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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><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"'> <a href="mailto:extropy-chat-bounces@lists.extropy.org">extropy-chat-bounces@lists.extropy.org</a> <a href="mailto:[mailto:extropy-chat-bounces@lists.extropy.org]">[mailto:extropy-chat-bounces@lists.extropy.org]</a> <b>On Behalf Of </b>Stefano Vaj<br><b>Sent:</b> Tuesday, May 01, 2012 4:48 AM<br><b>To:</b> ExI chat list<br><b>Subject:</b> Re: [ExI] Milky Way escape velocity<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On 30 April 2012 22:49, BillK <<a href="mailto:pharos@gmail.com" target="_blank">pharos@gmail.com</a>> wrote:<o:p></o:p></p><p class=MsoNormal>We recently mentioned the velocity required to escape the Milky Way<br>galaxy - over 1 million miles per hour.<br clear=all><o:p></o:p></p></div><p class=MsoNormal><br>Million? miles?! hour? <span style='color:#1F497D'>…</span>-- <br>Stefano Vaj<o:p></o:p></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'>>…</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>BOTECs in round numbers that I can recall, the distance from the sun to the center of the Milky Way is about 27,000 years</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>…</span><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'>spike<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'>>…</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I don’t know where I went wrong, but this calc feels like it is off an order of magnitude to the low side. I think escape velocity from here is more like 400 km/sec. What did I do wrong?<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'>Doh! Forgot to multiply by 2 pi. So the tangential velocity out here is more like 600 micro-c or about 200 km/sec and escape velocity is more like 300 km/sec. That sounds more like it. that 40 km/sec scared me: we might wander close enough to something massive and get kicked off the star island.<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'>spike<o:p></o:p></span></p></div></body></html>