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There is no physical limitation that prevents us from leaving Sol system. It is actually quite easy compared to other technical problems. We have atomic power t

There is no physical limitation that prevents us from leaving Sol system. It is actually quite easy compared to other technical problems. We have atomic power that can be source of energy for thousands of years and we have technology to build sustainable ecosystem and push it in a direction of another star (albeit very slowly). And we are also able to image other planets very precisely to something like kilometers per pixel through gravitational lensing. It is just that humanity is not very good at consensus to even not suffocate in our own home.

gambiting 6y ago
Yes, obviously - the problem is that there is no reason whatsoever to do it at the speeds that are currently thought to be physically possible.
- lmilcin 6y ago
  There is reason, but people automatically dismiss reasons that give payoff a) after they are already dead and b) to somebody else than their immediate family.
  - jfk13 6y ago
    "A society grows great when old men plant trees in whose shade they know they shall never sit."
- wongarsu 6y ago
  We can realistically each 5% the speed of light with nuclear pulse propulsion, giving a travel time of 80 years. That's not completely unreasonable, just insanely expensive with no clear payoff
  - aardvark179 6y ago
    We can reasonably send something to Alpha Centauri in 100 years assuming you can get the drive to work, but that’s the closest star to us, and Project Longshot was a design for an unmanned probe. Yes, the British Interplanetary Society did do a study on what a manned mission might be like, but they always seem to underestimate the biological problems of space flight. If you wanted to colonise a planet around a nearby star it would be a truly staggering undertaking, even getting the fuel for an unmanned probe probably require H3 mining of Jupiter.
    - hobscoop 6y ago
      Try H3 mining of Uranus or Neptune rather than Jupiter! The gravity well is much smaller.
- Lewton 6y ago
  Exactly, if we send anything now, it'll probably be overtaken by superior vessels within a couple of centuries
  - TeMPOraL 6y ago
    But if we don't send anything now, there will be no superior vessels in the next centuries! Progress on technology doesn't happen on paper - you need to iteratively build, test and improve designs to get where. You can't just leapfrog a century of novel space technologies, much like you can't write a large program on paper, only ever put it on a computer when it's done, and have it compile and work correctly from the first build.
ricardo81 6y ago
Radiation and micrometeoroids still seem to be an unsolved problem.
- lmilcin 6y ago
  No, it is not. At least as long as you don't want to get there too fast (which we can't do anyway currently). Dust is taken care by an ice shield in front of the craft. Radiation is taken care by a water jacket. Radiation is only a real problem in the vicinity of the star. The atmosphere we have on Earth is only necessary to block radiation that comes from Sun either directly or through solar winds. The radiation from sources outside solar system might be high energy particles an photons but has very low flux. The funny thing is, everybody focuses on technical issues where the biggest issue is most likely non technical and it is mostly about human health, physical response to lack of gravity and psychological to isolation.
  - ricardo81 6y ago
    Indeed regarding psychological issues, my current understanding it 10% the speed of light is feasible, so 40 years to the nearest system with no guarantees there's anywhere to call home. The water jacket is intriguing, but doesn't it require a tonnage that's never been lifted into space yet? Had me thinking about a space elevator taking water up into space and also alleviating sea levels (to the point where much more water would be exported to something other than the shield). It surely may be possible but involves risks and costs that no one is willing to take. Perhaps that balance of risk will change in the future.
    - lmilcin 6y ago
      It is assumed that any kind of ship like that would be assembled in space and if we can't do that we are most likely not ready yet. Water would be a good candidate for both shield and jacket for the simple reason it is readily available in space in huge amounts and doesn't have to be lifted from Earth. What is necessary is a single remotely controlled ship that will go far enough from Sun to be able to capture and steer one of the watery asteroids. The further you go the slower the orbits the less energy you need to dramatically alter course of any astronomical body. We don't even need to bring all that water to Earth. Instead, it might be cheaper to fly half-finished craft out, finish assembly by robotic means and then turn it into center of solar system. The craft could then gain velocity, use as many gravitational assists as possible on the way in and then back and pick up the crew before it leaves solar system for its journey.
layoutIfNeeded 6y ago
Kilometers per pixel? That doesn’t sound right. At that resolution Earth would be 12000 pixels wide...
- danbruc 6y ago
