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There is model for flight on Earth: birds. Humans achieved a similar feat through mimicry and the use of fossil fuels. There is no model for instellar transit.

There is model for flight on Earth: birds. Humans achieved a similar feat through mimicry and the use of fossil fuels. There is no model for instellar transit. I am not optimistic that we can develop a technology that can speed transport between stars to such a degree before we destroy ourselves like every other hominid that has ever existed.

dheera 5y ago
Planes work quite differently from birds. We were inspired by them, but we didn't copy them at all. Attempts in the past to copy birds mostly failed. We got to the moon, Mars, and several other solar system bodies in the past half century without any mimicry. Maybe you don't, but I have very strong optimism for technological advancement, and also for modifying our life form to rid ourselves of our tendency to destroy things before heading to other stars. When I say "we" will go to other stars, it won't be Homo sapiens, but another species that we will create as our successor.
- OmicronCeti 5y ago
  The distance to the moon and Mars is absolutely trivial compared to even the closest star: to Mars is 0.0007% of the way to Alpha Centauri. >We got to the moon, Mars, and several other solar system bodies You're conflating humans and probes, which are vastly different.
  - dheera 5y ago
    > You're conflating humans and probes, which are vastly different. I disagree. Robots can build infrastructure far ahead of human settlement, such that everything already exists when we are ready to travel. We can also potentially re-engineer our own life form, or create an entirely new inorganic lifeform, to withstand various conditions, including radiation and a wider range of temperatures. That will be our successor. We are only beginning to understand genetics in the past decade. We have a long, long way to go, and a lot to understand. Science is still at its infancy. Also, this is something I could never say in an academic context, but deep down I don't believe in conservation of energy, partly because the big bang itself violates it. Yes, I would be ridiculed for saying this in a scientific context, but so would someone in the 1500s for saying that the Earth goes around the sun. I think at some point in the distant future we will not be reliant on stars as our energy source.
    - OmicronCeti 5y ago
      'we' did not go to Mars, 'we' did not go to pluto. We sent cameras with walky-talkies. That is so vastly different than sending people to the moon, that it's not really something we can disagree on in good faith. If you truly do not believe in the conservation of energy, I think we're done here since none of my arguments will be good enough for such wild speculation.
      - dheera 5y ago
        If we can send cameras with walky-talkies, we can invent and send (possibly silicon-based) life forms that will carry on our legacy while being a lot more resistant to the elements, require much less support along the journey, and can tolerate whatever gases and radiation may be present at the destination while still reproducing and carrying on society just as life does now. Human bodies suck because they need to eat, need to poop, complain if what they eat isn't tasty, fight with each other, and get cancer, but our legacy as intelligent life doesn't need to continue in our current carbon-based meat bag form.
        OmicronCeti 5y ago
        I can't believe I'm entertaining a reply, but how would a human-invented lifeform sent to the stars carry on human society if it is a) not human, and b) light years spatially distance and thousands of years temporally distant? This reads like an ungrad astronomy major fever dream.
        dheera 5y ago
        It would carry on our legacy as intelligent life. I don't think maintaining our current iteration in evolution is a condition that should be valued. We can evolve, or invent another life form that carries our civilization forward. Yes, it reads like a dream. Technological breakthroughs of the past were created by people with dreams, not by skeptics.
        natch 5y ago
