[glomgril]

Very cool. Got a silly sci-fi question for you. IIUC, with current technology it would take on the order of tens of thousands of years for a vessel to physically travel to the closest known Earth-like planet (correct me if I'm wrong).

So any thoughts on what kinds of hypothetical breakthroughs would be needed to make the trip doable in (say) less than a human lifetime?

And related, what do you think about the plausibility of the [Breakthrough Starshot](https://en.wikipedia.org/wiki/Breakthrough_Starshot) initiative? Aware of any alternative approaches?

[idlewords]

A different stab at this is to ask what it would take to build a telescope that could image some of these Earth-like planets, a project that turns out to be easier (in a very loose sense of that word) than sending cameras there.

The idea is you send a camera very, very far out in the Solar System (hundreds of AU) and then use the Sun's gravity well as your lens. Neat stuff and, unlike the interstellar probes, potentially doable in our lifetime.

https://en.wikipedia.org/wiki/Solar_gravitational_lens

[rocqua]

Normally, diffraction and the effective aperture are what limit optical resolution. How does that work with gravitational lensing? Does the effective aperture become the diameter of the sun?

[stevenwoo]

Self replicating automata as described by Von Neumann able to repair and duplicate themselves, and other things like electronic components. ICs keep getting faster (so far) but use smaller and smaller features of silicon and could wear out from metal migration and all components will be under much more cosmic radiation than on earth. This makes a large shield of heavy material on front of vehicle to minimize this effect but that increases the energy/fuel needed. The space shuttle only took maybe week long trips but it had four computers for flight control , three extra in case of failure in different parts of the shuttle along with IIRC a separate backup backup computer in for use as last resort.

[nine_k]

* Research faster interstellar travel, especially using something like a Buzzard engine to utilize interstellar hydrogen as resection mass. Required nuclear fusion power plants / engines and ridiculously strong magnetic fields; both seem attainable.

* Slow down human body metabolism and allow humans to stay asleep at near-freezing temperatures for a long time. If bears and chipmunks can do it, chances are humans could learn it, too.

* Invent sets of machines that can reliably self-replicate, given most basic inputs like minerals, water, and sunlight. Advanced semiconductors are going to be the tricky part.

* Study psychology, sociology, history, game theory, etc, so that the early society that will form on the new planet, isolated from Earth, would avoid at least some of the pitfalls that plagued human history on its home planet.

[ben_w]

> Buzzard

That's a bird, the engine is named after a person and is spelled differently:

https://en.wikipedia.org/wiki/Bussard_ramjet

Also, it won't work unless scaled up to the sort of thing only a Kardashev type II could do — 4000 km diameter — and at that level you've got other options that mean they probably won't:

https://arstechnica.com/science/2022/01/study-1960-ramjet-de...

[konart]

>Slow down human body metabolism and allow humans to stay asleep at near-freezing temperatures for a long time. If bears and chipmunks can do it, chances are humans could learn it, too.

The thing is - our current bodies can't live in space for long. So either we will have to build new bodies for us somehow or build a ship that can have gravity inside and protection from space outside (and we are talking about very heavy protection here)

In any other case there is no point in slowing down metabolism or whatever. You will die rather soon.

[BugsJustFindMe]

Time dilation means that the closer you get to the speed of light the less time you experience passing. So even a 12000 year long journey as seen from earth, if moving fast enough, could feel to the travelers like a much shorter amount of time.

[stevenwoo]

Yes, but practically with todays technology there is no feasible way of getting to a speed where time dilation matters over that distance, we run out of fuel so we need some external power source like a laser or solar wind that have other issues, iirc one only gets to 2x time dilation at 0.9 c. That’s a lot of acceleration.

[galangalalgol]

And we don't have to send people, we should do our job as a Von Neumann probe and send frozen rna to distribute across the surface.

[dustingetz]

and in that 10,000 year blink, a civilization progresses from bronze metalworking to digital computers, awaiting our arrival

[AtlasBarfed]

Can't pulse nuclear get there? Or does it require antimatter catalyzed fission?