Discussion_UserSignature"> </div>

 

[rogers_buck]

I've worked with cryo He before in IR detectors and appreciate that even with a vacuum pulled on it the BEC state is a long way away. Traps, laser cooling, etc., are all required to produce small quantities of BEC.<br /><br />Having said that, the difference between what is done in the lab with great effort in the here and now vs. what might be done in the future is simply an exersize in engineering. I don't think we can speak to the engineering in this thread but we can consider the physics.<br /><br />If the answers to my questions are theoretically compelling, then the engineering will take care of itself over time.<br /><br />But, if a BEC beam would be quickly scattered by environmental interractions, a thread on a brilliant way of engineering large quatities of BEC beams would have no application as I am suggesting.<br /><br />So, please, ignore the engineering an focus on the physics.<br /><br /> <br />

 

[webtaz99]

OK, here's some physics. The "temperature" of "empty space" , around 3K, is too hot to allow BEC to remain entangled.<br /><br />There is an alternative. Many plans exist to send a stream of hot plasma.<br /><br />Then there's this. <div class="Discussion_UserSignature"> </div>

 

[rogers_buck]

Good question. How exactly would a BEC beam interact with ambient photons is the krux of the question. Space is full of them.<br /><br />I don't know the answer, but I have a good idea how to find it out. To begin with, what would a BEC beam look like? To be stable at all it would likely need to use a trick.<br /><br />http://arxiv.org/ftp/cond-mat/papers/0204/0204532.pdf<br /><br />This paper describes the production of soliton trains of BECs, and our BEC beam might well only be possible as a soliton train. As in mundane optical applications like ultra-long haul fiber optics, solitons allow beams to resist disspersion effects by regenerating the perturbed waveform from neighboring states.<br /><br />Unless someone knows better, I think the interractions of ambient photons would produce scattering effects in a BEC beam, and the use of solitons to comprise the beam would make it able to withstand some of the quantum instabilities resulting from such interractions.<br /><br />Haven't a clue at the moment if that would be true at all, true for an inch, true for a 10000km. Not totally convinced that matter waves interract with photonic waves the same way as photonic waves interract with each other. I think understanding that is the nut to crack.<br />

 

[rogers_buck]

I like the laser driven bomblets. Haven't seen that before!<br />

 

[nexium]

Sorry, I know too little to comment on the BEC beam. I am impressed with the laser driven bomlets. Let's fund the solar powered lasers in solar orbit NOW. They can modify the orbit very gradually of Earth threatening "other solar system objects" formally known as asteroids and comets.<br />The magnetic sail will not work well, until we can get it beyond Saturn, as a superconducting ring many miles in diameter is needed, and we do not yet have high temperature superconductors. Can we keep the beam of micro sails from mostly missing the the superconducting ring at a range of one billion kilometers? Is a micro sail smaller than one millimeter. If so, it will be a difficult target for the star ships lasers.<br />Pilot model starships can explore "dwarf planets" beyond Saturn. Neil