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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><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"'> spike <spike66@att.net><br><b><span style='color:#1F497D'>…</span></b></span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><br><br><br>>>Interesting thought experiment: imagine the moon to be a perfectly spherical<br>polished mirror surface of 100 percent reflectivity in all wavelengths.<br>What would it look like from here? <span style='color:#1F497D'>... </span>spike<br><br></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'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><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>Dan<br><b>Subject:</b> Re: [ExI] destiny's road: was RE: rebuilding a saturn v today<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:#1F497D'>>…</span><span style='font-family:"Arial","sans-serif"'>What about the effect of light from other stars?<span style='color:#1F497D'> </span>Regards,<span style='color:#1F497D'> </span>Dan<span style='color:#1F497D'><o:p></o:p></span></span></p></div><div><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'>We wouldn’t be able to see it except during a total eclipse, at which time the view would be remarkable indeed. The earth’s reflection would appear as a bright blue dot of apparent diameter of about 300 microradians, definitely resolvable as a circle, with innumerable tiny pinpoints of light, each about 1% the brightness of star we see. The reflected images of stars would be closer together but still approximately the same average brightness at the perimeter of the polished moon’s disk, so that it would form a kind of halo around the earth’s reflection of about 11 milliradians apparent diameter. That would be a startling sight indeed.<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'>Any other time besides a total eclipse the reflection of the stars would not be visible, for the same reason we can’t see stars in the daytime now. I haven’t done the calcs, but I wouldn’t be at all surprised if the star images would be drowned out by light from the sun’s corona even at a total eclipse.<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'>A related and interesting thought question would be: imagine the earth polished to a mirror ball. What would it look like from the moon? Again it would be a point of light always, but brighter, ~4% the brightness of the sun. But in a total lunar eclipse, the reflection of the moon would disappear and we could see the reflection of the cumulative light from a billion stars, growing brighter toward the periphery to form a 33 milliradian halo, surrounding millions of points of light.<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><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'><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'><o:p> </o:p></span></p></div><div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'><br><br><o:p></o:p></span></p></div></div></div></div></body></html>