Cosmic rays and strings [Archive]

alistair

Apr29-04, 02:51 PM

<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>What do the string theories have to say about something like the GZK\nparadox where ultra high energy cosmic ray protons reach the Earth when\nthey should have been absorbed by the cosmic microwave background?\n\n\n[Moderator\'s note: because this question contains the words "string\ntheories", it was not classified as off-topic, but I am pretty curious\nwhether someone is able to propose a stringy explanation of these\nphenomena. ;-) LM]\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">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>What do the string theories have to say about something like the GZK
paradox where ultra high energy cosmic ray protons reach the Earth when
they should have been absorbed by the cosmic microwave background?

[Moderator's note: because this question contains the words "string
theories", it was not classified as off-topic, but I am pretty curious
whether someone is able to propose a stringy explanation of these
phenomena. ;-) LM]

Edward Witten

May11-04, 09:29 PM

<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>alistair <alistair@goforit64.fsnet.co.uk> wrote in message news:<861c1b21.0404291048.2658d8c4-100000@posting.google.com>...\n\n> What do the string theories have to say about something like the GZK\n> paradox where ultra high energy cosmic ray protons reach the Earth when\n> they should have been absorbed by the cosmic microwave background?\n\nIt is not clear at the moment that there is anything to explain.\nOne of the two main experimental groups (AGASA) reported\nas of over a year ago that their high energy data are in accord\nwith the expected GZK cutoff. The other group continues\nto report a discrepancy. We\'ll see what happens as data improve.\nEdward Witten\n\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">  View this Usenet post in original ASCII form </a></div><P></jabberwocky>alistair <alistair@goforit64.fsnet.co.uk> wrote in message news:<861c1b21.0404291048.2658d8c4-100000@posting.google.com>...

> What do the string theories have to say about something like the GZK
> paradox where ultra high energy cosmic ray protons reach the Earth when
> they should have been absorbed by the cosmic microwave background?

It is not clear at the moment that there is anything to explain.
One of the two main experimental groups (AGASA) reported
as of over a year ago that their high energy data are in accord
with the expected GZK cutoff. The other group continues
to report a discrepancy. We'll see what happens as data improve.
Edward Witten