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  1. Standard member sonhouse
    Fast and Curious
    02 Oct '13 17:10
    Like a trip to Alpha Centauri, 4 odd light years away, the ship only gets to 0.5c max. So it takes 6 months at one g to do that so you cover maybe 1/4 ly during acceleration run, same on decel, so you are doing 3.5 ly which takes 7 years so 8 years to get there, stay say 5 years, come back so you get back to Earth 21 years later of course full of new discoveries about AC and its planets. The 7 years at 0.5c would only get you about a 15% reduction in time, so you would save maybe 2 years so ship time would be about 19 years but 21 years goes by on Earth. Not a huge jump for the crew, if you left at age 20, you would be 39 coming back and your twin would be 41.

    So would you volunteer for such a trip? Since this would not be happening for at least 50 years in the future, it would be a good bet they would survive, since space craft design would be very safe by then, so would you go?
  2. 02 Oct '13 18:07
    Originally posted by sonhouse
    Like a trip to Alpha Centauri, 4 odd light years away, the ship only gets to 0.5c max. So it takes 6 months at one g to do that so you cover maybe 1/4 ly during acceleration run, same on decel, so you are doing 3.5 ly which takes 7 years so 8 years to get there, stay say 5 years, come back so you get back to Earth 21 years later of course full of new discov ...[text shortened]... od bet they would survive, since space craft design would be very safe by then, so would you go?
    That would depend on whether or not there was a habitable planet to visit there and who else would be going. Since it would take 21 years, one would have to look at it as a life more than a trip. I could see volunteering if you went or Hinds, but not with both of you together.
  3. Standard member sonhouse
    Fast and Curious
    02 Oct '13 18:10 / 1 edit
    Originally posted by joe beyser
    That would depend on whether or not there was a habitable planet to visit there and who else would be going. Since it would take 21 years, one would have to look at it as a life more than a trip. I could see volunteering if you went or Hinds, but not with both of you together.
    If it was a 2 man crew, it would be a 1 man crew upon arrival

    You would have thought they would have detected planets around the three suns of AC but not so far, which is weird since it is the closest star.

    The nice thing about going to AC is you get 3 for 1. 3 stars very close for the price of a trip to a star.

    I think it is a no-brainer as to which star to visit first.

    For trips that would take years like that, decades, it would behoove them to develop hibernation techniques to freeze your butt in cold storage so you don't consume anything, much of anything anyway, but that way you get to arrive at the same age as when you left so you could be 15 years younger than your twin when you get back home and wouldn't have been bored out of your skull. I would guess there would be exabytes of movies and educational material to study, maybe you could get a Phd in math or something.
  4. Standard member Soothfast
    0,1,1,2,3,5,8,13,21,
    03 Oct '13 00:05
    Originally posted by sonhouse
    Like a trip to Alpha Centauri, 4 odd light years away, the ship only gets to 0.5c max. So it takes 6 months at one g to do that so you cover maybe 1/4 ly during acceleration run, same on decel, so you are doing 3.5 ly which takes 7 years so 8 years to get there, stay say 5 years, come back so you get back to Earth 21 years later of course full of new discov ...[text shortened]... od bet they would survive, since space craft design would be very safe by then, so would you go?
    Free porn during the trip, I trust?
  5. Standard member sonhouse
    Fast and Curious
    03 Oct '13 07:17 / 1 edit
    Originally posted by Soothfast
    Free porn during the trip, I trust?
    Since they would be going at only half c, they could still communicate with Earth, information going both ways, one thing that would benefit Earth astronomers: Hubble strength telescopes on board would widen the long base astronomy image set for determining distances directly by parallax to further and further stars and galaxies so you wouldn't rely totally on doppler or standard candle readings. That would be valuable information so they could pay you back in kind, if you have, for instance, a great 3D printer on board, all the latest toys from Earth could just be printed and you would have the latest gadgets, TV broadcasts, porn if you wanted, lectures, all that would be possible. You could be the star of your own reality show and be making money back home that would be waiting for you when you get back and so forth.