        The question “what makes us human” is a deep one that has vexed philosophers for a long time. I don’t have the answer. If you have the answer, forgive me if I take it with a grain of salt. I do think it’s possible that our best hope for navigating the transition beyond the singularity involves transplanting our humanness to another kind of life form. I’m not necessarily talking about uploading… more about a staggered intergenerational transition mixed in with life as we know it. I realize that to some people, this will continue to sound like crazy talk, until one day it isn’t. It’s ok if you are one of those people :-).
  - valuearb 5y ago
    We didn’t land on the moon?
  - lmm 5y ago
    LEO is 0.0005% of the way to the Moon, and yet once we'd done the first it didn't take us long to scale up to the second.
    - OmicronCeti 5y ago
      That's simply a facile comparison because most of the fuel is needed to get out of the atmosphere. The energy required for that 0.0005% distance is nearly 66% of the total. Let's say it takes ~8 minutes to get to LEO vs 4,380 minutes to get to the Moon. That's a factor of ~550x longer flight time for a distance 2000x further. Alpha Centauri is 1500x further away than Mars. It currently takes ~7 months to go from Earth to Mars (at 25,000 mph), assuming similar scaling that comes out to only 400x the flight time, or just about 230 years.
- throwawayboise 5y ago
  We got to the moon. 12 humans have walked on it. Note that 50 years later, nobody is living there, or working there. Nobody has even returned. We may get humans to Mars. It's technically possible. But I don't think we will ever live there.
  - dheera 5y ago
    50 years isn't a long time. I'm sure some dude said the same thing about Tibet being too harsh to live in, and yet there are cities there now.
    - OmicronCeti 5y ago
      What are you talking about? People have lived in Tibet for 20,000+ years?
  - OmicronCeti 5y ago
    The person you're replying to stated elsewhere that they don't believe in the conservation of energy, so (ironically) save yourself the energy of arguing with them.
    - chub500 5y ago
      Not to detract from your sarcasm but the conservation of energy only holds true in flat spacetime. So I guess you don't 'believe' in curved spacetime? That makes you a flat spacetimer I guess...
kortilla 5y ago
The breakthroughs in flying came when we stopped trying to make machines look like birds. Submarines work well because we didn’t bother making them anything like fish.
rbanffy 5y ago
> There is no model for instellar transit. There is, but extrasolar objects don't have engines and do very low energy transits. We'd need a large habitat, a power source that can last for a couple thousand years and a lot - and I mean a LOT - of reaction mass to accelerate it and to brake it when it arrives at its destination. Ideally, it'd be preceded by numerous robotic probes that'd chart the worlds ahead for possible refueling stops (that could add a couple thousand years to the mission) and have a number of possible targets lined up on a reasonable trajectory so that if the next system is not really that hospitable or doesn't have anything worth doing a very large delta-v for, it can just press ahead to the next destination. Another thing it'd need is a lot of determination to build it, to seal it with a population, test it for generations to make sure the ecosystem works and is stable, and then send it out into the unknown without any possibility of returning to Earth. It's very long term engineering we rarely do.
valuearb 5y ago
There are numerous credible designs for space ships able to reach a few percentage points of the speed of light. Reaching 10% would be enough to visit nearby stars within a lifetime. And once we can extend human life spans to many hundreds of years these journeys become even more achievable.
- OmicronCeti 5y ago
  >credible designs As I said elsewhere, I think the disconnect here is between potential and probable. Homo sapiens have twice come to the edge of nuclear oblivion already (being saved only by luck essentially), and I would wager we are are speeding much faster towards nuking each other than reaching the stars.

