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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> extropy-chat-bounces@lists.extropy.org [mailto:extropy-chat-bounces@lists.extropy.org] <b>On Behalf Of </b>Adrian Tymes<br><b>Sent:</b> Wednesday, August 28, 2013 10:51 AM<br><b>To:</b> ExI chat list<br><b>Subject:</b> Re: [ExI] Silence in the sky-but why?<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p>On Aug 28, 2013 10:31 AM, "BillK" <<a href="mailto:pharos@gmail.com">pharos@gmail.com</a>> wrote:<br>><span style='color:#1F497D'>>…</span> Considering the size of the universe, galaxies without number as far<br>> as we can see, it seems unbelievably arrogant to say that humans are<br>> the only intelligent life.<span style='color:#1F497D'> BillK</span><o:p></o:p></p><p><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I am OK with arrogance. It is one of my favorite emotions. But it really isn’t so much arrogance as I just can’t convince myself it is so, even though it does explain the silence in the sky. I have set one of the Hubble deep sky images as my background screen. Every time I close all my windows, I am gazing out into vast stretches of space, shimmering with unimaginably numerous billions of galaxies. And I think: all those stars, so small, far away and insignificant, and here I am right down here in the middle of all this, so big and strong.<o:p></o:p></span></p><p><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Well, I don’t really think that, but it tickles my arrogant side. Actually what I think is how the hell could we be the first or the only?<o:p></o:p></span></p><p><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>But let me try an argument on you please BillK.<o:p></o:p></span></p><p><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>At some point somewhere in time, some intelligent life form was the very first. We can set aside for now the argument that this first wise guy is us, and agree that somewhere and somewhen in the observable universe, someone was first. If we assume, quite reasonably, that this first intelligent tech-enabled species wanted to colonize the universe or at least the galaxy it inhabited, I proposed years ago a design for an MBrain node, that looks like this:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Sun side: Away from sun side:</span><!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f">
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</v:shape><![endif]--><![if !vml]><span style='mso-ignore:vglayout;position:absolute;z-index:251663360;margin-left:21px;margin-top:53px;width:435px;height:429px'><img width=435 height=429 src="cid:image004.png@01CEA43F.F70AAD10" v:shapes="_x0000_s1026"></span><![endif]><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='color:#1F497D'>The reason I wanted to start with the assumption of the first intelligent species is that that particular species would definitely see a radio silent sky, and all the signals it sent out would go forever into cold dark dead space. So if that species wanted to spread, it would need to move actual matter, atoms and molecules, rather than instructions on how to build copies of itself. So, these nodes would need to go.<o:p></o:p></span></p><p><span style='color:#1F497D'>There is a good reason to think interstellar space could have diffuse hydrogen clouds that would be mission-enders if you encounter one, even at .001c. Your spacecraft would ablate away. But if you took your entire star along, then the radiation from that star would dissipate the hydrogen, as our star does now.<o:p></o:p></span></p><p><span style='color:#1F497D'>Approximate dimensions about 120 mm diameter, so it is about the size of our DVDs for those of you who are old enough to remember those, and with three LCD regions for maintaining a desired attitude towards the first smart star, I showed that a sufficiently large swarm of these things could move a star anywhere you wanted to go.<o:p></o:p></span></p><p><span style='color:#1F497D'>My realization today is that with an MBrain moving a star, it could go to a binary where both stars in the binary are on the main sequence. For main sequence stars, the luminosity increases as 2^3.5 times the mass. So doubling the mass would increase the luminosity by a factor of about 10, and this would increase the available acceleration by 10. So the trick is to move the home star to the nearest star and collide them, assuming their combined mass is below the limit so that the combined stars would not go supernova, then speed off at an acceleration of 10 times as many nanometers per second squared, or if you don’t mind the oddball unit, several tens of meters per square year.<o:p></o:p></span></p><p><span style='color:#1F497D'>Oy vey, I realized that this whole post is babbling, and assumes everyone who reads this far was in on the discussing going back at least ten years.<o:p></o:p></span></p><p><span style='color:#1F497D'>I need to go back and write some introduction to moving stars with MBrains. Does everyone here know what I mean by that? You reflect some fraction of the star’s radiant energy in one direction, and since momentum is conserved, the whole star and planet system goes the opposite direction the MBrain aims the light. Today’s realization: you combine stars to make them faster. The first smart species would eventually invent an MBrain and start rocketing away to the nearest star. Wouldn’t it?<o:p></o:p></span></p><p><span style='color:#1F497D'>spike<o:p></o:p></span></p><p><span style='color:#1F497D'><o:p> </o:p></span></p><p><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p></div></body></html>