    Right now the longest base we have for parallax is one side of Earth's orbit to another, taking pictures every 6 months for a base of 180 million miles. But even before you leave the solar system, you could be making a parallax base of billions of miles so for instance, at 180 billion miles out your parallax data would extend 1000 times further than it does now and so forth.
  6. 03 Oct '13 08:51
    Originally posted by sonhouse
    That would be valuable information so they could pay you back in kind, if you have, for instance, a great 3D printer on board, all the latest toys from Earth could just be printed and you would have the latest gadgets, TV broadcasts, porn if you wanted, lectures, all that would be possible.
    I doubt that a 3D printer will ever be able to print computer processors. I am not sure what type of toys you are thinking of, but for me, the latest and greatest computer is what I would want. Although maybe by then computers will be so fast we won't want anything faster. Of course if thats the case, then sign me up because due to time dilation I would get to play next years games this year!
    I don't buy into the whole 'when they come back' idea. I think such trips should be one way. There is no reason to make it a two way trip. If I am going to spend 20 years on a spaceship, it better be good enough to spend my whole life on.
  7. 03 Oct '13 11:47 / 6 edits
    Originally posted by sonhouse
    Like a trip to Alpha Centauri, 4 odd light years away, the ship only gets to 0.5c max. So it takes 6 months at one g to do that so you cover maybe 1/4 ly during acceleration run, same on decel, so you are doing 3.5 ly which takes 7 years so 8 years to get there, stay say 5 years, come back so you get back to Earth 21 years later of course full of new discov ...[text shortened]... od bet they would survive, since space craft design would be very safe by then, so would you go?
    I certainly would not go.
    Because of the confined space of the space ship, the journey there and back would be like a long stay in a prison.
    It also would mean I would be much older when I came back so much less years of my life would be spent on Earth and living on Earth would surely be like living in a huge paradise compared to living in the confines of a spaceship.

    I also just cannot believe that the journey can be made reasonably safe. Just for starters, there would be the problem of space dust and small space rocks that would hit the ship at the relative speed of up to half the speed of light! (if that's your top speed ). I once calculated that such collisions would be virtually inevitable for every one of even the shortest interstellar journeys. I also once calculated that any shielding, even a Whipple shield, if the ship cruises at 1/2 c, to protect the ship against such massively high-energy collisions could not be designed to be ridiculously unwieldy and massive and take up more than 99% of the mass of the whole ship else it wouldn't be strong enough to prevent a collision totally obliterating the ship.
    Anyone here got any ideas of what to do about that problem?
  8. Standard member sonhouse
    Fast and Curious
    03 Oct '13 12:14
    Originally posted by humy
    I certainly would not go.
    Because of the confined space of the space ship, the journey there and back would be like a long stay in a prison.
    It also would mean I would be much older when I came back so much less years of my life would be spent on Earth and living on Earth would surely be like living in a huge paradise compared to living in the confines of a s ...[text shortened]... ion totally obliterating the ship.
    Anyone here got any ideas of what to do about that problem?
    Magnetic deflection shields, superconducting so you don't need to keep replenishing the supply. I guess as deflections add up, the field would deplete but it can be pumped up again. Lidar with the ability to crank up the power to at least ionize bigger particles would prepare the rocks for the deflection shield. It the shield was strong, say 10 or 20 tesla's it should deflect most anything in its path.

    Since you only get about 0.85 change in time that alone would not be enough to get you back on Earth in a reasonable time, freezing/hibernation/cryo storage or something like that could keep you on ice for a hundred years or some such where you come out at the same age you went in biologically speaking, that way you don't spend much on food and water and filtration of waste products.

    That would be the way to go. All kinds of sci fi stories have been written about how some of the cryo caskets inevitably fail and you are left with only a certain number at the end of the journey. But who knows what technology will come about in space propulsion in the next 100 or 200 years.

