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Interstellar Flight: Perspectives and Patience

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Re: Interstellar Flight: Perspectives and Patience

#121

Post by nosianu »

Matumio wrote: post #117
jillesvangurp wrote: post #114

Earlier quoted context omitted.

Worse, you have no idea what you will find on the other side and weather that includes somewhere that doesn't make the arctic poles on earth look like paradise. And you'll be traveling in a small confined space. For ages. The good news is, you'll probably be unconscious for the journey. The bad news is that a lot can happen in decades/centuries/milennia and there's no guarantee you'll actually wake up. And everything…

Given those time frames, maybe don't send primates. Send a computer babysitting a diverse zoo of bacteria and algae, with a variety of landing devices and instructions in what order to deploy them under which circumstances. Same problem: the best-case outcome is that we never hear anything interesting from that rocket ever again. But it should be a lot cheaper.

> Send a computer

Those age too. Especially out there without the earth's shields. If you make one that lives longer than a human it's already quite the feat, add only a bit more radiation, it only gets worse. Computers are much worse with failures than brains too.

The nice thing about biological systems is the self-assembly from tiny molecule parts. Worst case, you can create a closed system with birth/death renewal. For tech the machines that build the machines, and the machines that build or repair those in turn, will all have to be brought along too, or you need to have some impossibly tough requirements for the product to last.

We may need some similar automatic self-assembly for tech for such use cases. The whole spaceship and all its components will deteriorate too.

Even when we sent out ships to venture around the world they had to be able to do replacements for broken parts, like masts. We probably need that capability for space ships too, to stop at some asteroid and rebuild. But then you get the equivalent of the rocket equation: On the one hand, you need a lot of stuff to support that manufacturing, on the other hand, every item you add itself needs maintenance and rebuilding at some point. The way out is this molecular-level self-assembly. You throw a few tiny nano-machinery dust spores on an asteroid, and ten years later you grew some useful machinery...

Re: Interstellar Flight: Perspectives and Patience

#122

Post by kfuse »

Why is everyone so fixed on interstellar travel? What if the galaxy is chock full of rogue planets? There may be hundreds if not thousands of worlds between us and the surrounding stars. Hopefully, Roman Telescope set to launch in 2027 is going to find lots of them.

Re: Interstellar Flight: Perspectives and Patience

#123

Post by baxtr »

kfuse wrote: post #122

Why is everyone so fixed on interstellar travel? What if the galaxy is chock full of rogue planets? There may be hundreds if not thousands of worlds between us and the surrounding stars. Hopefully, Roman Telescope set to launch in 2027 is going to find lots of them.

Because we’re a species of explorers. At least some of us are.

Re: Interstellar Flight: Perspectives and Patience

#124

Post by baxtr »

imoreno wrote: post #109

With Alpha Centauri being only 4 light years away, interstellar travel seems almost feasible. But then you consider all the inconvenient details, and realize such a journey would have to take hundreds, maybe thousands or even more years on top of some incredible advances in rocket tech. If you go to something like Trappist (40 ly) at 0.01c (very optimistic), it's not just that everyone you know will be dead when you…

Maybe not humans, what about robots though?

I recently read this in an interview with Juergen Schmidhuber:

> Of course, such life-like hardware won't be confined to our little biosphere. No, variants of it will soon exist on other planets, or between planets, e.g. in the asteroid belt. As I have said many times in recent decades, space is hostile to humans but friendly to suitably designed robots, and it offers many more resources than our thin layer of biosphere, which receives less than a billionth of the energy of the Sun. Through life-like, self-replicating, self-maintaining hardware, the economy of our solar system will become billions of times larger than the current tiny economy of our biosphere. And of course, the coming expansion of the AI sphere won’t be limited to our tiny solar system.

https://news.ycombinator.com/item?id=44330850

Re: Interstellar Flight: Perspectives and Patience

#125

Post by soco »

baxtr wrote: post #124
imoreno wrote: post #109

With Alpha Centauri being only 4 light years away, interstellar travel seems almost feasible. But then you consider all the inconvenient details, and realize such a journey would have to take hundreds, maybe thousands or even more years on top of some incredible advances in rocket tech. If you go to something like Trappist (40 ly) at 0.01c (very optimistic), it's not just that everyone you know will be dead when you…

Maybe not humans, what about robots though? I recently read this in an interview with Juergen Schmidhuber: > Of course, such life-like hardware won't be confined to our little biosphere. No, variants of it will soon exist on other planets, or between planets, e.g. in the asteroid belt. As I have said many times in recent decades, space is hostile to humans but friendly to suitably designed robots, and it offers many…

But why would we bankrupt ourselves sending those robots at all? Although, if AI takes over in a way or another, who knows what they recommend/decide.

Re: Interstellar Flight: Perspectives and Patience

#126

Post by tenthirtyam »

sorcerer-mar wrote: post #92
pfdietz wrote: post #90

Earlier quoted context omitted.

