PDA

View Full Version : Momentum on the circle

mandro
Oct5-04, 06:42 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>I was wondering: How would "beings" living on\na circle measure momentum? I.e., what\'s the\noperational definition of measuring momentum\nWould they be able to do it at all? If the notion\nof momentum is to have any physical significance\nto these "beings" they must have an operational\ndefinition of "measuring momentum". I\'m wondering\nwhat its is. If there are various definitions,\nI\'d like to hear some of them.\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>I was wondering: How would "beings" living on
a circle measure momentum? I.e., what's the
operational definition of measuring momentum
Would they be able to do it at all? If the notion
of momentum is to have any physical significance
to these "beings" they must have an operational
definition of "measuring momentum". I'm wondering
what its is. If there are various definitions,
I'd like to hear some of them.
Frank Hellmann
Oct6-04, 08:03 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>Organization: (no organization specified)\nmandro &lt;ultraman2002@hotmail.com&gt; wrote in message news:&lt;cju1ag\\$tsi\\$1@lfa222122.richmond.edu&gt;...\ n&gt; I was wondering: How would "beings" living on\n&gt; a circle measure momentum? I.e., what\'s the\n&gt; operational definition of measuring momentum\n&gt; Would they be able to do it at all? If the notion\n&gt; of momentum is to have any physical significance\n&gt; to these "beings" they must have an operational\n&gt; definition of "measuring momentum". I\'m wondering\n&gt; what its is. If there are various definitions,\n&gt; I\'d like to hear some of them.\n\nI assume you mean that their physics is rotationally invariant. Then\ntheir problem is precisely the same as ours.\nAbsolutel momentum (in Newtonian theory for simplicity) is irrelevant,\nbecause you can always view the physics in any inertial system where\nthe overall momentum might take any particular value. Only relative\nmomentum can be meassured, and there beings on a circle would have no\nmore or less problems then beings on a straight line.\n\nIf that missed your question please clarify.\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>Organization: (no organization specified)
mandro <ultraman2002@hotmail.com> wrote in message news:<cju1ag$tsi$1@lfa222122.richmond.edu>...
> I was wondering: How would "beings" living on
> a circle measure momentum? I.e., what's the
> operational definition of measuring momentum
> Would they be able to do it at all? If the notion
> of momentum is to have any physical significance
> to these "beings" they must have an operational
> definition of "measuring momentum". I'm wondering
> what its is. If there are various definitions,
> I'd like to hear some of them.

I assume you mean that their physics is rotationally invariant. Then
their problem is precisely the same as ours.
Absolutel momentum (in Newtonian theory for simplicity) is irrelevant,
because you can always view the physics in any inertial system where
the overall momentum might take any particular value. Only relative
momentum can be meassured, and there beings on a circle would have no
more or less problems then beings on a straight line.

If that missed your question please clarify.