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  •  No really....no snark. (2+ / 0-)
    Recommended by:
    Horace Boothroyd III, Mollydog

    I don't think people realize how important the Sun is to living. I also don't think most people truly understand the distances involved in getting to the nearest star (let alone a nice cheery stable star like the one we enjoy).

    Given a 12 earth gravity acceleration (which would make you feel like silly putty thrown at the floor, how long do we suppose it would take to approach near light speeds? Then of course we would have to decelerate for an equal amount of time. I can imagine a few generations of  people living at 10 G's (hint: they'll have cankles that won't quit).

    Of course, if we could arrange to follow a black hole size mass that is traveling at near the speed of light and happens to be traveling the direction we want to go we wouldn't have to worry about acceleration and deceleration. All we would have to worry about then is staying far enough from the mass to not become a part of the singularity (think being smooshed really really small).

    My biggest criticism against meaningful space travel is a complete lack of intermediate steps between rocket power and "hyperspace". It's science fiction.....heavy on the fiction part.

    "First they ignore you, then they laugh at you, then they fight you, then you win." Mohandas Gandhi

    by 2dimeshift on Sun Dec 11, 2011 at 03:03:07 PM PST

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    •  And it's not really about propulsion, (1+ / 0-)
      Recommended by:
      Horace Boothroyd III

      I think it's more about dealing with the affects of gravity. Acceleration and deceleration. Even our stuff (think the vehicle) is subject to problems from this. You can only push an object so hard before it goes splat.

      "First they ignore you, then they laugh at you, then they fight you, then you win." Mohandas Gandhi

      by 2dimeshift on Sun Dec 11, 2011 at 03:11:11 PM PST

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    •  Actually, even a 1g acceleration (1+ / 0-)
      Recommended by:
      Horace Boothroyd III

      would be enough to reach anywhere in the universe within a single lifetime.  Of course, our sun might have already finished expanding by the time they got back.  Of course, that would require insane amounts of power.  Even the ship in Avatar which was only going on a 5 light year trip would require tens of thousands of terawatts (~800 just for the cargo alone assuming 100% efficiency) of power  for the laser array alone.  Worse, even 70% of light speed isn't nearly fast enough for time dilation to shorten the trip by very much.

      So yes, it is possible to get to any other star in a single lifetime but the power requirements would be insane.

      There is no saving throw against stupid.

      by Throw The Bums Out on Sun Dec 11, 2011 at 03:51:29 PM PST

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      •  I respectfully suggest you check your math. (1+ / 0-)
        Recommended by:
        Horace Boothroyd III

        I was wrong about the acceleration time, but I also forgot about the increase of relativistic mass as the vessel approaches near light speed.

        According to this site it would only take about a year to achieve 90% of the speed of light at 1g.

        "First they ignore you, then they laugh at you, then they fight you, then you win." Mohandas Gandhi

        by 2dimeshift on Sun Dec 11, 2011 at 04:01:50 PM PST

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        •  True, the power requirements would be (1+ / 0-)
          Recommended by:
          Horace Boothroyd III

          astronomical but the point was that you failed to take into account time dilation/length contraction when you asked "how long do you think it would take at a constant 10g acceleration".  As for the intermediate steps, a big one would be to cover a good portion of Mercury's surface with solar cells or other solar power generators as well as many large orbital (orbit of Mercury) solar power stations.  If you want a plan, here is a good start.

          1.  Use nuclear liberty rockets (more info here) to send up enough stuff to make space based solar power a practical reality

          2.  Use those same rockets to send up a real space station (in one or two parts) as well as all the components for a starting moonbase.

          3.  with a good solid space presence and plenty of power, start mining the moon and using those resources to build up our presence in space even ore

          4.  attempt to capture a small to medium asteroid and park it at a lagrange point for easy mining, repeating as necessary

          5.  construct a space station and manufacturing facility (with necessary protective equipment) in mercury orbit

          6.  start construction of the first mercury based power station.

          Of course, this doesn't cover all the other requirements such as building a laser array and finding a more efficient way of making and storing antimatter which would be necessary before launching the first relativistic starship .

          There is no saving throw against stupid.

          by Throw The Bums Out on Sun Dec 11, 2011 at 04:27:07 PM PST

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        •  The reason I suggest checking your math (1+ / 0-)
          Recommended by:
          Horace Boothroyd III

          is because the nearest Galaxy to ours (Andromeda) is 2.5 million light years away. Our galactic core is 27,200 ± 1,100 light years from our sun. The only way to reach the core in our lifetime at 1g acceleration would be if we were able to pass the speed of light.

          "First they ignore you, then they laugh at you, then they fight you, then you win." Mohandas Gandhi

          by 2dimeshift on Sun Dec 11, 2011 at 04:27:41 PM PST

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          •  Not true. As you approach the speed of light (2+ / 0-)
            Recommended by:
            Horace Boothroyd III, 2dimeshift

            time slows down (and/or the distance gets shorter depending on how you look at it) so you could reach Andromeda within a single lifetime (ship time, of course).

            There is no saving throw against stupid.

            by Throw The Bums Out on Sun Dec 11, 2011 at 05:12:16 PM PST

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            •  According to the site you cited even at 90% (0+ / 0-)

              the time contraction would only be around 1/3rd of what we would be feeling in "normal" relativity.  At that rate it would still feel like 7k years just to reach the galactic core. Obviously getting nearer to the speed of light would serve to decrease this even more, at the expense of much more energy.

              "First they ignore you, then they laugh at you, then they fight you, then you win." Mohandas Gandhi

              by 2dimeshift on Sun Dec 11, 2011 at 06:20:10 PM PST

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              •  I am talking about constant 1g acceleration until (0+ / 0-)

                you are halfway there and then flipping around and then a 1g deceleration until you arrive.  Yes, it would still take years but it would still happen within the lifetime of the crew (assuming they started at 21 or so) since the longer the trip the closer to light speed you would get before having to start slowing down.

                There is no saving throw against stupid.

                by Throw The Bums Out on Sun Dec 11, 2011 at 07:08:42 PM PST

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                •  You should also note that the site you (0+ / 0-)

                  referenced is a very cool physics heavy science fiction site. It's main purpose appears to be as a primer on how to right about the science of space travel convincingly in fictional stories.

                  I bookmarked it so I appreciate it but it has what the author of the site described as "handwavium".

                  "First they ignore you, then they laugh at you, then they fight you, then you win." Mohandas Gandhi

                  by 2dimeshift on Sun Dec 11, 2011 at 08:13:55 PM PST

                  [ Parent ]

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