And the delta-V back from a NEO is as little as 1% of that to get to LEO from the Earth's surface. Also, the materials we're talking about from asteroid mining, like platinum group elements, probably are shipped by air, just for security. This whole argument is reminding me of the facile and bogus argument that launch to earth orbit from planet's surface is expensive because of the energy needed.

If it's a bogus argument then mount a counterargument. The question is simple: what is worth mining in space? So far we have... "maybe platinum." Maybe! Aside from the conspicuous absence of math, "maybe platinum" isn't remotely important enough a factor in earthbound mining to justify asteroid mining on the basis of preserving earth, obviously.

I recently read "Delta-v" and the sequel "Critical Mass: A Novel" by Daniel Suarez. They're very much fiction but there is a certain amount of science underpinning the arguments and I enjoyed that aspect. And the author even states that he's trying to get across, with solid arguments, why humanity should begin planning asteroid mining ASAP. In brief, the arguments are:

Firstly we're now at a point where we have lots of cheap energy available, principally chemical. Depending on many factors it's conceivable that we are in fact at or near peak human energy output (e.g. WW3 or civilization collapse - the next iteration of civilization won't have so much cheap oil to exploit).

Secondly LEO is not yet full of junk, meaning that it's trivial to find launch windows to LEO and beyond. That could easily change very much for the worse in a relatively short time (I infer decades from the books).

Finally it's unrealistic to expect us to colonize the Moon or Mars using only Earth-mined materials. You can launch a spacecraft to Mars easily, but to launch a small city's amount of construction equipment and raw materials is beyond our capabilities.

Conclusion: now is the best time to mine asteroids. We can do all of the processing and much of the construction in LEO (or even better at Earth-Moon or Earth-Sun lagrange points) and then, with relatively low delta-v, we'd actually have a chance of becoming an interplanetary species!

But, the novels warn, the window of opportunity will eventually ("soon") close. Well worth the read.

Maybe someone else more familiar with the arguments, who has also read these novels, can offer a critique?

Re: Interstellar Flight: Perspectives and Patience

#127

Post by baxtr »

soco wrote: post #125
baxtr wrote: post #124

Earlier quoted context omitted.

Maybe not humans, what about robots though? I recently read this in an interview with Juergen Schmidhuber: > Of course, such life-like hardware won't be confined to our little biosphere. No, variants of it will soon exist on other planets, or between planets, e.g. in the asteroid belt. As I have said many times in recent decades, space is hostile to humans but friendly to suitably designed robots, and it offers many…

But why would we bankrupt ourselves sending those robots at all? Although, if AI takes over in a way or another, who knows what they recommend/decide.

I’m sure if you ask ChatGPT often enough it’ll recommend exactly that!

Re: Interstellar Flight: Perspectives and Patience

#128

Post by tenthirtyam »

jmyeet wrote: post #84

So this is another reason why I see Dyson Swarms as being the inevitable evolution of human civilization. Let me explain why. First, to clarify, a Dyson Swarm is a cloud of orbitals around a star to use most or all of its energy via solar collectors. This was originally called a Dyson Sphere but was renamed because of confusion: people thought a Dyson Swarm was a rigid shell. It never was. Anyway, the classic orbital…

Like "Rendezvous with Rama" by Arthur C Clarke: A mysterious cylindrical spaceship arrives at planet Earth from outer space.

Re: Interstellar Flight: Perspectives and Patience

#129

Post by thechao »

pfdietz wrote: post #75
d_silin wrote: post #32

Developing propulsion technology to reach 0.1c velocity will move the needle on interstellar propulsion from impossible to just barely feasible. Although that is at least 100-200 years away, we can absolutely start expanding into our Solar System, starting with nearby bodies, like Moon and Mars.

However, travel at 0.1c is not needed for the Fermi Argument to bite. Much slower speeds would allow a colonization wave to sweep a galaxy in time << the age of the universe.

Even at .0006c (our current tech), the galaxy would be filled with (weakly self propagating) robotic probes after just 750 million years. Unless extremely long lived self-propagating probes just ... die out ... that implies no aliens older than 750 million years from our galaxy. It implies no aliens from the nearby galactic neighborhood within 3 billion years. That kind of implies we're all alone.

I have three wild-eyed theories: (1) eukaryotism is an unbelievably exotic step; (2) and/or the moon is required and ultrarare; or, (3) advanced civilizations eschew yellow stars for being inconveniently short-lived: maybe they prefer brown dwarfs, white dwarfs, or black holes for their energy gradient.

Re: Interstellar Flight: Perspectives and Patience

#130

Post by xpuente »

adrian_b wrote: post #113
xpuente wrote: post #112

It won’t be us. It will be our descendants — the machines.

Any autonomous machines in a distant enough future will look neither as the present humans or animals nor like the present robots, because they will have to use a mixture of the technologies developed by living beings and by humans. Humans have developed various things that are better for certain purposes than anything used by a living being, e.g. metals and semiconductor devices (most of the human-only technologies…

Consciousness, once engineered, will make any biology redundant.
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