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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>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? I could do the math, but while it sounds much, I do not have from the top of my head the vaguest idea of the fraction of c we are discussing here... :-)<br><br>-- <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'>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, and the orbit period is about 250 million years, so the orbit speed is about 0.1 milli-c, and escape velocity from any round orbit is square root 2 times the tangential velocity so escape velocity from here would be about 140 micro-c, and a micro-c is about .3 km/sec so escape is about 40 km/sec.<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>