Kefka G
Oct29-04, 02:07 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>\n\nWe hear about extra spatial dimensions all the time, but what is the word on\nextra temporal dimensions? I\'m sure people have investigated them and deemed\nthem not very useful in physics, but I\'m curious nonetheless what people have\nfigured out about how a physical theory would work in, for instance, two time\ndimensions. I\'ve heard tell that field theories don\'t work so well in general,\ndue to existence problems, but it seems to me that this would be highly\ndependent on the type of initial data selected. Even at the\nclassical/relativistic level, I\'m having some difficulty figuring out how\nthings would look - it seems like a "particle\'s" world line would have to\nbecome a world sheet, we\'d have to think about observer trajectories through\ntime, and we\'d clearly lose things like causality, but is there a fatal\ntheoretical flaw with such theories, other than that they don\'t describe\nreality as we know it? If we assume a very tiny extra time dimension, do we\nget a Kaluza-Klein type situation where we "hardly" notice the extra dimension\nas long as it\'s real small? ("hardly" meaning that perhaps we see a\n"fictitious" field or something like that) Any info or references would be\nappreciated...\n\n-Eric\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>We hear about extra spatial dimensions all the time, but what is the word on
extra temporal dimensions? I'm sure people have investigated them and deemed
them not very useful in physics, but I'm curious nonetheless what people have
figured out about how a physical theory would work in, for instance, two time
dimensions. I've heard tell that field theories don't work so well in general,
due to existence problems, but it seems to me that this would be highly
dependent on the type of initial data selected. Even at the
classical/relativistic level, I'm having some difficulty figuring out how
things would look - it seems like a "particle's" world line would have to
become a world sheet, we'd have to think about observer trajectories through
time, and we'd clearly lose things like causality, but is there a fatal
theoretical flaw with such theories, other than that they don't describe
reality as we know it? If we assume a very tiny extra time dimension, do we
get a Kaluza-Klein type situation where we "hardly" notice the extra dimension
as long as it's real small? ("hardly" meaning that perhaps we see a
"fictitious" field or something like that) Any info or references would be
appreciated...
-Eric
extra temporal dimensions? I'm sure people have investigated them and deemed
them not very useful in physics, but I'm curious nonetheless what people have
figured out about how a physical theory would work in, for instance, two time
dimensions. I've heard tell that field theories don't work so well in general,
due to existence problems, but it seems to me that this would be highly
dependent on the type of initial data selected. Even at the
classical/relativistic level, I'm having some difficulty figuring out how
things would look - it seems like a "particle's" world line would have to
become a world sheet, we'd have to think about observer trajectories through
time, and we'd clearly lose things like causality, but is there a fatal
theoretical flaw with such theories, other than that they don't describe
reality as we know it? If we assume a very tiny extra time dimension, do we
get a Kaluza-Klein type situation where we "hardly" notice the extra dimension
as long as it's real small? ("hardly" meaning that perhaps we see a
"fictitious" field or something like that) Any info or references would be
appreciated...
-Eric