| A more sublime way of making miniature black holes rather than slamming iron asteroids into each other might be the construction of giant lasers powered by the Sun. These could compress super cold matter much the way laser fusion reactors do. Perhaps we could actually mass produce these bizzare objects. We could then erect massive propulsion beams that can harness energies equivalent to megaton nuclear explosions every second to power starships and sail into the Oort Cloud, brake with mag sails in deep space, build space colonies of cometary material, and power them with matter fed into the "holes." The vastness of space would become habitable and any kind of matter could be used as fuel; not just hydrogen or helium 3. Could we ignite brown dwarfs with micro-black holes?? Brown dwarfs and rogue gas giant planets could become sources of matter for propulsion beams in deep space, enabling high speed travel throughout the Oort Cloud. Another possibility would be to construct large spheres, many kilometers in diameter, of laser crystals grown to immense size in outer space, and energize the lasers with radiation from the mini-BH. These could be the Excalibur stations whose pulses outshine the galaxy ever so briefly and illuminate space while compound optical telescopes and super sensitive electronic eyes scan and map objects in the interstellar abyss. Excalibur was of course the giant x-ray laser system powered by nuclear pulses from Sir Clarke's "Rendezvous with Rama" that made it possible to spot immense numbers of object in space to prevent impacts with Earth. I am not plagiarizing. I am making tribute to the Great Sir Arthur C. Clarke. His books have inspired me deeply from a very early age. Before I could read, back when I was a kindergartener, I looked at the plates in "The Making of a Moon" with great curiosity. Why would anyone want to colonize the Oort Cloud instead of remain close to the warm fires of the Sun or another star? Trillions of comets are one reason. There would be no shortage of materials for building space colonies surrounded by shells of ice for cosmic ray protection. It would simply be a fascinating place to dwell. Within a spherical space colony 1000 miles in diameter, probably to large for the inner system where tidal forces and gravity from other planets might put stress on it, and the ice would melt unless it was very far from the Sun anyway, there would be over three million square miles of area, as much as the lower 48 states. There might not be mountains and great canyons, but there could be forests, lakes and fields. With swarms of replicating robots such things could come to be in the future. Gravity, pressure, lighting intensity and daily/seasonal rythmns could all be tailored to the desires of the inhabitants. Such man and woman made worlds would be magical places, and there would be no need to displace indigent life on other worlds with Earthly life. Freeman Dyson was right when he suggested the comets as a place for a space civilization IMHO. Space travelers would not be limited to 10 year voyages to Tau Ceti or Epsilon Eridani. They could rove throughout the realm of the comets and vast numbers of artificial worlds teeming with life and cities of great splendor. Speaking of Freeman Dyson, he like Sir Clarke has been a big inspiration to all us space dreamers. What if Freeman Dyson wrote science fiction? What if more sci-fi writers spun yarns about comet civilizations, nuclear pulse ships and spheres around stars that nobody minds the construction of? While I don't think we will tap every last bit of stellar power from every star in the galaxy by surrounding them with so-called Dyson Spheres to support an ungodly large population, some stars may be harnessed this way, perhaps to power star ships or to power some kind of giant particle accelerator to make miniature black holes or some other purpose. |
| Earlier I envisioned immense devices with 300 km. solid containment spheres for the mini-BHs and 2000 km. long focusing coils. This was excessive. Coils that are a kilometer or so in diameter would be all that are necessary. The purpose of the coils would not be to accelerate the plasma beam; it will be jetting from the accretion disk at right angles of a spinning mini-BH at relativistic velocities. The coils merely control the mini-BH and cause it to point its plasma jets in the desired directions, if this is possible. We're dealing with wild speculation here! The minor planet sized containment sphere is totally unnecessary. My erroneous assumption was that most of the object's energy would be radiated in all directions and that this must be reflected back upon the mini-BH to heat the plasma and contain the mini-BH. In reality, most of the energy will escape in the polar plasma jets. There will be Bremsstralung and synchrotron radiation of an extent I cannot determine. This is only a rough sketch indicating the possibility of interstellar propulsion by this method. Physicists could elaborate in more detail and someday hard engineering data must be obtained. Instead of a solid radiation reflecting sphere a cage to which the coils are mounted that allows stray radiation to escape into space should be sufficient. It could be a few kilometers wide. If we need 5E28 joules to energize the mass beams then 2.5E21 watts is generated for 236 days. This is equivalent to the energy of 607,000 one megaton bombs every second! Perhaps one percent will radiate onto the griders of the cage and into surrounding space. If the spherical cage is two kilometers wide then radiation density at that distance will be (2.5E19 watts/12,560,000 square meters)= 2E12 watts/sq.m. If 80% of the radiation is reflected back then 400 billion watts or 400,000,000 kilowatts is absorbed