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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"'>>…</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <b>On Behalf Of </b>Tomaz Kristan<br><b>Subject:</b> Re: [ExI] kepler study says 8.8e9 earthlike planets<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal style='margin-bottom:12.0pt'>><span style='color:#1F497D'>>…</span> A double-Earth would likely be a waterworld, from what I have read. Rock after all contains water, and if you squeeze it enough it will be released to the surface (plus cometary water). So double-Earth will at least have eight times the water volume but just four times the surface area.<br><br><span style='color:#1F497D'>></span>> Plenty of volcanism, and over time I think continents will develop. Mountains would be half of our height (since gravity would be twice as large), but that is still enough to get some to poke up. Dr Anders Sandberg<o:p></o:p></p></div><p class=MsoNormal><span style='color:#1F497D'>>…</span>Twice as much water is 8 km deep on average. 4 km above Earth ocean surface. And mountains half as big, not even Mont Everest would be above water.<span style='color:#1F497D'> </span>-- <span style='color:#1F497D'> Tomaz<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'>Hmmm, it might work that way, but it isn’t clear. Increased gravity would reduce the altitude of the mountains, but it would also decrease the depths of the deepest parts of the sea, so the same amount of water might cover more land. A double earth with twice the radius of earth (and 8 times the mass and 8 times the water) might have no dry continents.<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'>Since we know think there are many Goldilocks planets and there is justification for thinking they have similar composition to the earth for all the same reasons, and since Kepler is proportionally capable of discovering larger planets, we can extrapolate to plenty of larger Goldies. From that I get to a lot of water worlds. <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'>Since we started the thread regarding the need for dry land for the evolution of intelligent life, I have been thinking about all the possibilities: life can evolve in the seas of course, but as far as I know, biogenesis theory requires dry land for tidal pools to concentrate organic matter, and I don’t think ice gets it done. So if there are no islands and ice caps don’t help, are there any other possibilities? I thought of one: floating pumice islands. I am not referring to the floating island of Guam, which representative Johnson fears will capsize at 1:20 in this video:<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 href="https://www.youtube.com/watch?v=v7XXVLKWd3Q">https://www.youtube.com/watch?v=v7XXVLKWd3Q</a><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'>({8^D heeeeeeheheheheheeeeeeehaaaaahahahahahaaaaaheh}<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'>But rather a floating pumice raft such as the one formed in 2006 near Tonga:<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 href="http://en.wikipedia.org/wiki/Pumice_raft">http://en.wikipedia.org/wiki/Pumice_raft</a><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 href="http://www.livescience.com/22268-huge-pumice-island-floats-in-pacific.html">http://www.livescience.com/22268-huge-pumice-island-floats-in-pacific.html</a><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 href="http://www.space.com/15491-volcanic-rock-microbes-life.html">http://www.space.com/15491-volcanic-rock-microbes-life.html</a><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'>So if pumice rafts could perhaps have had some role in biogenesis, then it feels like a reasonable extrapolation that a pumice raft could eventually form a stable land mass on a water planet under some conditions, such as: the salinity of the sea is much higher than the earth’s so its freezing point is lower, and the planet is colder, then the rain and snow falling on the pumice raft would freeze (being fresh water) which would cement the mass together and cause more pumice to collect underneath it, raising the whole dirty snowball, making it an even better place for rain and snow to collect.<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'>Or it could be I am working too hard to imagine intelligent life on a water planet.<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></div></div></body></html>