Interstellar and intergalactic travel

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Norsefire, Jan 4, 2008.

  1. Saquist Banned Banned

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    Fascinating I'm guessing that means no FTL for the forseeable future.
    There most be better methods for creating antimatter.
     
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  3. orcot Valued Senior Member

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    anti matter does not allow FTL travel
     
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  5. Norsefire Salam Shalom Salom Registered Senior Member

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    We need to think outside the box, then. If we can't travel there quickly, then shorten the space between the two points!

    Since gravity manipulates space, we could figure some sort of way to, rather than travel there, simply warp there or shorten the travel distance via super-powerful black holes (my term for a black hole which is at least 1000 times stronger than a supermassive black hole)
     
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  7. kmguru Staff Member

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    Is there an otherside to a blackhole?
     
  8. orcot Valued Senior Member

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    Yes but it leads to the same hole.
     
  9. Saquist Banned Banned

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    space folding.
    I don't see how anything less that a black hole could do it. And that seems more impossible than breaking the light speed barrier.
     
  10. Norsefire Salam Shalom Salom Registered Senior Member

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    Assuming we figure out new and more efficient methods of propulsion, how would we go about colonizing space? I would think the smartest solution is paraterraforming, or domed cities on otherwise nonhabitable planets.

    Or, we could:

    terraforming
    space station cities

    And that's all I can think of. What else?
     
  11. eburacum45 Valued Senior Member

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    On arrival in a new system, you need to look for resources first; energy and raw materials. Energy can come from the local star, and you will need to build collection devices to gather that energy. Building such devices (either thermal or photovoltaic) requires raw materials, so you need a supply of those. If you are going to start your colonisation effort by building photocollection arrays then your first goal would probably be an asteroid, small moon or planet relatively near the local star.

    Alternately you might find a souce of fissile material in a small moon, asteroid or planet further from the star, this would give you access to energy from fission. If you have the technology level to build fusion power plants, energy could be obtained from deuterium or helium3, which could come from icy bodies or rings far from the local star.

    Gaining abundant energy in the outer part of a planetary system can be advantageous, because there is generally abundant water ice and nitrogen in such cold locations. If you want to grow food and biomass then the elements C,H,O, and N are essential. Only colonising the inner system might mean that some of these elements are hard to come by.

    But metals and silicon might be more abundant in the inner system, so you might want to start transporting raw materials around if necessary.

    Once you have a supply of energy and raw materials you can start building space colonies to live in. Gerard O'Neill made some interesting designs for such colonies- but no doub the designs will have evolved by the time interstellar colonisation is possible. It is entirely feasible for a colony in a new system to be entirely made up of space habitats; but if there are any suitable planets in the vicinity then they will almost certainly also be colonised.

    Some planets might be colonised by subterranean construction; some would have domed habitats, which could get so large that they could cover a respectable portion of the planet- this would be very similar to the concept of paraterraforming, which is described here
    http://en.wikipedia.org/wiki/Terraforming#Paraterraforming
    and some (perhaps very few) planets would be good candidates for full terraformation.

    I doubt that we will find any worlds which are already shirt-sleeve environments; if they are they will almost certainly become protected nature reserves.
     
    Last edited: Jan 29, 2008
  12. Norsefire Salam Shalom Salom Registered Senior Member

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    terraformation is impractical, expensive, and would take far too long. We also currently do not posess the technology levels needed to do that.

    Here's a question: if we find extraterrestrial non-intelligent life (but it'd be complex, like animals), and we had to eliminate it in order to colonize the planet, should we do so? I'd say yes, but that'd be controversial as a formal decision.
     
  13. eburacum45 Valued Senior Member

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    Why would we want to eliminate it? Rather than decimate the ecology of the alien world, we could live in space habitats in orbit around the planet and the local star, and visit the surface as required.

    Our biochemistry would probably be incompatible with the local biology anyway, so in order to successfully colonise such a world we would probably have to eliminate a major part of the biosphere. This would not really be a justifiable option.
     
  14. Saquist Banned Banned

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    How bout underground cities on unihabitable planets?
     
  15. kmguru Staff Member

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    Much more energy intensive, but doable. As long as there are food growth in the form of animals, fish, plants...people can survive and prosper. Humans lived through the iceage.

    Generational ships will work, if we know where we are going...

    If suddenly we have iceage, a lot of people will die here on Earth.
     
  16. Norsefire Salam Shalom Salom Registered Senior Member

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    And they suddenly become habitable underground? Perhaps warmer, but that isn't much incentive to pick an underground city over a domed city on the surface. In fact, a surface city would probably be the better choice for the solar energy and view.
     