by each square meter of cage inner surface area. Since one megajoule equals 238.8 kilocalories and the specific heat of uranium is 0.0278 kcal/deg kg the temperature of one cubic meter of uranium (19,100 kg) will rise by 180,000 degrees C. in one second. The cage would disintegrate in a flash! Moreover, uranium is a good radiation reflector but it will undergo fission when it is bombarded by neutrons from small thermonuclear explosions of compressed fusing matter in the mini-BH accretion disk. Nickel would be a better radiation reflector material as it will not undergo fission and is very common in stony-iron asteroids. If we make the cage 20 kilometers in diameter the radiation density ( assuming only1% of the total released by infalling matter radiates outward and the rest goes into the jets, wild assumptions on my part) will be 2E10 watts/sq.m. and if 20% is absorbed then 4,000,000 kilowatts heats each square meter of cage girder surface area and one cubic meter of nickel will heat up by 1011 deg. C in one second. (4,000 MJ*238.8)=955,200 kcal The specific heat capacity of nickel is 0.106 kcal/deg kg. Its thermal conductivity is 0.2 cal/deg cm s which is 3.5x better than uranium and 2/3s as good as tungsten. Tungsten seems it would be superior to nickel if a large enough source of it was found due to its high m.p. and heat conductivity, although it has a lower specific heat than nickel. Since nickel has a melting point of 1455 C. it will melt quickly without cooling. If the girders are one meter wide and three meters thick and contain heat pipes to distribute the heat through the girder rapidly then it will take about three seconds to increase temp by 1011 C. With active cooling systems and helium or CFCs flowing at high pressure through drilled passages in the cage girders and reflectors protecting the coils temperatures can be controlled. Large space radiators would dissipate the heat. This would be more feasible than building a 7.5 trillion ton nickel sphere 300 km. wide and three meters thick! And if we did build a 300 km. wide cage structure with one percent the mass of a solid sphere it would amass 75 billion tons, about the mass of an Island 3 space colony, and the radiation heating of the cage might be so low that simple passive heat pipes and radiators instead of high pressure active cooling systems could keep it from overheating and it would just glow in the infrared and probably be super reliable and last for thousands of years in the rust and corrosion free vacuum of space during which time it could propel thousands of Rama sized star carriers to other solar systems. A profound investment in interstellar travel infrastructure. Ten smaller beam projectors rated at one tenth as much power would each be about 100 km. diameter (10E0.5= 3.16) and each amass only 7.5 billion tons. A single stony iron asteroid about two kilometers diameter could provide enough iron and nickel (the cage would be steel made of asteroidal iron and carbon with a nickel reflective side) to build one of these. As for the YBCO coils, oxygen would be no problem and perhaps yttrium, copper and barium could be found in stony-iron asteroids, the core of Mercury, or some other elements could be used for the superconductors that are more common in the galaxy. The beam projector cage, coils and reflectors could always be made a little larger. Less matter could be fed to the mini-BH to reduce its power output. Reducing power output to one tenth or less and using ten or more devices to propell Rama would have several advantages. If one beam failed the others would still be in action. If there was a thermonuclear explosion and x-ray burst in the accretion disk that caused a fluctuation in beam strength it wouldn't make as much difference if nine other beams were providing the sum of propulsion power. Beam strength would remain fairly smooth. Finally, reducing power output would put less radiation heating and thermal stress on the structure. So far I have been discussing devices to propell a 25 million ton ship to 66%c. That's probably the biggest interstellar vehicle we'd ever build, if we even built one that large. Many smaller interstellar ships would be built before Rama and these would not need as powerful or as massive beam projectors. They could travel more slowly. At 33%c only one fourth as much energy is required. Remember, these pages are not a prophesy or a "what we ought to do" but mostly an imagination stretching "what we could do" in the future. I find this stimulating and I hope you do to, gentle reader. Power for the cooling pumps could come from turbines propelled by the hot gas as it exits the system. Some electricity might be generated also. Enormous MHD coils in the array of superconducting focusing coils might also generate electric power to run cooling systems and heavy attitude control gyros. The possibility of using multi-layered ceramic dielectric mirrors to reflect radiation is interesting. These mirrors can reflect 99% of laser light falling on them. Perhaps low incidence dielectric mirrors that can reflect the radiation from the accretion disk that doesn't go into the jets but spews out in all directions as well as Bremsstralung and synchrotron could be devised. We must also wonder about super dense matter. If we can use solar powered beams to send mag-sailed chunks of iron onto collision courses to form mini-BHs, we should be able to slam some masses together to make ultra-dense matter. What properties would ultra-dense matter have in the way of radiation reflectivity and melting points, specific heat capacity, etc. ? I would suspect that ultra dense matter would have higher heat conductivity at least. If an intense electric charge was applied to the walls of the cage and reflectors