    They might just have a good laugh when they read this kind of speculation, "boy, they didn't know about sub-tachyon flow which gave us interstellar flight at a million times the speed of light!"
  9. 03 Oct '13 12:18
    Originally posted by humy
    Anyone here got any ideas of what to do about that problem?
    I would certainly advocate sending robotic missions first. However I guess the problem would apply to that that too. I wonder how far out interstellar dust can be detected. Could a ship avoid collisions to some degree?
  10. 03 Oct '13 12:22
    I don't get why we would want to send humans in the first place. There are only three good reasons:
    1. To establish a colony. But that does not require a return journey.
    2. To do tasks that robots are not capable of. However I believe robots will be fully capable of such tasks before we are capable of interstellar flight.
    3. For the adventure. But why should the rest of us pay for a few lucky people to have fun, and why would such adventurous souls want to come back?
  11. Standard member sonhouse
    Fast and Curious
    03 Oct '13 12:29
    Originally posted by twhitehead
    I would certainly advocate sending robotic missions first. However I guess the problem would apply to that that too. I wonder how far out interstellar dust can be detected. Could a ship avoid collisions to some degree?
    Didn't you read my bit about magnetic deflection? You can magnetize a FROG if you have a strong enough field. Space rocks would deflect but you would need some high power laser for the bigger stuff or have thick shields, some suggested water ice in the front, thousands of tons of it. Some have designed systems where you have ten or so small asteroids hollowed out to be spacecraft in parallel with a much larger hollowed out asteroid that could act as the main city for the journey, where each small asteroid would have its own culture, one for Islam, one for Christians, one for Asians, and so forth while the big asteroid would be home for everyone.
  12. 03 Oct '13 17:08 / 3 edits
    Originally posted by sonhouse
    Magnetic deflection shields, superconducting so you don't need to keep replenishing the supply. I guess as deflections add up, the field would deplete but it can be pumped up again. Lidar with the ability to crank up the power to at least ionize bigger particles would prepare the rocks for the deflection shield. It the shield was strong, say 10 or 20 tesla' ...[text shortened]... about sub-tachyon flow which gave us interstellar flight at a million times the speed of light!"
    My only concern with using Magnetic deflection shields with superconductors is that I am not sure that, even with powerful superconductors, if it is possible to make one with such a powerful magnetic field that it could deflect a small lump of space rock from say, one millisecond light distance away (~300km away ), enough to make it miss the ship even though its relative speed to the ship is, say, 0.5c ! I mean, think about it; can a magmatic field from a superconductor have such a powerful sideways push on a lump of rock 300km away (but coming nearer ) that it can deflect it by as much as, say, 10 meters, in just the 2 milliseconds before it reaches the ship!?

    I don't know how to calculate this mathematically but I find this hard to imagine. I would guess you would need a magnetic field with a strength of that compatible with that of a neutron star!? -that's powerful enough to tear a lump of rock apart before it can even get close to the ship!
  13. Standard member sonhouse
    Fast and Curious
    03 Oct '13 17:33
    Originally posted by humy
    My only concern with using Magnetic deflection shields with superconductors is that I am not sure that, even with powerful superconductors, if it is possible to make one with such a powerful magnetic field that it could deflect a small lump of space rock from say, one millisecond light distance away (~300km away ), enough to make it miss the ship even though it ...[text shortened]... ? -that's powerful enough to tear a lump of rock apart before it can even get close to the ship!
    They won't be able to make that kind of field strength for sure but remember, the force is proportional to how fast the field is moving in regards to the object, when a magnet goes by an coil the induced current goes up the faster the interaction, so if a magnet is screaming by at half c the DI DT rate of the magnetic field is going to be something wondrous to behold. I would not be surprised a bit if you have a field strength of a couple hundred thousand gauss, 20 teslas, and the field is doing 150 km/sec, 150,000 meters per second, the rate of increase of field strength compared to the rock which for all intents and purposes is sitting still and the field is increasing at 6 microseconds per meter, you are going to have a very large effect on el rocko. It would be like hitting it with a sledge hammer. my guess is it would evaporate the rock and the individual ions, being much lighter would be amenable to being swept aside since now the individual particles are going to be nearly atomic in scale.
  14. 03 Oct '13 18:01
    Originally posted by sonhouse
    They won't be able to make that kind of field strength for sure but remember, the force is proportional to how fast the field is moving in regards to the object, when a magnet goes by an coil the induced current goes up the faster the interaction, so if a magnet is screaming by at half c the DI DT rate of the magnetic field is going to be something wondrous ...[text shortened]... to being swept aside since now the individual particles are going to be nearly atomic in scale.
    the force is proportional to how fast the field is moving in regards to the object,

    hey I forgot about that! Thanks for that So maybe a magnetic shield could work for this.
  15. Standard member wolfgang59
    Infidel
    03 Oct '13 19:20
    Originally posted by twhitehead
    [bIf I am going to spend 20 years on a spaceship, it better be good enough to spend my whole life on.[/b]
    It's a good point you make. But how does Earth (who have invested trillions
    into your journey) ensure payback? What incentive do you and your mates
    get to continue with research?

    20 years is a long time and as well as the adventure I think the crew would
    want big financial compensation and a means to spend it! Otherwise they
    go rogue!