<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</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>Alfio Puglisi<br><b>Sent:</b> Monday, September 02, 2013 10:01 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><div><p class=MsoNormal>On Mon, Sep 2, 2013 at 4:48 PM, spike <<a href="mailto:spike66@att.net" target="_blank">spike66@att.net</a>> wrote:<o:p></o:p></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'><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>I haven't worked out the details on whether colliding two stars would cause<br>a nova (note difference between nova and supernova.) I suspect any star<br>collision would cause a nova, but that is not a show stopper I wouldn't<br>think.<o:p></o:p></p></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Have you heard of "blue stragglers" ? Star merging may occur naturally in sufficiently dense environments. See <a href="https://en.wikipedia.org/wiki/Blue_straggler">https://en.wikipedia.org/wiki/Blue_straggler</a><o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Alfio<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'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Cool thanks Alfio. I did some BOTECs on this notion and found something yesterday which they vaguely hint at in your article, the fast spin. I was trying to determine if the induced close encounter between two stars would transfer mass from the smaller to the larger under all circumstances. Turns out it’s the other way around under most circumstances as far as I can tell, but what I was doing is figuring out if we could use angular momentum to do what I suggested yesterday, create a smaller mass star while keeping our modest forward speed, which took 20 million years to accumulate.<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'>There is one other question I still have no insights on how to calculate. If we induce a very close encounter between stars, transfer some mass from the more massive star, we really get the less massive star spinning wildly. That would (I think) cause that star to stay on the main sequence longer, since its pressure gradient would be decreased: the center of that star is at lower pressures than it would be if its sidereal motion is zero.<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'>I will post later on that if I manage to model this successufully and solve the equations, no guarantee. Some of you hipsters, do feel free to scoop me on that.<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></div></div></body></html>