[SOLVED] Is 'Time' a function of 'Mass?' [Archive]

R. Henry Nigl

May1-04, 07:52 AM

<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>Looking for direction for a discussion or proof that Time is (or is not) a\nfunction of Mass. (ie. aggregation of Matter).\n\nThanks,\nRHN\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>Looking for direction for a discussion or proof that Time is (or is not) a
function of Mass. (ie. aggregation of Matter).

Thanks,
RHN

Frank Hellmann

May3-04, 06:41 AM

<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>\nThe eigentime tau of an object (that is, the time that passes for an\nobserver sitting at the object) varies depending on the presence of\nmasses around it in GR.\n\nFor exampole the schwartzschild metric describes the movement of\nobjects around a spherical mass distribution at the origin:\n\nds^2 = dtau^2 = 1/(1-2M/r) dr^2 + r^2 domega^2 - (1-2M/r)dt^2\n\nWhere t is the time at infinity, i.e. in the absence of mass.\n\nSo the eigentime elapsed is a function of the mass (or better:\ndensity) distribution.\n\nThe coordinate time (here chosen as the eigentime at infinity) is a\nphysically meaningless but convenient choice (that it is convenient is\nnot entirely meaningless though).\n\n\n--\nenjoy,\nFrank Hellmann\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>The eigentime \tau of an object (that is, the time that passes for an
observer sitting at the object) varies depending on the presence of
masses around it in GR.

For exampole the schwartzschild metric describes the movement of
objects around a spherical mass distribution at the origin:

ds^2 = dtau^2 = 1/(1-2M/r) dr^2 + r^2 domega^2 - (1-2M/r)dt^2

Where t is the time at infinity, i.e. in the absence of mass.

So the eigentime elapsed is a function of the mass (or better:
density) distribution.

The coordinate time (here chosen as the eigentime at infinity) is a
physically meaningless but convenient choice (that it is convenient is
not entirely meaningless though).

--
enjoy,
Frank Hellmann

alistair

May6-04, 12:19 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>In special relativity time is not a function of mass because special\nrelativity\nassumes that there is no gravitational field present.But where in the\nuniverse can you go where there is no gravitational field? So I would\nsay that time is always a function of mass.\n\n[Moderator\'s note: The sentence "time is a function of mass" doesn\'t\nseem to have a unique, clear meaning, as far as I can tell. Anyone\nthinking of responding should take care to define his or her terms\nvery explicitly. -TB]\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>In special relativity time is not a function of mass because special
relativity
assumes that there is no gravitational field present.But where in the
universe can you go where there is no gravitational field? So I would
say that time is always a function of mass.

[Moderator's note: The sentence "time is a function of mass" doesn't
seem to have a unique, clear meaning, as far as I can tell. Anyone
thinking of responding should take care to define his or her terms
very explicitly. -TB]