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Apr30-04, 02:01 AM   #11
 
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In message &lt;c6eegb\\$j2l\\$1@lfa222122.richmond.edu&gt;,\nebunn@lfa221051.richm ond.edu writes\n&gt;In article &lt;c6anrs\\$58f\\$2@wnnews.sci.kun.nl&gt;,\n&gt;Jasper Stein &lt;jasper.jasper@cs.cs.kun.kun.nl.nl&gt; wrote:\n&gt;\n&gt;&gt;??? I thought the neutrino background +has+ been observed (and is about\n&gt;&gt;1.7K)?\n&gt;\n&gt;\n&gt;Not that I\'ve heard. I\'d be utterly shocked if this were the case.\n&gt;The neutrinos in the cosmic neutrino background have energies less\n&gt;than an meV (m for "milli-"). Neutrinos that we can actually detect\n&gt;are in the MeV range (or at least hundreds of keV).\n&gt;\n&gt;There is strong indirect evidence that the cosmic neutrino background\n&gt;exists, or at least that it existed when the Universe was about a\n&gt;second old. If it weren\'t there, then the amounts of various light\n&gt;elements produced in big-bang nucleosynthesis would be all wrong. But\n&gt;while that\'s strong evidence for the CNB, I wouldn\'t count it as a\n&gt;"detection."\n&gt;\n\nYou gave a figure for energy in neutrinos, which I assume was based on\nthe neutrino having zero mass, but do we have any idea how much missing\nmatter there may be in cold neutrinos if neutrinos have mass?\n\n\n\nRegards\n\n--\nCharles Francis\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>In message <c6eegb$j2l$1@lfa222122.richmond.edu>,
ebunn@lfa221051.richmond.edu writes
>In article <c6anrs$58f$2@wnnews.sci.kun.nl>,
>Jasper Stein <jasper.jasper@cs.cs.kun.kun.nl.nl> wrote:
>
>>??? I thought the neutrino background [itex]+has+[/itex] been observed (and is about
>>1.7K)?

>
>
>Not that I've heard. I'd be utterly shocked if this were the case.
>The neutrinos in the cosmic neutrino background have energies less
>than an meV (m for "milli-"). Neutrinos that we can actually detect
>are in the MeV range (or at least hundreds of keV).
>
>There is strong indirect evidence that the cosmic neutrino background
>exists, or at least that it existed when the Universe was about a
>second old. If it weren't there, then the amounts of various light
>elements produced in big-bang nucleosynthesis would be all wrong. But
>while that's strong evidence for the CNB, I wouldn't count it as a
>"detection."
>


You gave a figure for energy in neutrinos, which I assume was based on
the neutrino having zero mass, but do we have any idea how much missing
matter there may be in cold neutrinos if neutrinos have mass?



Regards

--
Charles Francis