<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><div class="" style="font-size:12.8px;font-family:arial,sans-serif"><br class=""><table cellpadding="0" class=""><tbody><tr class=""><td class="" style="width:495.333px"><br></td><td class=""><br></td><td class=""><br></td><td class="" rowspan="2"><br></td></tr><tr class=""><td colspan="3"></td></tr></tbody></table></div><div id=":192" class="" style="font-size:12.8px;font-family:arial,sans-serif"><div id=":191" class=""><div dir="ltr"><span class="im"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><span style="font-family:arial,sans-serif;font-size:12.8px">Ethan Siegel discusses why black holes = dark matter is unlikely.</span><br style="font-family:arial,sans-serif;font-size:12.8px"><span style="font-family:arial,sans-serif;font-size:12.8px"><</span><a href="http://www.forbes.com/sites/startswithabang/2016/05/26/black-holes-as-dark-matter-heres-why-the-idea-falls-apart/#687e2a006d7b" rel="noreferrer" target="_blank" style="font-family:arial,sans-serif;font-size:12.8px">http://www.forbes.com/sites/startswithabang/2016/05/26/black-holes-as-dark-matter-heres-why-the-idea-falls-apart/#687e2a006d7b</a><span style="font-family:arial,sans-serif;font-size:12.8px">></span><br></div><div class="gmail_extra"><br></div></span><div class="gmail_extra"><div class="gmail_quote"><br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​> ​</div><span class="im">All told, observations of<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>the lack of Hawking radiation,<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>gamma-ray-burst microlensing,<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>neutron star capture in globular clusters,<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>traditional microlensing,<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>and the cosmic infrared and microwave backgrounds,<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>tell us that we can’t have primordial black holes make up the majority<div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​ ​</div>of dark matter over a wide variety of mass ranges.<br></span></blockquote><div><br></div><div><br></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​<font size="4">That's true, ​</font></div><font size="4"> <div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​all those things do rule out Black Holes being Dark Matter over a </div><span class="im">wide variety of mass ranges</span><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline">​,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"> but not over all mass ranges. To be Dark Matter Black Holes can't be smaller than 10 solar masses and they can't be larger than 100. But LIGO found a 29, a 36, and a 62 solar mass Black Hole almost as soon as it was turned on.</div></font></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><font size="4"><br></font></div></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><font size="4">  John K Clark</font></div></div><div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;display:inline"><font size="4"><br></font></div></div><div><br></div></div></div></div></div></div></div></div>