  But it is actually true, there are proposals to use the sun as a gravitational lens to take picture of planets hundreds of light-years away with resolutions of kilometers to tens of kilometers. Actually building such a telescope would however probably be very challenging with our current technology as it requires sending satellites far away from the sun, several times the current distance of Voyager 1. Here is the first article [1] my search found. I did not actually read this specific, so I have no idea whether it is any good but it should provide enough information to search for additional information. [1] https://www.airspacemag.com/daily-planet/ultimate-space-telescope-would-use-sun-lens-180962499/ https://www.airspacemag.com/daily-planet/ultimate-space-tele...
  - lmilcin 6y ago
    Yes. So it does not require any speculative technology that we may or may not ever possess, just put together what we currently have plus some amount of research that would normally be expected of a project this size plus huge budget plus huge amount of patience. This is just a case go get a budget and build it.
Koshkin 6y ago
So... If we can survive in an artificial environment for thousands of years, why we need another star at all?
- slfnflctd 6y ago
  To keep doing it for longer. Eventually, external resources would be required regardless. I'm not betting on the current human race being capable of this, though-- in my opinion, we will need to more or less become a different species for anything like civilization as we know it to survive over the very long term. Otherwise we will inevitably keep wasting too much energy on emotionally driven, incredibly stupid and violent conflicts with each other.
hawski 6y ago
What technology do we have to build sustainable ecosystem? I am only aware of various failed projects of biospheres or whatever.
- Retric 6y ago
  There is a hobby for creating sealed ecosystems in jars, with one example being sealed and stable since 1972. The hard part is making them habitable for mammals which aren’t very hardy, need a lot of food, and reproduce slowly.
  - hawski 6y ago
    That sounds like we do not have said technology.
    - Retric 6y ago
      It’s important to separate not having the specific design solution to a specific problem from not having solutions to closely related problems. We don’t know what the mass budget etc would look like for an interstellar colony ship. On the other hand several known designs mostly worked for humans to the point where using them would dramatically reduce the supplies needed for a long trip. But, none of them where operating on a zero G interstellar mission. Biosphere 2 for example depended on sunlight which would be missing, but they provided sufficient calories across several months which means it was also generated enough oxygen assuming it had been setup properly to begin with. They had a huge range of other their issues, and you would need a vastly larger population and much higher efficiency for such a trip. But, from what amounted to a publicity stunt it was surprisingly close to a working solution. https://en.wikipedia.org/wiki/BIOS-3 https://en.wikipedia.org/wiki/BIOS-3 on the other hand was a far less ambitious project that was much closer to a practical design even if they imported food and the longest experiment was 180 days, it was actually using artificial lights. PS: A more significant question is how to design hardware systems that could last for such a trip and what it would take to sustain things at the other side.
marcosdumay 6y ago
> We have atomic power that can be source of energy for thousands of years and we have technology to build sustainable ecosystem and push it in a direction of another star (albeit very slowly). We are missing the technology to build anything in space, and to create small (dozens to hundreds of km of radius) ecosystems capable of sustaining people. We really do not have the technical means for space exploration. The good news is that people are researching both, as improvements on them lead to profits here on Earth. So I do think we'll get there reasonably quickly.
- risyachka 6y ago
  >We are missing the technology to build anything in space This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems.
  - coldtea 6y ago
    >This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems. Isn't this "I'm sure" more wishful thinking than actual practical certainty though? We made no contract with anyone that we can build anything we want as a species...
- manmal 6y ago
  Why send live people if they will spend all their time in space anyway? Might be easier to send frozen germ cells and a nanny robot, to be raised when the target planet has been reached.
  - lolc 6y ago
    Hilarious idea that such advanced technology would be used to spread humans.
coldtea 6y ago
>There is no physical limitation that prevents us from leaving Sol system. That's part wishful thinking, part hand-waving. There are tons of practical limitations that prevents us from leaving the solar system based on the nature of space and physical laws. At best, we could get some "generational ships" out going to nowhere knows where exactly (it's not like we have some habitable planet to even aim to in mind, and the various "atmosphere-making" schemes are pie in the sky and require tens or hundreds of years, plus tons of resources in that "generational ship"), but even that is less likely than regression or extinction here...

