[ExI] mbrains again: request

Eugen Leitl eugen at leitl.org
Wed Sep 28 13:06:24 UTC 2011

On Wed, Sep 28, 2011 at 10:48:28AM +0100, Anders Sandberg wrote:
> spike wrote:
>> Here’s the discovery. As far back as ten years ago, I was fooling with  
>> MBrain orbit calculations and discovered that an MBrain can move an  
>> entire star. This past weekend, I was using the same equations I  
>> derived back then and discovered the original comment was an  
>> understatement. Not only can an MBrain move a star, it must move a  
>> star. Above a certain total area covered by MBrain MNeurons, if the  
>> MBrain does not exhaust a certain percentage of the star’s light on  
>> the first reflection, the swarm cannot reach thermal equilibrium and  
>> maintain temperatures within the solid phase range of known materials.
> Just absorbing and re-radiating the luminosity as blackbodies produces a  
> nice equilibrium temperature as far as I can see - the star's envelope  
> gets a tiny fraction hotter, but nothing else. I need some extra hint  
> here: has this to do with the orbiting of the MNeurons?

You need to use photon momentum (no need to waste mass) for active node
orbit control, as otherwise the node cloud orbits will degenerate and you'll 
get internode collisions, which can cause a runaway collision catastrophe 
by way of fragments and turn your node cloud into a dusty fragment cloud.

On the average total, the control flares should result in an isotropic 
radiation pattern, though. 

Is it even possible to push the entire assembly by emitting radiation 
mostly in one direction, climbing up in a higher orbit half the time, 
and descending down the other half?

It's probably analytically too hard, so somebody could model it.

Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org
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