Interstellar and intergalactic travel

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

  1. eburacum45 Valued Senior Member

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    To quote Pink Floyd:
    "There is no dark side of the Moon."
    The Moon rotates once every 28 days, so any habitat would be exposed to sunlight and solar wind for around half of that time. Daytime on the Moon is around 14 times as long as on Earth.
     
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  3. Norsefire Salam Shalom Salom Registered Senior Member

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    Wormholes? Quantum particles are constantly jumping around the place. If we can replicate that and control our destination, which would be difficult, it would be very rewarding. Isn't the problem, however, the fact that it takes too much energy?


    Just out of curiousity, have we ever traveled 10% the speed of light?
     
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  5. eburacum45 Valued Senior Member

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    No. The fastest spacecraft made by humanity so far were the Helios probes, which whipped past the Sun at 250,000 kph. The speed of light is a billion kph, more or less, so the top speed acheived so far is a mere 0.04% of c.
     
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  7. Norsefire Salam Shalom Salom Registered Senior Member

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    That's....disapointing. Orion propulsion could reach 10% the speed of light, right? We must use that.
    The real annoyance is that I won't be alive to witness these great achievements and discoveries, and that's really why I want them to hurry up already.


    Would Zeta Reticuli be a good destination? It's not only relatively close, 39.9 light years away, but it also is a star system and is the supposed home of the greys and does contain a planet within the Goldilocks Zone. As good a place as any, but even at 10% of light, it'd still take centuries!

    Another question out of curiousity, why is it that nothing can go faster than light? Sure light is fastest, but why can nothing go faster?
    Can't Ion propulsion get damn near light speed if it is allowed enough time and resources to accelerate to that point? Negative acceleration would lengthen a trip, though, since you'll have to slow down as well before you reach a destination, but it's a far better bet than conventional rocket systems.

    How would colonies on other worlds be? A bunch of metal huts, where you really can't enjoy your time outside without breaking your back by the sheer amount of protection you need to carry? That's why paraterraforming is best, if it's large enough ( and it can expand), it would allow us to lead relatively normal lives. Does anyone know if there are plans for colonization anytime soon?
     
  8. Saquist Banned Banned

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    Not to be rude but I think most people here no that. We just don't see the other side. although I can understand how you thought that what I was talking about....When Nasa released there premise to return to the moon and the subsquent moon base it spoke of placing the base on the "dark side" or on or near the terminus I guess at what would be the north or south pole. I assumed this was to place the base at a location where the rotation was faster instead of the days and night of sun light.

    That's the part I'm fuzzy about....I'm not quite sure why I'm just theorizing.
     
  9. orcot Valued Senior Member

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    wouldn't it be near the poles t a peak of eternal light, there are places near the pole where you get a sort of midnight sun allowing the have a "near" constant supply of solar energy.

    alpha centauri is 4,3 LY away so let's say it's 10 times closer. Alpha centauri's suns are only 23 AU apart zeta reticuli's are 9000 AU apart and neither have confirmed planets.

    it depends on the surface conditions overpressure/underpressure/no pressure
    to hot/to cold/rotation/composition atmosphere/composition surface(ice).

    In general any innerplanet who has at least 300 millibar atmosphere and is not to hot could be verry friendly to the point that your space suit would become comparable with that of a diver, with surface cities comparable with those on earth except that they are eveloped under a giant sail that can indeed be giant because of lack of pressure difference (any rip in the tent would also not lead to decrompression).
     
  10. Saquist Banned Banned

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    Intresting point but wouldn't the sunlight be weaker coming in at an angle?
    For instance on Earth sunlight is weaker at the poles than at the equator because the rays are coming in at an angle instead of direct light. Correct me if I'm wrong...

    If I'm right they might as well set up at the sea of tranquillity.
     
  11. kmguru Staff Member

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    Can we not setup operation inside a crater and live in the vertical side of the crater?

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  12. Saquist Banned Banned

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    well that's kinda my original point...
    The moon is airless...what exactly would a solar flare do to the hardware and people on the surface of the moon say the flare was the size of that which hit during the Regan Presidency?
     