gambiting 6y ago

Yes, obviously - the problem is that there is no reason whatsoever to do it at the speeds that are currently thought to be physically possible.

lmilcin 6y ago
There is reason, but people automatically dismiss reasons that give payoff a) after they are already dead and b) to somebody else than their immediate family.
- jfk13 6y ago
  "A society grows great when old men plant trees in whose shade they know they shall never sit."
wongarsu 6y ago
We can realistically each 5% the speed of light with nuclear pulse propulsion, giving a travel time of 80 years. That's not completely unreasonable, just insanely expensive with no clear payoff
- aardvark179 6y ago
  We can reasonably send something to Alpha Centauri in 100 years assuming you can get the drive to work, but that’s the closest star to us, and Project Longshot was a design for an unmanned probe. Yes, the British Interplanetary Society did do a study on what a manned mission might be like, but they always seem to underestimate the biological problems of space flight. If you wanted to colonise a planet around a nearby star it would be a truly staggering undertaking, even getting the fuel for an unmanned probe probably require H3 mining of Jupiter.
  - hobscoop 6y ago
    Try H3 mining of Uranus or Neptune rather than Jupiter! The gravity well is much smaller.
Lewton 6y ago
Exactly, if we send anything now, it'll probably be overtaken by superior vessels within a couple of centuries
- TeMPOraL 6y ago
  But if we don't send anything now, there will be no superior vessels in the next centuries! Progress on technology doesn't happen on paper - you need to iteratively build, test and improve designs to get where. You can't just leapfrog a century of novel space technologies, much like you can't write a large program on paper, only ever put it on a computer when it's done, and have it compile and work correctly from the first build.

ricardo81 6y ago

Radiation and micrometeoroids still seem to be an unsolved problem.

lmilcin 6y ago
No, it is not. At least as long as you don't want to get there too fast (which we can't do anyway currently). Dust is taken care by an ice shield in front of the craft. Radiation is taken care by a water jacket. Radiation is only a real problem in the vicinity of the star. The atmosphere we have on Earth is only necessary to block radiation that comes from Sun either directly or through solar winds. The radiation from sources outside solar system might be high energy particles an photons but has very low flux. The funny thing is, everybody focuses on technical issues where the biggest issue is most likely non technical and it is mostly about human health, physical response to lack of gravity and psychological to isolation.
- ricardo81 6y ago
  Indeed regarding psychological issues, my current understanding it 10% the speed of light is feasible, so 40 years to the nearest system with no guarantees there's anywhere to call home. The water jacket is intriguing, but doesn't it require a tonnage that's never been lifted into space yet? Had me thinking about a space elevator taking water up into space and also alleviating sea levels (to the point where much more water would be exported to something other than the shield). It surely may be possible but involves risks and costs that no one is willing to take. Perhaps that balance of risk will change in the future.
  - lmilcin 6y ago
    It is assumed that any kind of ship like that would be assembled in space and if we can't do that we are most likely not ready yet. Water would be a good candidate for both shield and jacket for the simple reason it is readily available in space in huge amounts and doesn't have to be lifted from Earth. What is necessary is a single remotely controlled ship that will go far enough from Sun to be able to capture and steer one of the watery asteroids. The further you go the slower the orbits the less energy you need to dramatically alter course of any astronomical body. We don't even need to bring all that water to Earth. Instead, it might be cheaper to fly half-finished craft out, finish assembly by robotic means and then turn it into center of solar system. The craft could then gain velocity, use as many gravitational assists as possible on the way in and then back and pick up the crew before it leaves solar system for its journey.

layoutIfNeeded 6y ago

Kilometers per pixel? That doesn’t sound right. At that resolution Earth would be 12000 pixels wide...