would the free electrons reflect more radiation? Could we even create magnetically contained electron plasmas that shield against all radiations and weigh next to nothing? And what about futuristic super ceramics with extremely high melting points that have more strength than nickel or nickel-steel and either reflect a wide spectrum of radiations or are simply transparent to a wide spectrum of radiations and don't absorb and heat up at all? In all likelihood we will understand physics of higher dimensions, inertia, the Higgs field, etc. so well in 1000 years that we don't need to acquire phenomenal energies to overcome mass and inertia. Remember, this is all done in fun and it is probable that I am like a 16th or 17th century thinker who dreams of giant hot air balloons lifting gondolas the size of large wooden ships and riding the trade winds across the Atlantic to the New World! However, we may find that mass and inertia are so fundamental that even if there is a way to dispell or neutralize the Higgs boson we just end up with atoms that fly apart and disintegrate, or the energies required to eliminate mass and inertia are so great that its a waste of time to bother doing so. Meanwhile, let's not forget why we are discussing beamed propulsion. The energies of starflight are so immense that some really huge propulsion devices are needed to drive ships up to high speeds. Fusion might reach 10%, possibly 20% c, and highly explosive antimatter might do the same. With beamed propulsion we can make our engines as big and powerful as we want, within the limits of large scale future space architecture, leave them in orbit at the system we are exiting or braking into on decelerating beams and not have to drag them along with the ship. A 20 km. wide driver is larger than Rama. Ten of these star drive machines even more so. It would be absurd to try to propell the engines if we don't have to. Miniature spinning black holes would emitt opposing beams. How could we make a rocket based on that without being absurd? Finally, the mass that's used to generate energy and the mass that actually serves as the motivating substance is enormous. Why build a ship with tanks filled with billions of tons of reaction mass that adds parasitic mass to the whole ship? Rockets suffer from a high degree of inefficiency because they have to lug all their own reaction mass which constitutes a large fraction of the ship. Beamed propulsion does not suffer from this limitation. Beamed propulsion is more efficient than the rocket and it makes it possible to propel massive, comfortable star ships in which people must live for years at a time up to higher speeds than can be achieved by rockets. Fusion rockets are okay for interplanetary flight, but beamed propulsion is just right for interstellar flight. Some will disagree, but that's how I see it. The rocket can be a real hang-up, like planetary chauvanism. |
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| One of the problems with charged particle beams is that protons and alpha particles will repel each other and the beam will disperse widely over distance. The positive particle beam must be neutralized with electron beams. Electrons will be "boiled" off huge metallic electrodes of asteroidal iron perhaps and accelerated with coils to equal velocity of the proton/a particle beam. Robotic ships will probably have to replace the electrodes regularly, unless the electrodes are really massive. When the neutral particles approach the Star Carriers they will be ionized by stern lasers on the vessels so that they will provide dynamic pressure to the Carrier's mag-sail magnetic field or magnetoplasmic bubble. It might be better to use dust particles of neutral mass rather than charged particles, if we can work that out. See: Nordley article. |
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| More Nutty Ideas |
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| ABOVE) Using nuclear bombs on the Moon to slam pieces of matter could produce very dense matter that has unusual properties. Could U238 "densitized" by this method make a better radiation reflector? What properties would densitized iron have? Could we make huge masses of artificial diamond from big blocks of carbon? Could we crystalize purified silicon then cut the block up into thin slabs with lasers to make solar panels for powersats and lunar power? What about super dense calcium, already a superior conductor of electricity than copper; or super dense aluminum or magnesium? |
| Comments about Comets |
| Thor's Hammer Perhaps there is a better way to energize star ship propulsion beams besides harvesting solar energy with the enormous RAVEN; a daunting construction task. Those who remember earlier, now deleted pages, know that the RAVEN was an enormous partial Dyson sphere surrounding the Sun. RAVEN stood for Relativistically Accelerated Vehicle Energizing Node. I decided that such a structure which would require dismantling much of the planet Mercury would be a crime against Nature and that even a civilization thousands of years ahead of ours would have difficulty building such a monster. Besides, there might be a better way. Read on. Smaller solar power complexes covering a few million square miles on Mercury or several tens of millions of square miles ( several thousand by several thousand mile solar energy collectors) in free space could be used to power propulsion beams that propel large chunks of asteroidal iron with magnetic sails up to high fractions of light speed and slam them into comets or asteroids. The impact compression could form mini-black holes that could be captured by robotic ships with huge magnetic scoops lying in wait near the target. If these little black holes spin they