  13. Saquist Banned Banned

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    oh wait..."vertical"? You mean in the walls of the crater?! Fascinating,
    Would it be enough though....I do not know but i don't imagine it would require as much excavating.
     
  14. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    Two things to consider:

    1. The distance the sunlight is travelling... on our earth at the poles it has to travel 6,400km more than at the equator. But compared to the roughly 150,000,000 km that it travels to get to earth, the additional 6,400km is not going to be that important. (roughly 0.004% increase in distance).

    2. The atmosphere it travels through... If you assume the atmosphere is 50km thick, then at the equator the sun has to travel through only 50km, but at the equator it travels through an incredible 800km of atmosphere (unless my maths is way off!). I know the ozone layer is the main area of absorbing the UV, but this rough calculation gives some indication of the increased travel through the various layers of the atmosphere - roughly 15 times more for sunlight at the poles.

    Unfortunately on our own moon there is no such atmosphere - so this second consideration has no impact whatsoever, and it is purely on the distance travelled.
     
  15. eburacum45 Valued Senior Member

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    Also important is the angle of incidence of the sunlight. If the angle is very far from perpendicular, the energy of the sunlight will be spread out over a much larger area. You could collect solar power using raised collectors set at an angle, but bear in mind that these collectors will cast a shadow on any collectors directly behind, thus cutting down on the total energy received.
     
  16. cosmictraveler Be kind to yourself always. Valued Senior Member

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    It already has been proven that a biodome supporting life cannot be built today that could be used in space anywhere. Food, water, and all other essential supplies must be transported to wherever humans set up a spaceport. That's a very expensive way to live I'd say. Then if someone would need a doctor for a serious medical problem they would have to be transported back to Earth, another costly trip IF the astronaut/cosmonaut even lives that long due to his/her life threatning medical problems.
     
  17. Norsefire Salam Shalom Salom Registered Senior Member

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    I think Biodomes are the way to go, anyway.
    But onto the matter of travel, that's the biggest issue. Do you think Humanity will ever span another galaxy? the Cluster? The Universe?
     
  18. kmguru Staff Member

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    That is a Big unknown. However, if the following two conditions are met - then definitely.

    1. Our exponential growth in science and technology continues... Just look at the last 100 years vs. last 1000 years.

    2. Humanity survives at the same technology base from self-inflicted or natural disasters.
     
  19. Fraggle Rocker Staff Member

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    Just traveling to a distant star in our galaxy will require either:
    • 1. Finding a way to beat relativity, or
    • 2. Building a generation starship that works, which requires solving all the social problems.
    Our galaxy is 100,000 light years in diameter. IIRC intergalactic distances are about ten times that.

    Taking option 2., which is at least understandable with today's science, would require a million years to traverse the Milky Way and ten million years to get to its closest neighbor. (If you go fast enough you pick up some relativistic time dilation and that might shorten your trip by--what? a factor of fifty? Whoopee!) The oldest habitations we've built that are still standing are only about six thousand years old, and they're made out of nice durable rock, the same as our planet. The oldest more complex technology that still works is the Roman aqueducts, and they're barely two thousand years old.

    Can we build something--can anybody build something!--that will last ten million years, in an environment that is guaranteed not to provide spare parts and spare tools whose needs were not anticipated?
     
  20. kmguru Staff Member

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    That is an engineer's nightmare. Metals could lose their cohesion. How about sometype of organic structure that repairs itself? Or may be when we have nano-technology that can constantly repair the ship?

    By the way, in ten million years, humans could evolve or de-evolve to something while in transit....likes of Red Dwarf?
     
  21. Saquist Banned Banned

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    I suspected as much but I couldn't be for certain.
    No ones really addressed how much shielding would be needed for intense solar flare activity though.
     
  22. orcot Valued Senior Member

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    ... If trips would take million of years, would it be possible to make slight adjustments to the stars itself that would in a matter of millions year result in a more or less controlled stellar collision with perhaps a massive dark hole flyby that would blast the star out of the milky way in a more our less controlled fashion to a preselected target while still carrying it's planetary system with it. With it's inhabiatants
     

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