danbruc 6y ago
But it is actually true, there are proposals to use the sun as a gravitational lens to take picture of planets hundreds of light-years away with resolutions of kilometers to tens of kilometers. Actually building such a telescope would however probably be very challenging with our current technology as it requires sending satellites far away from the sun, several times the current distance of Voyager 1. Here is the first article [1] my search found. I did not actually read this specific, so I have no idea whether it is any good but it should provide enough information to search for additional information. [1] https://www.airspacemag.com/daily-planet/ultimate-space-telescope-would-use-sun-lens-180962499/ https://www.airspacemag.com/daily-planet/ultimate-space-tele...
- lmilcin 6y ago
  Yes. So it does not require any speculative technology that we may or may not ever possess, just put together what we currently have plus some amount of research that would normally be expected of a project this size plus huge budget plus huge amount of patience. This is just a case go get a budget and build it.

Koshkin 6y ago

So... If we can survive in an artificial environment for thousands of years, why we need another star at all?

slfnflctd 6y ago
To keep doing it for longer. Eventually, external resources would be required regardless. I'm not betting on the current human race being capable of this, though-- in my opinion, we will need to more or less become a different species for anything like civilization as we know it to survive over the very long term. Otherwise we will inevitably keep wasting too much energy on emotionally driven, incredibly stupid and violent conflicts with each other.

hawski 6y ago

What technology do we have to build sustainable ecosystem? I am only aware of various failed projects of biospheres or whatever.

Retric 6y ago
There is a hobby for creating sealed ecosystems in jars, with one example being sealed and stable since 1972. The hard part is making them habitable for mammals which aren’t very hardy, need a lot of food, and reproduce slowly.
- hawski 6y ago
  That sounds like we do not have said technology.
  - Retric 6y ago
    It’s important to separate not having the specific design solution to a specific problem from not having solutions to closely related problems. We don’t know what the mass budget etc would look like for an interstellar colony ship. On the other hand several known designs mostly worked for humans to the point where using them would dramatically reduce the supplies needed for a long trip. But, none of them where operating on a zero G interstellar mission. Biosphere 2 for example depended on sunlight which would be missing, but they provided sufficient calories across several months which means it was also generated enough oxygen assuming it had been setup properly to begin with. They had a huge range of other their issues, and you would need a vastly larger population and much higher efficiency for such a trip. But, from what amounted to a publicity stunt it was surprisingly close to a working solution. https://en.wikipedia.org/wiki/BIOS-3 https://en.wikipedia.org/wiki/BIOS-3 on the other hand was a far less ambitious project that was much closer to a practical design even if they imported food and the longest experiment was 180 days, it was actually using artificial lights. PS: A more significant question is how to design hardware systems that could last for such a trip and what it would take to sustain things at the other side.

marcosdumay 6y ago

> We have atomic power that can be source of energy for thousands of years and we have technology to build sustainable ecosystem and push it in a direction of another star (albeit very slowly). We are missing the technology to build anything in space, and to create small (dozens to hundreds of km of radius) ecosystems capable of sustaining people. We really do not have the technical means for space exploration. The good news is that people are researching both, as improvements on them lead to profits here on Earth. So I do think we'll get there reasonably quickly.

risyachka 6y ago
>We are missing the technology to build anything in space This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems.
- coldtea 6y ago
  >This is mainly because no one tries to do it. If the biggest countries decided that they want to build it - I am sure humanity will solve all technical problems. Isn't this "I'm sure" more wishful thinking than actual practical certainty though? We made no contract with anyone that we can build anything we want as a species...
manmal 6y ago
Why send live people if they will spend all their time in space anyway? Might be easier to send frozen germ cells and a nanny robot, to be raised when the target planet has been reached.
- lolc 6y ago
  Hilarious idea that such advanced technology would be used to spread humans.

coldtea 6y ago

>There is no physical limitation that prevents us from leaving Sol system. That's part wishful thinking, part hand-waving. There are tons of practical limitations that prevents us from leaving the solar system based on the nature of space and physical laws. At best, we could get some "generational ships" out going to nowhere knows where exactly (it's not like we have some habitable planet to even aim to in mind, and the various "atmosphere-making" schemes are pie in the sky and require tens or hundreds of years, plus tons of resources in that "generational ship"), but even that is less likely than regression or extinction here...