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Interstellar Flight: Perspectives and Patience

(www.centauri-dreams.org)
92 points JPLeRouzic | 2 comments | 25 Jun 25 16:35 UTC | HN request time: 0.645s | source
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imoreno ◴[26 Jun 25 06:28 UTC] No.44384709[source]▶
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 arrive. Your entire nation will have disappeared to the sands of time. The landfall announcement you send back will be incomprehensible because of language shifts, and you won't live to see the reply. Meanwhile, such a trip would be an enormous investment, requiring multiple nations to bankrupt themselves, with no hope of even surviving to see the outcome.

With that, it's very hard to imagine interstellar travel being feasible with our current understanding. There would have to be something like FTL travel or wormhole. The only "realistic" development, (much) better engines that can do 0.1c, would not actually change much.

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jillesvangurp ◴[26 Jun 25 08:07 UTC] No.44385252[source]▶
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 else you said.

That raises the question who would want to travel and why. And what's wrong with them. Because the profile for people that want this would be hard to distinguish from somebody that is depressed and suicidal.

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1. Matumio ◴[26 Jun 25 08:45 UTC] No.44385458[source]▶
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.

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2. nosianu ◴[26 Jun 25 09:44 UTC] No.44385740[source]▶
> 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...