should form a magnetic field that arises from the accretion disk. They could be contained and oriented in magnetic fields and any kind of matter could be fed into them. As particalized or vaporized matter spirals into the voracious gravity well of the mini-BHs intense energy will be released and jets of energetic plasma will be propelled at right angles to the accretion disk. These jets of plasma could be directed with magnetic coils to form propulsion beams. Solar wind plasma, matter from captured comets or mass from planetary atmospheres could be harvested and fed to the miniature black holes. The mammoth RAVEN would not be necessary. A few thousand beam projectors orbiting the Sun, Venus, Titan, Saturn, Uranus and Neptune to propell starships of all sorts will be a big enough job, but not nearly as huge as the multimillion mile wide RAVEN with all its architectural intricacies and power distribution and transmission systems, not to mention the mining and refining of materials to build the RAVEN with. It will not be necessary to defend the mass beam projectors from the many comets that approach the Sun every year with the elaborate systems (giant lasers, radars to detect incoming comets and robotic ships with nuclear warheads to divert them, etc.) the RAVEN would require. The beam projectors would present a target several orders of magnitude smaller than the RAVEN and they would rarely be threatened by incoming comets. They could be maneuvered out of the way of comets on collision course, unlike the RAVEN. I still like to call a complex of propulsion beams orbiting a star a NODE, because it would be like a node in the spider's web of stars interconnected by the proplusion beams. It might also be possible to slam chunks of mag-sailed iron accelerated by solar powered particle beams or actual mass driver like devices from opposite sides of the Sun to make the mini-black holes. This way it would not be necessary to go into deep space to capture the objects. We might divert comets and asteroids on a collision course with inhabited planets, space colonies or one of the beam projectors by launching high speed chunks of mag-sailed iron on an intercept trajectory. Obviously, this kind of incredible engineering is centuries away. THOR's HAMMER, the slamming of mag-sailed multi-ton pieces of iron propelled to relativistic velocities by solar powered driver beams to create miniature black holes, may be far superior to the RAVEN. Once we have a few mass beams powered by miniature black holes, we can slam more comets and asteroids to make as many of these objects as we want. Depending on the economics of solar energy, fusion (protium, deuterium, helium 3), advanced fission, even antimatter; these objects may become the predominant source of power in the solar system and Oort Cloud. Fusion is about 0.7% efficient in terms of matter converted to energy. A black hole will convert 6% to 40% matter to energy depending on its rotation. In the dimness of the Oort Cloud, comet colonists could use mini-BH powered beams to propell beamriding mag-sailers through the depths of interstellar space at high speed with more efficiency than fusion powered driver beams and more safety than antimatter pulse powered ships. Starships from the inner system could travel to the outer limits of the Oort Cloud, brake with mag-sails, and return to the inner system under power from a beam near a comet colony cluster fed with pure hydrogen from the ice of the comet. Denizens of the Oort Cloud would not be isolated nor would they endure the limitations of comparatively low speed fission or fusion rocket propulsion. Miniature black hole powered propulsion beams could even work in orbit around red dwarfs orbited by gas giants or comets to supply mass to the beams if the small stars can provide only a small amount of light energy to solar powered beams. With these devices in orbit around several nearby stars and in interstellar space we could travel by mag-sail or magnetoplasma sail to extrasolar planets and roam amongst the comets and small worlds like Sedna and Varuna in deep space. Recent discoveries of worlds beyond Pluto have pushed back the traditional boundary of the solar system. Without a doubt other star systems are surrounded by billions of comets and small ice worlds. Within a few light years there are far more worlds than we ever imagined. Rather than travel all the way to Tau Ceti, about 10 light years away, in the hope of discovering a new Earth, we might build space colonies hundreds of miles in diameter in the interstellar reaches of space using materials from comets and various small planets "out there." With protium fusion and/or mini-black hole power life in these artificial worlds would be indistinguishable from life on Earth. In the calm air of a 100 mile diameter Bernal Sphere or O'Neil cylinder balloon borne islands could float safely. Even so, planets where we can watch another Sun rise and set that might be home to strange new lifeforms are hard to resist. |
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| ABOVE) A device for propelling ships smaller than Rama. Less mass is "fed" to the mini-BH so power isn't so great. Devices for propelling Rama would be larger. |
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| ABOVE) If dielectric mirrors can reflect 99% of radiation, cage is large enough, and low incidence rays are reflected well by nickel underlying mirror, the cage girders won't melt. Heat pipes conduct heat thousands of times better than copper. Combined with active cooling this should be effective. |
| Good links about heat pipes: http://www.lanl.gov/news/releases/archive/00-064.shtml http://www.unm.edu/~isnps/projects/ http://www.cheresources.com/htpipes.shtml |
| Some Nutty Devices |