  17. eburacum45 Valued Senior Member

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    Burying the habitat underground is advisable on airless planets and moons such as Mars, the Moon, Callisto, or Ganymede. Just a few metres down will suffice.These worlds each have almost no defence against solar wind particles or cosmic rays; the surface of such a world could support large expanses of light-gathering urface, and the light could then be piped underground to illuminate crops.
     
  18. kmguru Staff Member

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    Water in Moon?

    In 1994, the SDI-NASA Clementine spacecraft orbited the Moon and mapped its surface. In one experiment, Clementine beamed radio signals into shadowed craters near the Moon's south pole. The reflections, received by antennas on Earth, seemed to come from icy material.

    That makes sense. If there is water on the Moon, it's probably hiding in the permanent shadows of deep, cold craters, safe from vaporizing sunlight, frozen solid.

    So far so good, but... the Clementine data were not conclusive, and when astronomers tried to find ice in the same craters using the giant Arecibo radar in Puerto Rico, they couldn't. Maybe Clementine was somehow wrong.

    In 1998, NASA sent another spacecraft, Lunar Prospector, to check. Using a device called a neutron spectrometer, Lunar Prospector scanned the Moon's surface for hydrogen-rich minerals. Once again, polar craters yielded an intriguing signal: neutron ratios indicated hydrogen. Could it be the "H" in H2O? Many researchers think so.

    Lunar Prospector crashed, as planned, and several teams of researchers tried to detect that cloud, but without success. Either there was no water, or there was not enough water to be detected by Earth-based telescopes, or the telescopes were not looking in precisely the right place. In any event, no water was found from Prospector's impact.

    In 2008, NASA plans to send a new spacecraft to the Moon: the Lunar Reconnaissance Orbiter (LRO), bristling with advanced sensors that can sense water in at least four different ways. Scientists are hopeful that LRO can decide the question of Moon water once and for all.

    Our interest is not just scientific. If we are indeed to build a base on the Moon, the presence of water already there would offer a tremendous advantage in building and running it. It's been 35 years since we first set foot on the Moon. Now ambitious eyes once again look toward our satellite not just as a place to visit, but as a place to live.

    Link: http://science.nasa.gov/headlines/y2005/14apr_moonwater.htm
    --------------------------------

    If we have water in the Moon, underground shelter is a good idea....

    What about the vertical surface of a crater. Blast horizontally and make caves?
     
    Last edited: Jan 30, 2008
  19. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    As someone said - antimatter will not give you FTL.

    As for production - difficult to see how it can be produced quicker and/or stored easily. The power required for production is orders of magnitude less than the power the anti-matter actually can give you.

    But it possibly occurs naturally - although has never been detected - and any naturally occurring antimatter would annihilate on impact with the first matter it came in contact with.



    Only sensible method of intergalactic travel (if ANY method can be deemed sensible) with extrapolated current technology, are generation ships using the best propulsion systems available at the time, accelerating as long as possible (with some method of getting fuel on the way).
     
  20. orcot Valued Senior Member

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    extrapolated current technology in a real economy could only produce something of a starwasp. Then again their is always the change of a true genieus popping up somewhere, the next albert einstein or tesla FTL travel might not be all that impossible.
     
  21. Saquist Banned Banned

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    I was thinking radiation exposure. surface solar cells would still be an option but I think when constructing on the surface...whether it be a airless moon or asteroid, a thin aired planet like Mars, the option over the long run might be better to protect from asteroid impacts, freak weather anomolies or solar radiation.

    Geneational ships would for instance be continualy exposed to high levels of radiation.
     
  22. orcot Valued Senior Member

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    from witch source?

    I can understand why you would wan't to live underground on any smalltime base, but paraterraforming seem to simple
    The radiation levels on Mars are relative okay, and there is far enough material in the oort cloud to thicken it's atmosphere. And what abouth the loss of atmosphere? Even the moon could hold a 200 millibar enviroment for at least a 3 000 years that's long in human terms.
    This is far from being comfrable and no human could get outside without a space suit but it would be 20 times more dense then the martian atmosphere and block much of the dangerous radiation and it would disperse the temprature around the planet making less difference between day and night, also domes could be lighter because humans can tolerate a 300 millibar enviroment so you can make your domes real big while solar mirrors allow some plant live on it.

    If you can do this with the moon then you ca only wonder what you could do with mars
     
  23. Saquist Banned Banned

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    Cosmic and Solar Radiation are both intense in solar space and interplanetary space when considering the length of time of exposure.

    On planets radiation is a lesser problem because the atmosphere can absorb what ever isn't blocked by the planet's magnetic field.

    It was my understanding that the forseen moon base would not be station on the light side. I"m not sure if this was because of the issue of solar flares or heat exposure.
     

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