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Matrioshka Brains: computing at the limits of physics

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Re: Matrioshka Brains: computing at the limits of physics

#21

Post by mnemonicsloth »

akkartik wrote: post #12

Hey Zyvex, it's 2010. How's my diamondoid nanoassembly coming along?

Drexler Sayeth:

Contrary to popular opinion, diamond synthesis seems almost irrelevant to progress toward advanced nanosystems. At the current stage or research, it is both difficult and unnecessary.

The current view is that we're ready to start work on a first generation of nanoassembly tools using designed proteins for tooltips and DNA scaffolds for programmable, atomically precise structure. The trouble is that it doesn't look like a first generation of molecular manufacturing tools are just around the corner, so the research isn't getting done.

http://metamodern.com/2008/12/27/toward-advanced-nanosystems...

Re: Matrioshka Brains: computing at the limits of physics

#22

Post by khafra »

cstross wrote: post #17
varjag wrote: post #4

One would imagine that on a Dyson sphere sized computer, intercommunication (limited by speed of light) will become major bottleneck. At some point amassing components will stop winning you performance due to physical dimensions.

Yes, lightspeed is a bottleneck. A particular problem is that the computing elements are presumably vulnerable to radiation damage, thus placing a lower limit on the internal radius of the MB's innermost shell. If MBs are migratory, that's a good reason for expecting them to be associated with cooler, dimmer red dwarf stars -- or to be concentrated some way away from their stellar energy source, leaving a classical D…

I found your exposition on the other limit--bandwidth outside the brain--even more interesting. Assuming life expands to fill the available resources, once you create a Matrioshka brain you're pretty irrevocably tied to your star, for good or for ill.

Re: Matrioshka Brains: computing at the limits of physics

#24

Post by chromophore »

drunkpotato wrote: post #8
chromophore wrote: post #3

http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_s... The link above is to a fermi lab program to look for Dyson spheres. The Matrioshka brain is a subset of the Dyson sphere. Something made famous, unfortunately, by Trekkers.

Why is that unfortunate?

Unfortunate because it has distorted the original idea beyond recognition. :) A lot of people know F. J. Dyson only for Dyson "spheres" (the original conception was that of a swarm, SF modified the idea to a sphere, then shell). Though it's obvious he did a lot of other work and that the Dyson sphere was nothing as compared to what he has done. It was just a thought experiment.

Re: Matrioshka Brains: computing at the limits of physics

#25

Post by apsurd »

cstross wrote: post #2

I'd like to note that this is probably the biggest borderline-plausible hard SF idea not to have caught on (at least on a large scale) in genre fiction. And that I shamelessly strip-mined Mr Bradbury's mountain of ideas for props in "Accelerando". (In case you were wondering where SF writers get their ideas from ...)

http://www.antipope.org/charlie/blog-static/2009/03/reminder...

Respect.

Re: Matrioshka Brains: computing at the limits of physics

#27

Post by Confusion »

varjag wrote: post #4

One would imagine that on a Dyson sphere sized computer, intercommunication (limited by speed of light) will become major bottleneck. At some point amassing components will stop winning you performance due to physical dimensions.

I think that limitation would become a major bottleneck long before you reach Dyson sphere size. Internode communication is already the major bottleneck for modern supercomputers, which limits the possibly achievable computational speed for every problem except for strictly parallellizable problems that do not require such internode communication.

Re: Matrioshka Brains: computing at the limits of physics

#28

Post by eru »

Alex3917 wrote: post #19
cstross wrote: post #2

I'd like to note that this is probably the biggest borderline-plausible hard SF idea not to have caught on (at least on a large scale) in genre fiction. And that I shamelessly strip-mined Mr Bradbury's mountain of ideas for props in "Accelerando". (In case you were wondering where SF writers get their ideas from ...)

Probably because it's so improbable. It essentially assumes that we'll hit the limits of technological innovation without discovering that any of our current ideas about physics and the nature of the universe are completely wrong. Long before we could ever make such a device I suspect we'll discover something along the lines of zero-point energy being real harvestable, that the universe is not in fact material and lo…

The universe is in fact not 'material' in some senses of the word. We already know that information / entropy is as least as real as energy and matter. And there are some hints that they may be even more fundamental.

Re: Matrioshka Brains: computing at the limits of physics

#29

Post by eru »

khafra wrote: post #22
cstross wrote: post #17

Earlier quoted context omitted.

Yes, lightspeed is a bottleneck. A particular problem is that the computing elements are presumably vulnerable to radiation damage, thus placing a lower limit on the internal radius of the MB's innermost shell. If MBs are migratory, that's a good reason for expecting them to be associated with cooler, dimmer red dwarf stars -- or to be concentrated some way away from their stellar energy source, leaving a classical D…

I found your exposition on the other limit--bandwidth outside the brain--even more interesting. Assuming life expands to fill the available resources, once you create a Matrioshka brain you're pretty irrevocably tied to your star, for good or for ill.

You might still want to send out `seeds' to other stars. Even if you can't communicate with them fully.

Re: Matrioshka Brains: computing at the limits of physics

#30

Post by elblanco »

cstross wrote: post #2

I'd like to note that this is probably the biggest borderline-plausible hard SF idea not to have caught on (at least on a large scale) in genre fiction. And that I shamelessly strip-mined Mr Bradbury's mountain of ideas for props in "Accelerando". (In case you were wondering where SF writers get their ideas from ...)

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