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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>From:</b> extropy-chat <extropy-chat-bounces@lists.extropy.org> <b>On Behalf Of </b>John Clark<br><b>Subject:</b> Re: [ExI] Tabby's star, computronium size<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'>On Sun, Mar 25, 2018 at 5:34 PM, Keith Henson <<a href="mailto:hkeithhenson@gmail.com" target="_blank">hkeithhenson@gmail.com</a>> wrote:<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div><div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><p class=MsoNormal><i><span style='font-family:"Arial",sans-serif'>>> Tabby's star is taking another dip and it would be interesting to measure the size and consistency of the dust. Dust dims blue light more than red light.</span></i><span style='font-family:"Arial",sans-serif'><o:p></o:p></span></p></blockquote><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>>… the dust particles are larger than 10^-6 meters and smaller than 2*10^-3 meters. That's pretty small, I can't see any reason a ET engineer would make a computronium node that small…<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>Indeed sir? If they are up in the 1 – 2 mm range I would be puzzled about why they are so big. For a lotta thermodynamic reasons, about .1 mm is right in the zone for computronium. In that range, your surface area to volume ratio is good for collecting sufficient energy from the star while still being able to reject heat passively (the jury is still out on the thermodynamic considerations after all this time.)<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>>…And how does the computronium theory explain the observations better than the dust theory does?<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>The dust notion depends on whatever caused the dust to have been a very recent event. Otherwise the cloud would be more uniform than they are, ja? It is possible of course that we are seeing the aftermath of something that happened within the last few tens of thousands of years. But computronium will be as clumpy as is practical.<o:p></o:p></span></p><p class=gmail-p2><o:p> </o:p></p><p class=gmail-p2>>…<span style='font-size:13.5pt;font-family:"Arial",sans-serif'>Are Saturn's rings made of computronium too?<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>Not yet. Working that.<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>>…Even Tabetha Boyajian after whom Tabby's Star is named thinks its just dust, probably because she believes in Occam's razor…<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>Sure but what if… we discovered a portrait of William of Ockham and… he had a huge shaggy beard? Would she still believe in it?<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>John we recognize there is plenty of wishful thinking orbiting Tabby’s star. If it fires our collective imagination and gets smart ambitious grad students to get with it on their calcs of what a computronium cloud would look like, perhaps this will eventually result in a computronium cloud around our sun. A natural random event looks (from a distance) like a technological structure, resulting in a tech-advanced species inventing a technological structure that looks (from a distance) like a natural random event.<o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>spike <o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'> . </span><span style='font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=gmail-p2><span style='font-family:"Arial",sans-serif'><a href="https://arxiv.org/pdf/1708.07556.pdf">https://arxiv.org/pdf/1708.07556.pdf</a><o:p></o:p></span></p><p class=gmail-p2><span style='font-size:13.5pt;font-family:"Arial",sans-serif'>John K Clark</span><span style='font-family:"Arial",sans-serif'><o:p></o:p></span></p></div><div><div><div><p class=MsoNormal> <o:p></o:p></p></div></div></div></div></div></body></html>