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</o:shapelayout></xml><![endif]--></head><body bgcolor=white 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><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext'> extropy-chat [mailto:extropy-chat-bounces@lists.extropy.org] <b>On Behalf Of </b>Anders Sandberg<br><b>Sent:</b> Thursday, February 11, 2016 3:29 PM<br><b>To:</b> extropy-chat@lists.extropy.org<br><b>Subject:</b> Re: [ExI] Gravitational Waves Detected By LIGO!<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>On 2016-02-11 17:50, spike wrote:<br><br><o:p></o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal><span style='color:#1F497D'>Anders, cool, but we need to know how GW energy would interact with matter before we conclude that it would nuke biomes.</span><o:p></o:p></p></blockquote><p class=MsoNormal><br><span style='color:#1F497D'>>…</span>OK, I was using the normal style of energy estimates used in supernova xrisk considerations.<br><br><span style='color:#1F497D'>>…</span>Now, for gravitational waves being lethal, the strain must presumably be large enough to cause induction of forces that are damaging. To a ~1 m object like a human, you probably need a strain on the order of more than 1/100 to induce damage (1/10 seems really likely to do it). The strain scales as 1/r, so given that the detected strain here was on the order of 10^-19, we get dangerous strain when 10^17 times closer to the source (which is at around 410 Mpc). That is, we get dangerous strain within <span class=cwcot>126,526 kilometers. </span><br><br><span class=cwcot><span style='color:#1F497D'>>…</span></span><span class=cwcot>So I would not worry about gravity waves. </span><br><span style='color:#1F497D'>…</span><br>-- <o:p></o:p></p><pre>Anders Sandberg<o:p></o:p></pre><pre><span style='color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Cool, thanks I am feeling better already.<o:p></o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>When I was doing these calcs a long time ago it was before the internet really amounted to much of anything. I don’t recall using the strain criterion. Really don’t remember how the hell I figured it out and can’t find the calcs. I found the notebooks from that timeframe, but not those BOTECs. <o:p></o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Shows to go ya: write it in some form you can retrieve it later.<o:p></o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Now that I think about it, I have never seen merging black holes or GWs as an explanation for the silence of the cosmos.<o:p></o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Oh this is a fun time to be alive, oh my, oooooooh what an orgasmic time to be here.<o:p></o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>spike<o:p></o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre><pre><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></pre></div></body></html>