<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div style="-webkit-text-size-adjust: auto;"><span></span></div><div style="-webkit-text-size-adjust: auto;"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div><div><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">On Wednesday, October 8, 2014 3:38 AM, Anders Sandberg <<a href="mailto:anders@aleph.se" x-apple-data-detectors="true" x-apple-data-detectors-type="link" x-apple-data-detectors-result="1">anders@aleph.se</a>> wrote:<br></span></font></blockquote><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">Dan<<a href="mailto:danust2012@gmail.com" x-apple-data-detectors="true" x-apple-data-detectors-type="link" x-apple-data-detectors-result="2">danust2012@gmail.com</a>> , 8/10/2014 1:57 AM:</span></font></blockquote><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);"><br></span><blockquote type="cite"><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">Just speculating: Could GRBs have secondary effects on planetary<br></span></font></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">systems, such as burning off too many volatiles (which are then<br></span></font></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">not available, say, for cometary impacts on young worlds?) and<br></span></font></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">shaking up stability (say, causing another heavy bombardment in<br></span></font></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">a system by knocking asteroids off stable/nonintersecting orbits)?></span></font></blockquote></blockquote><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);"><br></span><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">No. 100 kJ/m^2 deposited in a few seconds is only about 100<br></span></font></blockquote><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">times the solar heating: not enough to vaporize much, and the<br></span></font></blockquote><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">lost volatiles can start condensing immediately. A 20 second<br></span></font></blockquote><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">burst can ideally vaporize 705 g/m^2 of ice, less than a cm deep.</span></font></blockquote><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);"><br>I'm wondering if it's enough to do widespread damage -- not necessarily burn everything off. Obviously, a GRB hit in early solar system development might have a bigger impact, though it'd have to get through higher densities of gas and dust. Then again, this might be a double-edged sword -- maybe helping to trigger more planet formation, so not necessarily a filter against complex life. (Presuming planet formation is, overall, better for the formation of complex life.)<br><br></span><blockquote type="cite"><font color="#000000"><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);">Closer to the burst things might be worse, of course.</span></font></blockquote><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);"><br>Closer would be worse, yes, though I was wondering about something would be widespread enough to act as _the_ filter. Reckon this ain't it.<br><br>Regards,<br><br>Dan</span></div></div></div><div><span style="-webkit-text-size-adjust: auto; background-color: rgba(255, 255, 255, 0);"> My nanotech apocalypse story "Succession" can be previewed at:<br></span><a href="http://www.amazon.com/Succession-ebook/dp/B00F02DLNG" x-apple-data-detectors="true" x-apple-data-detectors-type="link" x-apple-data-detectors-result="0" style="-webkit-text-size-adjust: auto;">http://www.amazon.com/Succession-ebook/dp/B00F02DLNG</a></div></body></html>