dheera 5y ago

Planes work quite differently from birds. We were inspired by them, but we didn't copy them at all. Attempts in the past to copy birds mostly failed. We got to the moon, Mars, and several other solar system bodies in the past half century without any mimicry. Maybe you don't, but I have very strong optimism for technological advancement, and also for modifying our life form to rid ourselves of our tendency to destroy things before heading to other stars. When I say "we" will go to other stars, it won't be Homo sapiens, but another species that we will create as our successor.

OmicronCeti 5y ago
The distance to the moon and Mars is absolutely trivial compared to even the closest star: to Mars is 0.0007% of the way to Alpha Centauri. >We got to the moon, Mars, and several other solar system bodies You're conflating humans and probes, which are vastly different.
- dheera 5y ago
  > You're conflating humans and probes, which are vastly different. I disagree. Robots can build infrastructure far ahead of human settlement, such that everything already exists when we are ready to travel. We can also potentially re-engineer our own life form, or create an entirely new inorganic lifeform, to withstand various conditions, including radiation and a wider range of temperatures. That will be our successor. We are only beginning to understand genetics in the past decade. We have a long, long way to go, and a lot to understand. Science is still at its infancy. Also, this is something I could never say in an academic context, but deep down I don't believe in conservation of energy, partly because the big bang itself violates it. Yes, I would be ridiculed for saying this in a scientific context, but so would someone in the 1500s for saying that the Earth goes around the sun. I think at some point in the distant future we will not be reliant on stars as our energy source.
  - OmicronCeti 5y ago
    'we' did not go to Mars, 'we' did not go to pluto. We sent cameras with walky-talkies. That is so vastly different than sending people to the moon, that it's not really something we can disagree on in good faith. If you truly do not believe in the conservation of energy, I think we're done here since none of my arguments will be good enough for such wild speculation.
    - dheera 5y ago
      If we can send cameras with walky-talkies, we can invent and send (possibly silicon-based) life forms that will carry on our legacy while being a lot more resistant to the elements, require much less support along the journey, and can tolerate whatever gases and radiation may be present at the destination while still reproducing and carrying on society just as life does now. Human bodies suck because they need to eat, need to poop, complain if what they eat isn't tasty, fight with each other, and get cancer, but our legacy as intelligent life doesn't need to continue in our current carbon-based meat bag form.
      - OmicronCeti 5y ago
        I can't believe I'm entertaining a reply, but how would a human-invented lifeform sent to the stars carry on human society if it is a) not human, and b) light years spatially distance and thousands of years temporally distant? This reads like an ungrad astronomy major fever dream.
        dheera 5y ago
        It would carry on our legacy as intelligent life. I don't think maintaining our current iteration in evolution is a condition that should be valued. We can evolve, or invent another life form that carries our civilization forward. Yes, it reads like a dream. Technological breakthroughs of the past were created by people with dreams, not by skeptics.
        natch 5y ago
        The question “what makes us human” is a deep one that has vexed philosophers for a long time. I don’t have the answer. If you have the answer, forgive me if I take it with a grain of salt. I do think it’s possible that our best hope for navigating the transition beyond the singularity involves transplanting our humanness to another kind of life form. I’m not necessarily talking about uploading… more about a staggered intergenerational transition mixed in with life as we know it. I realize that to some people, this will continue to sound like crazy talk, until one day it isn’t. It’s ok if you are one of those people :-).
- valuearb 5y ago
  We didn’t land on the moon?
- lmm 5y ago
  LEO is 0.0005% of the way to the Moon, and yet once we'd done the first it didn't take us long to scale up to the second.
  - OmicronCeti 5y ago
    That's simply a facile comparison because most of the fuel is needed to get out of the atmosphere. The energy required for that 0.0005% distance is nearly 66% of the total. Let's say it takes ~8 minutes to get to LEO vs 4,380 minutes to get to the Moon. That's a factor of ~550x longer flight time for a distance 2000x further. Alpha Centauri is 1500x further away than Mars. It currently takes ~7 months to go from Earth to Mars (at 25,000 mph), assuming similar scaling that comes out to only 400x the flight time, or just about 230 years.
throwawayboise 5y ago
We got to the moon. 12 humans have walked on it. Note that 50 years later, nobody is living there, or working there. Nobody has even returned. We may get humans to Mars. It's technically possible. But I don't think we will ever live there.
- dheera 5y ago
  50 years isn't a long time. I'm sure some dude said the same thing about Tibet being too harsh to live in, and yet there are cities there now.
  - OmicronCeti 5y ago
    What are you talking about? People have lived in Tibet for 20,000+ years?
- OmicronCeti 5y ago
  The person you're replying to stated elsewhere that they don't believe in the conservation of energy, so (ironically) save yourself the energy of arguing with them.
  - chub500 5y ago
    Not to detract from your sarcasm but the conservation of energy only holds true in flat spacetime. So I guess you don't 'believe' in curved spacetime? That makes you a flat spacetimer I guess...

kortilla 5y ago

The breakthroughs in flying came when we stopped trying to make machines look like birds. Submarines work well because we didn’t bother making them anything like fish.

rbanffy 5y ago

> There is no model for instellar transit. There is, but extrasolar objects don't have engines and do very low energy transits. We'd need a large habitat, a power source that can last for a couple thousand years and a lot - and I mean a LOT - of reaction mass to accelerate it and to brake it when it arrives at its destination. Ideally, it'd be preceded by numerous robotic probes that'd chart the worlds ahead for possible refueling stops (that could add a couple thousand years to the mission) and have a number of possible targets lined up on a reasonable trajectory so that if the next system is not really that hospitable or doesn't have anything worth doing a very large delta-v for, it can just press ahead to the next destination. Another thing it'd need is a lot of determination to build it, to seal it with a population, test it for generations to make sure the ecosystem works and is stable, and then send it out into the unknown without any possibility of returning to Earth. It's very long term engineering we rarely do.

valuearb 5y ago

There are numerous credible designs for space ships able to reach a few percentage points of the speed of light. Reaching 10% would be enough to visit nearby stars within a lifetime. And once we can extend human life spans to many hundreds of years these journeys become even more achievable.

OmicronCeti 5y ago
>credible designs As I said elsewhere, I think the disconnect here is between potential and probable. Homo sapiens have twice come to the edge of nuclear oblivion already (being saved only by luck essentially), and I would wager we are are speeding much faster towards nuking each other than reaching the stars.