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A metallurgist's doubts about self-replicating probes

centauri-dreams.org

11–20 of 103 posts

Re: A metallurgist's doubts about self-replicating probes

#11

One "solution" to these problems is to have the probes land on planets instead of asteroids, and build the necessary infrastructure there.

That solves many of those problems, although it rather introduces a big gravity well to escape from when replication is complete.

Re: A metallurgist's doubts about self-replicating probes

#12

Wouldn't a counter this argument be biological systems? These are reasonable points as long as we are talking about current methods, but I assume if we were to get to the point of self replicating probes it would be done by something like nanotechnology, synthetic biology like systems.

We are selfreplicating bots - can eat anything, self healing minor damage, very agile, autonomous. When we stop growing numbers the harvest will begin

Re: A metallurgist's doubts about self-replicating probes

#13

> Shrinking that into a 500 kg seed — or even Freitas’ original 100-ton seed — is not an engineering detail. It may be the entire problem. How many AI tells can you count there? But honestly (see what I did there?) the AI slop is reasonably cleaned up in this piece. However, the essence of the argument has two deep flaws. One is that the time to complete an interstellar voyage is extremely long and you need some exer…

300 years ago people also believed alchemy was a serious field of study

That is true. What should we conclude from this statement?

Re: A metallurgist's doubts about self-replicating probes

#14

Wouldn't a counter this argument be biological systems? These are reasonable points as long as we are talking about current methods, but I assume if we were to get to the point of self replicating probes it would be done by something like nanotechnology, synthetic biology like systems.

We are selfreplicating bots - can eat anything, self healing minor damage, very agile, autonomous. When we stop growing numbers the harvest will begin

thats what i meant.

Re: A metallurgist's doubts about self-replicating probes

#15
I did some research on this in the context of self-replicating PV panel construction. I arrived at similar conclusions: mining (ore extraction and refining) was the hardest part. Our current methods involve all involve some kind of high energy system:

- crushing

- breaking down with powerful solutions

- blasting

And a self-replicating probe will (initially at least) be a low energy system. I eventually decided that the pathway with the most likelihood of success would be some kind of very slow crushing/grinding machine that can break down ore into separable components, but then you get into a kind of Darwinist explosive combinatorics research rabbit hole: which crusher/grinder, what kind of machine, how to make something that works on different ore types, what mechanical pressure is better?

Conceptualizing something that can sinter and assemble PV cells was pretty easy, there are broad families of chemistries that work and they mainly differ on input temperatures and output efficiencies. Fairly tractable. But mineral extraction... yeesh, it's extremely difficult.

FWIW on the original article: I think the jump from "insulating wires" to "semiconductor fabs" was kind of obtuse. You don't necessarily need Turing complete PCBs or microchips for most (any?) of this.

Re: A metallurgist's doubts about self-replicating probes

#16

Wouldn't a counter this argument be biological systems? These are reasonable points as long as we are talking about current methods, but I assume if we were to get to the point of self replicating probes it would be done by something like nanotechnology, synthetic biology like systems.

We are selfreplicating bots - can eat anything, self healing minor damage, very agile, autonomous. When we stop growing numbers the harvest will begin

> When we stop growing numbers the harvest will begin

I like this part. It gives me chills.

Re: A metallurgist's doubts about self-replicating probes

#17

Earlier quoted context omitted.

We are selfreplicating bots - can eat anything, self healing minor damage, very agile, autonomous. When we stop growing numbers the harvest will begin

thats what i meant.

... but traveling for months, years, decades and millennia in space away from earth has proven difficult so far. Even astronauts in space for a year had significant changes afterwards.

Re: A metallurgist's doubts about self-replicating probes

#19

Wouldn't a counter this argument be biological systems? These are reasonable points as long as we are talking about current methods, but I assume if we were to get to the point of self replicating probes it would be done by something like nanotechnology, synthetic biology like systems.

Somewhat famously with life, you aren't necessarily replicating the same thing at the end as you are at the beginning, which is an awkward property for an engineered system.

Re: A metallurgist's doubts about self-replicating probes

#20
post #5

There is no doubt that compressing a whole industrial supply network into a little probe is incredibly hard. But I can't see microgravity specifically as a huge challenge. If you can get a probe to another star system, you can probably figure out how to spin it.

I suppose it depends if you're assuming the probe is a complete factory, just taking in regolith and spitting out new probes, vs if the probe deploys and builds up the factory on the surface of an asteroid.

In the latter case spinning doesn't get you far.

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